Geology, Volcanism and Humans

[old_pop2000]

Just thought we could get back to discussing some of our favorite subjects.

The two 5.0 + earthquakes that occurred a week ago 22 miles south of Mexicali/Calexico are now being classified as an earthquake flurry or swarm. There have been over 100 smaller earthquakes in the area.

[Kyle Holgate]

I've been watching the patterns of quakes in California with interest. Things seem to be slightly shakier than has been the norm since I started monitoring such things many years ago. One pattern that is appearing that is interesting and a bit confusing is that there seems to be a line of very small quakes forming on a line running NE to SW from roughly the Sierras toward Bakersfield. The faults go N/S so a line of quakes along a fault should show a north/south trend. This one is probably just a random pattern that happens to form a line but it sure seems like it's heading to "cut California in half". Not that it'd be a bad thing I suppose. Chop off the Northern part and let it join with the PacNW and let the other part be called Fruitloopia or something new. ;)

[old_pop2000]

The area around the 2004 Indonesian earthquake that generated the Tsunami, had a preliminary 7.5. It was centered about 195 miles SSE of Banda Aceh. This was the center of the last 9.0 earthquake. This was was centered on the north shore of the Island of Simeuleu.

Also, the area south of Mexicali, Mexico on the border had another 5.0 along with 20 aftershocks. This is the area near San Diego that is having an earthquake swarm.


Geology is a lively endeavor. Right, Mike D.

[old_pop2000]

Paper on pre-Grand Canyon Colorado River:D

http://www.gsajournals.org/archive/1052-5173/18/3/pdf/i1052-5173-18-3-4.pdf

[Kyle Holgate]

Paper on pre-Grand Canyon Colorado River:D

http://www.gsajournals.org/archive/1052-5173/18/3/pdf/i1052-5173-18-3-4.pdf

The Science channel or National geographic channel had a show on the geology of the GC late last week. Intersting how they can tell there was a major mountain range there which is now at the bottom of the canyon as well as track the uplifting of the western US. I've often found the basin & range area - what exactly is going on there? The rifting wayyyy down under the central US too is curious. Is it a failed rift as some suggest or an actual rift under construction as others see it. I'm speaking here of the New Madrid area quakes.

[old_pop2000]

I believe the jury is still out on the New Madrid area. It might be a rift that is still attempting to split the continent apart.

[Kyle Holgate]

I believe the jury is still out on the New Madrid area. It might be a rift that is still attempting to split the continent apart.

Another biiiig question that I think the science of geology is "in the dark" on is flood basalts. They don't happen too often and once finished - don't appear to repeat in the same spot like the so called super volcanoes, but to have a flood basalt eruption today just about anywhere would likely still be a global catastrophy. What makes them though? We know about (IIRC) over a dozen hot spots and they don't seem to be related. Arguably the Yellowstone hot spot could have been related to the flood basalts in east/central Washington & Oregon (trace back the hot spot throug the snake river plane, it seems to appear in Oregon about where the basalts were originating).

It's interesting being in on the ground floor of science. We're so green when it comes to Geology and with the internet so much is now accessable instead of only published in select journals. I have trouble figuring out which I find more interesting - Geology or Astronomy - so I call 'em both a tie and try to keep up on them. Fascinating stuff. One plus though, I have access to geology and can poke around on a volcano any time I have a day off work. With Astronomy my access is much more limited! I do like my 4.5 inch rich field scope, but I also dream of having a bigger one (telescope! Telescope! don't get any ideas!).

[old_pop2000]

Another biiiig question that I think the science of geology is "in the dark" on is flood basalts. They don't happen too often and once finished - don't appear to repeat in the same spot like the so called super volcanoes, but to have a flood basalt eruption today just about anywhere would likely still be a global catastrophy. What makes them though? We know about (IIRC) over a dozen hot spots and they don't seem to be related. Arguably the Yellowstone hot spot could have been related to the flood basalts in east/central Washington & Oregon (trace back the hot spot throug the snake river plane, it seems to appear in Oregon about where the basalts were originating).

It's interesting being in on the ground floor of science. We're so green when it comes to Geology and with the internet so much is now accessable instead of only published in select journals. I have trouble figuring out which I find more interesting - Geology or Astronomy - so I call 'em both a tie and try to keep up on them. Fascinating stuff. One plus though, I have access to geology and can poke around on a volcano any time I have a day off work. With Astronomy my access is much more limited! I do like my 4.5 inch rich field scope, but I also dream of having a bigger one (telescope! Telescope! don't get any ideas!).
I concur about the internet and published information, it is a boon to those of us who have wide interests in various scientific subjects like geology, meteorology, climatology, astronomy.

What kind of telescope do you have? Newtonian, cassegrain or a simple refractor. Do you use a alta-azimuth or an equatorial mount? Motor driven or manual? Do you a computer control system?

I purchased Starry Night a few years ago, I enjoy that.

[old_pop2000]

Well, even the English are getting into the earthquake game.

http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008nyae.php

[Kyle Holgate]

I concur about the internet and published information, it is a boon to those of us who have wide interests in various scientific subjects like geology, meteorology, climatology, astronomy.

What kind of telescope do you have? Newtonian, cassegrain or a simple refractor. Do you use a alta-azimuth or an equatorial mount? Motor driven or manual? Do you a computer control system?

I purchased Starry Night a few years ago, I enjoy that.

My scope is a 4.5" rich field reflector scope. Look at Edmund scientific - Astorscan - that's what I have! I like it, I can bang it up a bit and it's extremely easy to just toss in the car and go. I miss having an equatorial mount and finder scope and more light gathering ability (used to have a celestron 8") but at least I can actually move this around and use it.

I have been seriously thinking about getting starry night, but I hate that you can't "test drive" software and send it back if you don't like it. Then again if you like it, I probably would too - I we have similar interests.

Yeah, England. One of the oldest areas still on the surface of the planet - and even they get to boogy on occasion! What I've been wondering is why Iceland has been so quiet for so long. Seems like they're due for an eruption of there (or past due).

[old_pop2000]

My scope is a 4.5" rich field reflector scope. Look at Edmund scientific - Astorscan - that's what I have! I like it, I can bang it up a bit and it's extremely easy to just toss in the car and go. I miss having an equatorial mount and finder scope and more light gathering ability (used to have a celestron 8") but at least I can actually move this around and use it.

I have been seriously thinking about getting starry night, but I hate that you can't "test drive" software and send it back if you don't like it. Then again if you like it, I probably would too - I we have similar interests.

Yeah, England. One of the oldest areas still on the surface of the planet - and even they get to boogy on occasion! What I've been wondering is why Iceland has been so quiet for so long. Seems like they're due for an eruption of there (or past due).
Thanks, I will look at that. One of these days I am going to buy a nice Newtonian 4 or 5 inch, with equitorial mounting, auto control from a computer.

Interesting article about a supercomputer and an 9.0 earthquake in the Northwest

http://www.eurekalert.org/pub_releases/2008-02/uoc--suv022608.php

[Ed Rotondaro]

Thanks, I will look at that. One of these days I am going to buy a nice Newtonian 4 or 5 inch, with equitorial mounting, auto control from a computer.

Interesting article about a supercomputer and an 9.0 earthquake in the Northwest

http://www.eurekalert.org/pub_releases/2008-02/uoc--suv022608.php

Dennis:

I'll bet that is one seriously complex piece of modeling software.

[Ed Rotondaro]

Well, even the English are getting into the earthquake game.

http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008nyae.php

Dennis:

I saw the TV coverage of that. Appears no major damage or injuries.

[Kyle Holgate]

Thanks, I will look at that. One of these days I am going to buy a nice Newtonian 4 or 5 inch, with equitorial mounting, auto control from a computer.

Interesting article about a supercomputer and an 9.0 earthquake in the Northwest

http://www.eurekalert.org/pub_releases/2008-02/uoc--suv022608.php

Mt. Rainier has formed much of the land that Tacoma and a good chunck of Seattle set on. You can see the flat, Lahar depost area on the way up (and I drive by frequently these days). Portland has a lot of land on valley floor mud much of which was laid down by the missoula floods 10,000 years ago. Luckily for Portland though, a fair sized chunk of the city is on basalt - volcanic rock that erupted from one or more of the dozen (or more) volcanic vents in and around the city. At least on the rock you would't get the "jello effect" where the jiggle from the quake is amplified!
Where I live in Beaverton (not far west of Portland) I am sitting on an old basalt flow + forest debris based soil. The building I live in is suspect - at least being in the top floor apt I get to land on everyone else not the other way around.

[Kyle Holgate]

Dennis:

I saw the TV coverage of that. Appears no major damage or injuries.

http://neic.usgs.gov/neis/eq_depot/2008/eq_080227_nyae/neic_nyae_w.html

Looks like they're in a very low seismic hazard zone, but not at the very bottom like Ireland is. They mainly have to deal with lots of rain and north sea storms once in a while - reminds me of here (OR) - except we get a big honker of a quake every 400 years or so and the occasional volcano going off.

[old_pop2000]

Mt. Rainier has formed much of the land that Tacoma and a good chunck of Seattle set on. You can see the flat, Lahar depost area on the way up (and I drive by frequently these days). Portland has a lot of land on valley floor mud much of which was laid down by the missoula floods 10,000 years ago. Luckily for Portland though, a fair sized chunk of the city is on basalt - volcanic rock that erupted from one or more of the dozen (or more) volcanic vents in and around the city. At least on the rock you would't get the "jello effect" where the jiggle from the quake is amplified!
Where I live in Beaverton (not far west of Portland) I am sitting on an old basalt flow + forest debris based soil. The building I live in is suspect - at least being in the top floor apt I get to land on everyone else not the other way around.
San Diego county's geology is based on a granitic intrusion, part of the batholyth that was pushed up, folded and faulted by the collision of the two continents along the San Andreas. Westward from the Peninsular range running northwest to southeast, is the bulk of the San Diego area faulted by splitter faults like the Rose Canyon. This has faulted and lifted successive sedimentary deposits caused by the raising and lowering of Sea Level. We can see successive shorelines, like the one at La jolla, on the eastern hills from our home which is at the base of the Peninsular range. As you head up northeast, you pass through areas with huge granitic bolders about the size of a diesel semi and larger. All broken and part of that batholyth. Anyway, no volcanic action here except in the deserts to the east with some cinder cones. Everything here, westward is sea floor bottom raised by the bend and subsequent faulting of the San Andreas.

[old_pop2000]

San Diego county's geology is based on a granitic intrusion, part of the batholyth that was pushed up, folded and faulted by the collision of the two continents along the San Andreas. Westward from the Peninsular range running northwest to southeast, is the bulk of the San Diego area faulted by splitter faults like the Rose Canyon. This has faulted and lifted successive sedimentary deposits caused by the raising and lowering of Sea Level. We can see successive shorelines, like the one at La jolla, on the eastern hills from our home which is at the base of the Peninsular range. As you head up northeast, you pass through areas with huge granitic bolders about the size of a diesel semi and larger. All broken and part of that batholyth. Anyway, no volcanic action here except in the deserts to the east with some cinder cones. Everything here, westward is sea floor bottom raised by the bend and subsequent faulting of the San Andreas.
I left off some time periods for these actions. Our earliest sedimentary formations start in the Jurassic that have been slightly metamorphosed along with some volcanics called the Santiago Peak Formation. This is around 147 million years ago when there was a trench off of coast with a line of volcanoes running from Mexico upward to Alaska. Inland of the volcanics, was an inland sea which drained westward. We have later formations in the Cretaceous, including those volcanoes. They are still attempting to decide where those volcanoes fit, but new data shows around 126 million years ago. During much of the Jurassic and Cretaceous period, there was subduction going on with the oceanic plate. This is what formed the trench off of the coast and the volcanics.

Things get far more complicated during the Paleocene and Eocene around here. No more volcanics, start of the successive uplifts of sediments and rise and fall of the oceans along with a change of the movement of the NA plate and Pacific from a subduction to a simple slide pass making the San Andreas Fault Zone.

Anyway, that is a brief on our geology. It is still being unearthed and investigated, especially the flora and fauna.

[Kyle Holgate]

What about that Volcano that went off many years ago from the La brea tar pits - and Tommy lee Jones saved the day? That's not horribly far from Dan Diego.

If you have Granite Batholiths at the surface then that's a pretty good indication that the active volcano days are long over - long enough for erosion and uplifting to get all the way to the roots.

Do you have any of these books?

http://geology.com/store/roadside-geology.shtml

http://geology.com/store/cascade-volcano.shtml

I have 3 of the roadside geology series and a copy of Fire mountains. Good books for geology nuts. I also went to the local community college and bought a Geology textbook. Yeah, what can I say - I am a knowledge junky.


Dennis - about the Telescope. Be sure you get something that is fairly easy to move around and set-up. I found that wiht my Celestron, though it gave fascinating views of things - it was a pain in the butt to do anything with. In contrast, my little Astroscan is so easy to use that it GETS used. I think if I were going to get a new scope - it'd be a 5 or 6" casigrain (celestron or Meade probably) and I'd forgoe the computer guidence as they're not that hard to use manually once you have them aligned. It's pretty easy to just dial in the object and more complication makes them less useful in my experience.

[old_pop2000]

What about that Volcano that went off many years ago from the La brea tar pits - and Tommy lee Jones saved the day? That's not horribly far from Dan Diego.

If you have Granite Batholiths at the surface then that's a pretty good indication that the active volcano days are long over - long enough for erosion and uplifting to get all the way to the roots.

Do you have any of these books?

http://geology.com/store/roadside-geology.shtml

http://geology.com/store/cascade-volcano.shtml

I have 3 of the roadside geology series and a copy of Fire mountains. Good books for geology nuts. I also went to the local community college and bought a Geology textbook. Yeah, what can I say - I am a knowledge junky.


Dennis - about the Telescope. Be sure you get something that is fairly easy to move around and set-up. I found that wiht my Celestron, though it gave fascinating views of things - it was a pain in the butt to do anything with. In contrast, my little Astroscan is so easy to use that it GETS used. I think if I were going to get a new scope - it'd be a 5 or 6" casigrain (celestron or Meade probably) and I'd forgoe the computer guidence as they're not that hard to use manually once you have them aligned. It's pretty easy to just dial in the object and more complication makes them less useful in my experience.
Many of the intrusions are determined to be plutons from the subduction of the oceanic crust, others smaller intrusions after the subduction stopped. The actual batholyths that are inland, pre-date the Jurassic period of sedimentation. Prior to 150 million years ago, most of San Diego was under deep ocean water and bordered the upthrust batholyth. Our geologic history really starts at this point.

I have two roadside geology books; one of Arizona and the other of Oregon. I also have three geology books about San Diego. I should get Fire Mountains and a good geology textbook at the book store. I am strongly considering entering the junior college and taking refresher courses on Geology. My wife suggest taking history, but my son says that I will get thrown out of class for being a smart ass.

As for the telescope, I haven't decided if I want a table model or a large model to roll out of the garage. Table model could be used on my balcony on our bedroom which faces north. I will keep in mind your excellent advice. I may revisit this in a few months.

[Kyle Holgate]

Many of the intrusions are determined to be plutons from the subduction of the oceanic crust, others smaller intrusions after the subduction stopped. The actual batholyths that are inland, pre-date the Jurassic period of sedimentation. Prior to 150 million years ago, most of San Diego was under deep ocean water and bordered the upthrust batholyth. Our geologic history really starts at this point.

I have two roadside geology books; one of Arizona and the other of Oregon. I also have three geology books about San Diego. I should get Fire Mountains and a good geology textbook at the book store. I am strongly considering entering the junior college and taking refresher courses on Geology. My wife suggest taking history, but my son says that I will get thrown out of class for being a smart ass.

As for the telescope, I haven't decided if I want a table model or a large model to roll out of the garage. Table model could be used on my balcony on our bedroom which faces north. I will keep in mind your excellent advice. I may revisit this in a few months.

Funny thing getting thrown out...
I took geology and history classes some time ago and at least for the history professor, I got a gem. There were many instances where I felt obliged to comment - and he was a very good sport about it PROVIDED I could back up my comment/remark with substantiated facts and/or was willing to debate my opinion at length. You know how much I hate debating:rolleyes:.
I think I still have my paper on the ME-262 somewhere. The arguement formed in class that the jet could have changed the course of the war in a big way. I argued that it was very unlikely. Professor said Ok, write it up! I did, got an extra cridit out of it and an A for the class overall.
My problem with Geology is my lack of skill with math. It wasn't great when I took the classes, it's much worse now!

[Kyle Holgate]

Ed, I live about 40 miles from St. Helens as the lava bomb flies (or more commonly ash cloud). I am 50 miles from Mt. Hood.
St. Helens has just recently been down-graded in threat level from Orange to yellow - it's just setting there steaming and puffing up its dome slowly - guess they're not concerned too much any more.
The amazing one to me is Rainier. What a monster! It may only be 3000 feet taller than Hood but it's huge in girth and looms over everything around it.

you can tell your kids that on a clear day on a nearby hilltop I can see 8 volcanoes high enough to have snow on them in July. Of course only one is active (tick, tick, tick) right now.

[john964]

Ed, I live about 40 miles from St. Helens as the lava bomb flies (or more commonly ash cloud). I am 50 miles from Mt. Hood.
St. Helens has just recently been down-graded in threat level from Orange to yellow - it's just setting there steaming and puffing up its dome slowly - guess they're not concerned too much any more.
The amazing one to me is Rainier. What a monster! It may only be 3000 feet taller than Hood but it's huge in girth and looms over everything around it.

you can tell your kids that on a clear day on a nearby hilltop I can see 8 volcanoes high enough to have snow on them in July. Of course only one is active (tick, tick, tick) right now.
A noteworthy percentage of the Cascades are active semi-active or dormant volcanos.

[Kyle Holgate]

The classification of volcanoes as active, dormant, extinct is tricky. Active is obvious, but there have been many times when an extinct volcano turned out to have some tricks to play still!

If you count all volcanic vents that have popped off in the last 10,000 years there are IIRC over 1000 volcanoes in OR. 10,000 years is along time for us puny mortals, but for geology it's a blink in time. Any number of these volcanoes could have something in store - well, except probably the cinder cones - they don't usually go off more than once.

[old_pop2000]

One of the issues with determining active, domant or extinct volcanoes is to determine their last eruption and that can be done with flora that might be trapped in lahars, ashflows or sometimes lava flows. Dendrochronology of trees in these kinds of flows, can be useful in determining their eruption date. Examining the strata above and below, using the law of superposition can give you approximate dates. If you can trace the vent or hot spot to other volcanoes in the direction of movement of the plate or plates, you can get some idea of whether the volcano is, in fact, extinct or just playing possum.

[Ed Rotondaro]

Ed, I live about 40 miles from St. Helens as the lava bomb flies (or more commonly ash cloud). I am 50 miles from Mt. Hood.
St. Helens has just recently been down-graded in threat level from Orange to yellow - it's just setting there steaming and puffing up its dome slowly - guess they're not concerned too much any more.
The amazing one to me is Rainier. What a monster! It may only be 3000 feet taller than Hood but it's huge in girth and looms over everything around it.

you can tell your kids that on a clear day on a nearby hilltop I can see 8 volcanoes high enough to have snow on them in July. Of course only one is active (tick, tick, tick) right now.

Kyle:

Thanks! My eldest son was mentioning to his brother that Alaska has the most active volcanoes in the US which led to the Mt. St. Helens question. He had questions about volcanic ash that I couldn't answer, like why does it form? I should send him to Wikipedia.

[Kyle Holgate]

How ash forms is a bit hard to describe. First, understand that water can be in liquid form even far above the boiling point of 212f (100c) as long as it's under pressure. The best anology is a soda bottle, as long as the cap is on, pressure is on - and you don't have bubbles fizzing. Take the top off, it fizzes.
Now if you have lots of water soaked into a substance like play dough and that dough is at 600 degrees under pressure - the water is still liquid and doesn't "fizz". Now take the pressure off. The water fizzes instantly to steam, the play dough can't expand to let it out so it explodes into little fragments.
Finally instead of play dough, make the stuff barely melted glass. When it explodes from the water in it turning to steam it makes billions of little glass particles. Ash. Almost all ash comes from volcanoes that have magma with lots of silica - and silica is pretty much what glass is made of.
So mix lots of water and other gasses into glass, put it in high pressure then suddenly take the pressure off. KaBOOM! Ash (and very nasty hot ash to boot).

[old_pop2000]

Here is information on ash, how it forms and pictures to help understanding of what Kyle explained. Which was on the mark. This just an aid.

http://pubs.usgs.gov/fs/fs027-00/

[Kyle Holgate]

Oregon's off shore subduction zone doing its thing... 5.0 inch quake off shore. Let's keep 'em small and off shore.

[clacton2]

Hi,
We actually had a noticeable earthquake in Britain last week, 5.2 on the Richter Scale, which is the biggest in the U.K. for 25 years. It shook both my dad's and my brothers houses, enough to wake them up, but no real damage apart from fallen chimney pots and a few roof tiles, but very unusual in this part of the world for one that big.
Jon:eek:

[old_pop2000]

Hi,
We actually had a noticeable earthquake in Britain last week, 5.2 on the Richter Scale, which is the biggest in the U.K. for 25 years. It shook both my dad's and my brothers houses, enough to wake them up, but no real damage apart from fallen chimney pots and a few roof tiles, but very unusual in this part of the world for one that big.
Jon:eek:
It can be disconcerting to most humans, if they have never experienced an earthquake. I've talked to people from the east, who would rather experience tornados and hurricane's than an earthquake. There is something about the movement of terra firma that scares people. Hurricanes and tornadoes are far more deadly, and pervasive than earthquakes.

[Kyle Holgate]

It can be disconcerting to most humans, if they have never experienced an earthquake. I've talked to people from the east, who would rather experience tornados and hurricane's than an earthquake. There is something about the movement of terra firma that scares people. Hurricanes and tornadoes are far more deadly, and pervasive than earthquakes.

I have to agree, there is something about the entire world moving by itself that really rattles you (pun intended) on a deep level the first time or two you feel a quake - even a little one. Personally, being interested in geology I am extremely aware now of even small movements, and find it surprising how often they happen - due to trucks and what not. Up here in OR - we get only a few a year typically unlike our neighboring states north and south - but we still get 'em. The number of known faults in the area is surprisingly large compared to the number of quakes - makes many wonder what we may be in for. Just look at the state of OR - why does the Columbia take that turn to the north then back to the west? There's a nice fault under the Willamette valley that runs up through Portland. So far, nothing from it in the hundred or so years we've been here. Still, obviously it's moved before!

I do agree with many though, you guys in the midwest can keep your severe thunderstorms and Tornadoes!

[clacton2]

It can be disconcerting to most humans, if they have never experienced an earthquake. I've talked to people from the east, who would rather experience tornados and hurricane's than an earthquake. There is something about the movement of terra firma that scares people. Hurricanes and tornadoes are far more deadly, and pervasive than earthquakes.

Yeah thats what they both said, it was definitely a first for them. I can quite believe what you say about hurricanes and tornadoes, Thank God, we don't generally get them here.
Jon:eek:

[Kyle Holgate]

Yeah thats what they both said, it was definitely a first for them. I can quite believe what you say about hurricanes and tornadoes, Thank God, we don't generally get them here.
Jon:eek:

And they say there is no such thing as monsters. What is a tornado if not a monster? yeah, maybe it doesn't think and directly go after people, but what consolation is that?
I'll stick with my once every 500 years subduction zone quakes and otherwise pretty benign weather!

[clacton2]

And they say there is no such thing as monsters. What is a tornado if not a monster? yeah, maybe it doesn't think and directly go after people, but what consolation is that?
I'll stick with my once every 500 years subduction zone quakes and otherwise pretty benign weather!


Hi,
I'm definitely with you on that one!!
Jon:D

[old_pop2000]

Hi,
I'm definitely with you on that one!!
Jon:D
FYI

The area east of San Diego from Palm Springs southward through Salton Sea to the Mexican border, about 80-90 miles from SD proper, has 2.0 to 3.0 earthquakes every week. We've had eleven earthquakes in the last 7 days, which is actually a low figure. We average one 4.0 to 5.0 a month. San Diego county has three active faults running through the middle of the city. The major one is the Rose Canyon. Our saving grace is that these are transform faults and usually don't generate earthquakes greater than a 7.0; little consolation, however. Most of use have enough drinking water stored for three days, batteries for flash lights, candles, canned food and other items like tents, coolers stored and protected. We have to take special precautions with our water heaters and solar tanks to have them bolted and strapped the wall beams to prevent them from tipping over. We also have special shutoff valves on the gas meters. This family also has enough firearms and ammunition to hold off any would-be looters. These are just some of the precautions we live with in Earthquake country.

On a lighter note, I have actually slept through a 4.5 event. I have never heard the last of that, from my little lady.

[Ed Rotondaro]

FYI

The area east of San Diego from Palm Springs southward through Salton Sea to the Mexican border, about 80-90 miles from SD proper, has 2.0 to 3.0 earthquakes every week. We've had eleven earthquakes in the last 7 days, which is actually a low figure. We average one 4.0 to 5.0 a month. San Diego county has three active faults running through the middle of the city. The major one is the Rose Canyon. Our saving grace is that these are transform faults and usually don't generate earthquakes greater than a 7.0; little consolation, however. Most of use have enough drinking water stored for three days, batteries for flash lights, candles, canned food and other items like tents, coolers stored and protected. We have to take special precautions with our water heaters and solar tanks to have them bolted and strapped the wall beams to prevent them from tipping over. We also have special shutoff valves on the gas meters. This family also has enough firearms and ammunition to hold off any would-be looters. These are just some of the precautions we live with in Earthquake country.



On a lighter note, I have actually slept through a 4.5 event. I have never heard the last of that, from my little lady.

Dennis:

I'll take my lousy North East winters and too brief springs and summers anyday over earthquakes.

[Kyle Holgate]

Dennis:

I'll take my lousy North East winters and too brief springs and summers anyday over earthquakes.

I'll stick where I am too. No Nor'easters at all (occasional norwester of sorts though, every dozen years or so). No quakes to speak of ('cept that monster every 500 years). Nice warm summers with cool evenings. Smart trees that don't spend 3 months growing leaves only to drop them again in fall.
Ed - where in New York do you live???

[clacton2]

Dennis:

I'll take my lousy North East winters and too brief springs and summers anyday over earthquakes.

Hi,
Well just heard we are going to have severe gales and floods in the U.K. over the coming couple of days according to the Met office. Not exactly hurricane or tornado force, but bad enough to cause damage and disruption in most of the country apparently.
Jon:eek:

[old_pop2000]

Hey Kyle:

Have you ever heard of an episodic tremor and slip event?

Read this:

http://geology.about.com/b/2008/03/06/slow-earthquake-begins-in-washington.htm

[Ed Rotondaro]

I'll stick where I am too. No Nor'easters at all (occasional norwester of sorts though, every dozen years or so). No quakes to speak of ('cept that monster every 500 years). Nice warm summers with cool evenings. Smart trees that don't spend 3 months growing leaves only to drop them again in fall.
Ed - where in New York do you live???


Kyle:

I live in the town of Clifton Park. It's about 15 miles north of Albany which is the capital city (and where I work). I'm about 17 miles south of Saratoga (where the race track is). Figure about 3 hours north of New York City. Lots of farm land, trees that drop leaves (mainly oaks) and history. Cold snowy winters, rainy springs, warm summers and cool autumns.

[john964]

Kyle:

I live in the town of Clifton Park. It's about 15 miles north of Albany which is the capital city (and where I work). I'm about 17 miles south of Saratoga (where the race track is). Figure about 3 hours north of New York City. Lots of farm land, trees that drop leaves (mainly oaks) and history. Cold snowy winters, rainy springs, warm summers and cool autumns.
My brother is a loud shout from you(so to speek) at Ft Drum.

[clacton2]

Hi,
Well just heard we are going to have severe gales and floods in the U.K. over the coming couple of days according to the Met office. Not exactly hurricane or tornado force, but bad enough to cause damage and disruption in most of the country apparently.
Jon:eek:


Hi,
Well the predicted storms are here and the U.K. is taking a bit of a battering, fortunately I live on the South East coast which appears to be getting off fairly lightly at the moment compared with other areas, although we have some disruption to transportation.
Jon:eek:

[Kyle Holgate]

Heh, well let's see. Where ARE the best/safest places on earth to live? I cannot speak as much for other countries having not spent time studying weather and geologya and what not there as much as the US - so please forgive me if I'm being US centric!

New England: Stable Geology (meaning anything damaging is few and far between). Fairly severe weather (Snow, damaging thunderstorms, humidity+heat, Storm systems such as Noreasters and occasional hurricanes.

Pacific Northwest: Less stable geologically, in that a person living an average life span will probably live through a potentially damaging earthquake at least once. Still - this isn't something that is an every decade thing, and in particular if you are in Oregon you just don't get them enough to pay much attention to. Weather - virtually no severe weather, big pacific wind/rain storms once every 10 years or so do damge. No humidity usually in hot weather so little heat stroke sorts of danger. Rain can get a bit dreary, but that's not life threatening.

Mid Atlantic - (DC, Virginia, Maryland, etc). Same as New England geologially. Worse weather wise with more severe weather and a higher odds of Hurricanes.

SE (Georgia, Florida, etc). Warm, muggy potentially dangerously warm summer temp's, hurricanes, fairly frequent severe storms + moderately common tornadoes. (N. Carolina has had some pretty bad quakes, but these are uncommon)

Gulf coast - same as above, more hurricanes.

Inland east - More severe storms and severe winters. Moderately common storms and tornadoes.

Inland SE (Tennessee, Kentucky, etc). New Madrid Fault. Odds are good that one could spend their life without a dangerous quake though. Weather is not so good - dangerous storms and tornadoes moderately common. Winter weather can get nasty.

Great Planes: Geologically pretty stable, weather anything but. Tornado country with frequent thunderstorms - many severe.

SW - Desert country, little rain but potentially dangerous high temperatures. Thunderstorms occasionally. Geologically fairly active but once again - average life could be spent without problems.

Southern CA - good weather with occasional pacific storms spicing things up. Dry + wind = fire danger. Geologically - good potential for damaging or dangerous.

Northern CA - pretty much like the Pacific NW - 'cept maybe the San Andreas increases the odds of a real rocker.

Rocky mt - Geologically moderate risks, weather wise moderately dangrous with thunderstorms fairly common

So - safest place - least likely to be killed from some natural disaster or weather related problem? I think Pacific NW is high though the quake risk is there. Weather risks seem to be more common elsewhere. No heat related problems, virtually no tornadoes, no hurricanes, no severe thunderstorms to speak of (maybe once every couple years).
Volcano pops once every 100 years -could make things very interesting very quickly at any time - but mostly they are just perty mountains.

[clacton2]

Hi,
Well the predicted storms are here and the U.K. is taking a bit of a battering, fortunately I live on the South East coast which appears to be getting off fairly lightly at the moment compared with other areas, although we have some disruption to transportation.
Jon:eek:

The storms are still raging in certain parts of the country, leading to all kinds of damage and disruption, but they are abating in our area, so fingers crossed we appear to have got away lightly.
Jon:D

[Ed Rotondaro]

My brother is a loud shout from you(so to speek) at Ft Drum.

John:

I visited Watertown once while working for the state of New York (proud home of Eliot Spitzer the newly disgraced governor). An old small city right in the snow belt (seriously they get at least 10 feet of snow each year). I assume your brother's in the 10th Mountain Division? It's about just under three hours from me.

[Ed Rotondaro]

Hi,
Well the predicted storms are here and the U.K. is taking a bit of a battering, fortunately I live on the South East coast which appears to be getting off fairly lightly at the moment compared with other areas, although we have some disruption to transportation.
Jon:eek:

Jon:

Guess the UK won't have any water worries this summer?

[Ed Rotondaro]

Heh, well let's see. Where ARE the best/safest places on earth to live? I cannot speak as much for other countries having not spent time studying weather and geologya and what not there as much as the US - so please forgive me if I'm being US centric!

New England: Stable Geology (meaning anything damaging is few and far between). Fairly severe weather (Snow, damaging thunderstorms, humidity+heat, Storm systems such as Noreasters and occasional hurricanes.

Pacific Northwest: Less stable geologically, in that a person living an average life span will probably live through a potentially damaging earthquake at least once. Still - this isn't something that is an every decade thing, and in particular if you are in Oregon you just don't get them enough to pay much attention to. Weather - virtually no severe weather, big pacific wind/rain storms once every 10 years or so do damge. No humidity usually in hot weather so little heat stroke sorts of danger. Rain can get a bit dreary, but that's not life threatening.

Mid Atlantic - (DC, Virginia, Maryland, etc). Same as New England geologially. Worse weather wise with more severe weather and a higher odds of Hurricanes.

SE (Georgia, Florida, etc). Warm, muggy potentially dangerously warm summer temp's, hurricanes, fairly frequent severe storms + moderately common tornadoes. (N. Carolina has had some pretty bad quakes, but these are uncommon)

Gulf coast - same as above, more hurricanes.

Inland east - More severe storms and severe winters. Moderately common storms and tornadoes.

Inland SE (Tennessee, Kentucky, etc). New Madrid Fault. Odds are good that one could spend their life without a dangerous quake though. Weather is not so good - dangerous storms and tornadoes moderately common. Winter weather can get nasty.

Great Planes: Geologically pretty stable, weather anything but. Tornado country with frequent thunderstorms - many severe.

SW - Desert country, little rain but potentially dangerous high temperatures. Thunderstorms occasionally. Geologically fairly active but once again - average life could be spent without problems.

Southern CA - good weather with occasional pacific storms spicing things up. Dry + wind = fire danger. Geologically - good potential for damaging or dangerous.

Northern CA - pretty much like the Pacific NW - 'cept maybe the San Andreas increases the odds of a real rocker.

Rocky mt - Geologically moderate risks, weather wise moderately dangrous with thunderstorms fairly common

So - safest place - least likely to be killed from some natural disaster or weather related problem? I think Pacific NW is high though the quake risk is there. Weather risks seem to be more common elsewhere. No heat related problems, virtually no tornadoes, no hurricanes, no severe thunderstorms to speak of (maybe once every couple years).
Volcano pops once every 100 years -could make things very interesting very quickly at any time - but mostly they are just perty mountains.

Kyle:

Generally good analysis. NYS where I live is actually considered a Mid-Atlantic state. Fairly stable regarding earthquakes, etc. Winter can be rough, but summers are generally good unless we get stuck with a stalled low front bringing the heat and humidity from where Chris lives LOL! We can occasionaly get a minor tornado, but the biggest problems are flooding in the river valleys and that happens to a degree every year. September can be perfect around here. As can mid-May thru early June. Viriginia is usely not classifed as a Mid-Atlantic state. They include, NY, Pennslyvania and New Jersey with maybe Delaware though in. VA is the south baby!

[Ed Rotondaro]

The storms are still raging in certain parts of the country, leading to all kinds of damage and disruption, but they are abating in our area, so fingers crossed we appear to have got away lightly.
Jon:D

Jon:

The last time that happened I recall that air traffic was severely disrupted. Heathrow was closed for several days. Are conditions that bad this time around? Stay well.

[old_pop2000]

Kyle:

Generally good analysis. NYS where I live is actually considered a Mid-Atlantic state. Fairly stable regarding earthquakes, etc. Winter can be rough, but summers are generally good unless we get stuck with a stalled low front bringing the heat and humidity from where Chris lives LOL! We can occasionaly get a minor tornado, but the biggest problems are flooding in the river valleys and that happens to a degree every year. September can be perfect around here. As can mid-May thru early June. Viriginia is usely not classifed as a Mid-Atlantic state. They include, NY, Pennslyvania and New Jersey with maybe Delaware though in. VA is the south baby!
Well, except for water issues and earthquakes, my home town was over 88 degrees yesterday and I've wearing my shorts and t-shirts for two weeks.

Is it still winter? :cool::D

[clacton2]

Jon:

The last time that happened I recall that air traffic was severely disrupted. Heathrow was closed for several days. Are conditions that bad this time around? Stay well.

Ed,
Not bad enough to close airports completely, but some flights being disrupted and some very scary pictures of pilots trying to land planes in crosswinds. Not for the faint-hearted!
Jon:eek:

[clacton2]

Jon:

Guess the UK won't have any water worries this summer?

Ed,
I would think not, but you never know for sure!
Our water companies seem to manage to lose water through leaking pipes almost as quickly as they can accummulate it. LOL
Jon:o

[john964]

Ed,
I would think not, but you never know for sure!
Our water companies seem to manage to lose water through leaking pipes almost as quickly as they can accummulate it. LOL
Jon:o

Probably because some of your infrastucture has been around since Elizibeth I.

[Ed Rotondaro]

Probably because some of your infrastucture has been around since Elizibeth I.

John:

Hey you got to respect the British love for history after all.:D

[clacton2]

Probably because some of your infrastucture has been around since Elizibeth I.

Hi,
And thats the modern stuff, you should see the older equipment that needs replacing as opposed to just repairing! LOL
Jon:D:D

[clacton2]

John:

Hey you got to respect the British love for history after all.:D

Ed,
We are what we are! LOL
Jon;)

[old_pop2000]

Interesting article from the Denver GSA Meeting on data about the San Andreas.

http://gsa.confex.com/gsa/2007AM/finalprogram/abstract_127342.htm

[Ed Rotondaro]

Ed,
We are what we are! LOL
Jon;)

Jon:

As Fleet says "Rule Britannia"! (Did I spell that correctly?):confused:

[clacton2]

Jon:

As Fleet says "Rule Britannia"! (Did I spell that correctly?):confused:

Ed,
Yes!
Jon:D

[Kyle Holgate]

Interesting article from the Denver GSA Meeting on data about the San Andreas.

http://gsa.confex.com/gsa/2007AM/finalprogram/abstract_127342.htm

Wow, an on topic post!

[old_pop2000]

Kyle, Mike:
The earth is rocking and rolling in your neck of the woods. 5.9 earthquake, 225 miles SW of Portland, off of the coast. Six miles down, that's shallow.
No tsunami warning,yet. Feel anything?

http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008pqa5.php

[Mike Malanaphy]

Kyle, Mike:
The earth is rocking and rolling in your neck of the woods. 5.9 earthquake, 225 miles SW of Portland, off of the coast. Six miles down, that's shallow.
No tsunami warning,yet. Feel anything?

http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2008pqa5.php

Hi Dennis,

Nope, slept right through tit...must have happened late as it wasn't in the papers. There was a story in the Oregonian earlier this week about our coast and tsunamis. They found evidence of tsumani damage well beyond teh high ground safe line given for Canon Beach. Comforting.

[old_pop2000]

Hi Dennis,

Nope, slept right through tit...must have happened late as it wasn't in the papers. There was a story in the Oregonian earlier this week about our coast and tsunamis. They found evidence of tsumani damage well beyond teh high ground safe line given for Canon Beach. Comforting.
Don't feel bad, I sleep through them all the time. And we get them weekly.

[Kyle Holgate]

Nothing here either. They are pretty common down there - one area of the faults that seems to actually move as opposed to further north where everything is nice and quiet. Quiet is good, right? :eek:

http://neic.usgs.gov/neis/bulletin/neic_pqa5_h.html

[old_pop2000]

Nothing here either. They are pretty common down there - one area of the faults that seems to actually move as opposed to further north where everything is nice and quiet. Quiet is good, right? :eek:

http://neic.usgs.gov/neis/bulletin/neic_pqa5_h.html
You can have all the earthquakes and Tsunami's after April 17-24, when we are on the Columbia River trip. None of that stuff while I am in the area, I have enough to contend with around here, thank you very much.

[Ed Rotondaro]

You can have all the earthquakes and Tsunami's after April 17-24, when we are on the Columbia River trip. None of that stuff while I am in the area, I have enough to contend with around here, thank you very much.

Dennis:

That'a all we would need, your cruise ship to get swamped by tsunami. Boy I am glad I live on the East coast. Crappy weather is better than geography that tries to kill ya.

[old_pop2000]

Dennis:

That'a all we would need, your cruise ship to get swamped by tsunami. Boy I am glad I live on the East coast. Crappy weather is better than geography that tries to kill ya.
Well, as long as the captain turns his bow towards the wave and battens down the hatches, everything will be fine.

Yea Right!!!!:rolleyes:

[Kyle Holgate]

A tsunami would not get all the way up the Columbia to Portland. I would be more interested in the "tsunami" generated by the failure of one or more of the dams on the river - the one heading down stream rapidly! I've often wondered how well built those dams are - built long before anyone realized there was a major quake threat in the region. On top of that - the Columbia has been around longer than virtually any geologic feature here - pre-dating the cascades, the flood basalts and the older yet west cascade mountain range of which little is left. If that river has managed to flow that long, I really wouldn't put my money on a few dams built by puny humans.

I can't remember exactly what the quote is or where it's from, but it goes something like this: Humans live at the suferage of nature, subject to change at any time without notice. We may notice the change just long enough to kiss our butts goodbye - or maybe not?

[john964]

Dennis:

That'a all we would need, your cruise ship to get swamped by tsunami. Boy I am glad I live on the East coast. Crappy weather is better than geography that tries to kill ya.

Acctually weather kills more people world wide than any other natural disaster.

[Kyle Holgate]

I expect that from the perspective of most people that are used to where they live, other places seem much more dangerous. In the Pacific NW for example - yes we have volcanoes and earthquakes but they are typically pretty inactive over the average life span of people. I've lived here 40 years now and had one major volcanic eruption that did kill people and 1 moderate earthquake that did damage but killed no one. I'd be far, far more nervous living further east where there are severe thunderstorms and possibly tornadoes. There are those living in the midwest thought that are used to them and wonder how we can live with earthquakes.

[old_pop2000]

Kyle:
On our trip, we are visiting the Columbia Gorge Discovery Center. I have the roadside book on Oregon you recommended. At the discovery center book store, is there one or two good books specifically on the cascade range volcanoes and geology you recommend.

Thanks

[Kyle Holgate]

http://www.space.com/scienceastronomy/080317-volcanic-mars.html

An update on the Volcanic past of Mars

[Kyle Holgate]

Kyle:
On our trip, we are visiting the Columbia Gorge Discovery Center. I have the roadside book on Oregon you recommended. At the discovery center book store, is there one or two good books specifically on the cascade range volcanoes and geology you recommend.

Thanks

http://www.amateurgeologist.com/products/cataclysms-on-the-columbia-a-laymans-guide-to-the-features-produced-by-the-catastrophic-bretz-floods-in-the-pacific-northwest-scenic-trips-to-the.html

And

http://geology.com/store/cascade-volcano.shtml

Those are the two that come immediately to mind. If I remember - when I get home next week I will look at my collection a bit and see what others I may recommend. The Cataclysm one doesn't deal specifically with the volcanoes of the cascades but instead covers the Missoula floods.
Fire moutains is a favorite of mine. Not only does it give lots of good scientific "meat" about the cascades and Mono lake but it also provides some of the native American legends and what not which I find interesting.
On your Columbia river trip you should get a good look at Mt. Hood, Mt. Adams and Mt. St. Helens. Unfortunately St. Helens isn't too interesting to see from the south - you'd have to find or make time to travel up to her north side to see the growing lava dome.
I say her - the legends refer to St. Helens as the female mountain over which Mt. Hood and Adams fought over. Now she's even going topless! Woohooo!

[Ed Rotondaro]

Acctually weather kills more people world wide than any other natural disaster.

John:

I'm not surprised by that. Mother Nature is a mean mother (don't talk like that Shaft! Showing my age here).

[old_pop2000]

http://www.amateurgeologist.com/products/cataclysms-on-the-columbia-a-laymans-guide-to-the-features-produced-by-the-catastrophic-bretz-floods-in-the-pacific-northwest-scenic-trips-to-the.html

And

http://geology.com/store/cascade-volcano.shtml

Those are the two that come immediately to mind. If I remember - when I get home next week I will look at my collection a bit and see what others I may recommend. The Cataclysm one doesn't deal specifically with the volcanoes of the cascades but instead covers the Missoula floods.
Fire moutains is a favorite of mine. Not only does it give lots of good scientific "meat" about the cascades and Mono lake but it also provides some of the native American legends and what not which I find interesting.
On your Columbia river trip you should get a good look at Mt. Hood, Mt. Adams and Mt. St. Helens. Unfortunately St. Helens isn't too interesting to see from the south - you'd have to find or make time to travel up to her north side to see the growing lava dome.
I say her - the legends refer to St. Helens as the female mountain over which Mt. Hood and Adams fought over. Now she's even going topless! Woohooo!
Sounds great, I will write those down.

Thanks

[Kyle Holgate]

Sounds great, I will write those down.

Thanks

It's too bad you can't get a quick side trip up to St. Helens in while your'e in the neighborhood. Weather is not likely to be very good in April -to see much though, but the blast zone and avalanch deposits are very interesting and very humbling - at least to mere mortal me. This was a little VEI 5 erutpion and the power was incredible. I can't help but look at the 3 Sisters area and wonder if a VEI 6 is brewing! South sister has been erupting Ryolite lately (well, 600 years lately). Ryolite is worth paying a bit of attention to.

[Kyle Holgate]

The ol' gal has finally taken a rest after several years of dome buiding. Funny how you can get used to an active and erupting volcano 40 miles away. Now that it's quit I kind of miss that little steam cloud.

[john964]

The ol' gal has finally taken a rest after several years of dome buiding. Funny how you can get used to an active and erupting volcano 40 miles away. Now that it's quit I kind of miss that little steam cloud.Lets hope we don't have a repete of 1980.

[Ed Rotondaro]

Lets hope we don't have a repete of 1980.

John:

Ain't that the truth. Nothing scarier than a powerful volcanic eruption except possibly a major earthquake.

[john964]

John:

Ain't that the truth. Nothing scarier than a powerful volcanic eruption except possibly a major earthquake.

In my life I have so far expereanced 4 earthquakes, 3 volcanic eruptions, 4 hurricanes, 2 cyclones, 3 typhoons.2 F2 and 1 F4 tornados and 1 firestorm.

[old_pop2000]

In my life I have so far expereanced 4 earthquakes, 3 volcanic eruptions, 4 hurricanes, 2 cyclones, 3 typhoons.2 F2 and 1 F4 tornados and 1 firestorm.
Hmm, never thought about myself. I've experienced more earthquakes than I can remember living in earthquake country and two firestorms. No Hurricanes, although Hurricane Camille in 1969 in the Gulf Coast missed me by a couple of weeks. No tornedoes but one A-bomb test. That was fun.

[john964]

Hmm, never thought about myself. I've experienced more earthquakes than I can remember living in earthquake country and two firestorms. No Hurricanes, although Hurricane Camille in 1969 in the Gulf Coast missed me by a couple of weeks. No tornedoes but one A-bomb test. That was fun.
The quakes were major ones 1 was the Northridge in LA one of the others happend in south central Idaho in the early 80's. I lived in Long Beach for 5 years when I was in the Navy. PS add one riot to that list.

[Ed Rotondaro]

In my life I have so far expereanced 4 earthquakes, 3 volcanic eruptions, 4 hurricanes, 2 cyclones, 3 typhoons.2 F2 and 1 F4 tornados and 1 firestorm.


John:

As I have said in the past, I'll take my frigid winters, lousy springs and variable autumns in the North East over that stuff anyday. Summer is good but shorter than I would like.

[Ed Rotondaro]

Hmm, never thought about myself. I've experienced more earthquakes than I can remember living in earthquake country and two firestorms. No Hurricanes, although Hurricane Camille in 1969 in the Gulf Coast missed me by a couple of weeks. No tornedoes but one A-bomb test. That was fun.

Dennis:

Only you and Chris would call an A-bomb test fun.:rolleyes:

[old_pop2000]

Dennis:

Only you and Chris would call an A-bomb test fun.:rolleyes:
Well, when you are nine years old, asleep in the back of the car, and its dark but then the whole sky lights up, you think that's fun. Plus it was July 4th. Mom had sparklers and I wanted to play with them when we got to the motel in Cedar City.

Interestingly, the AEC actually visited our motel room and tested us and checked us with geiger counters. Mom had to wash all the clothes, Dad washed the car. I remember white cards on the tables stating that this was a nuclear test, to clean everything. It was cool for me, not for my dad. This was the third bomb test he had been through. He was at Bikini in 1946. He took the scientist into the lagoon after both bombs. I have the script that was issued to the sailors for purchasing stuff. My dad managed to get signatures of the officers and scientist.

[john964]

John:

As I have said in the past, I'll take my frigid winters, lousy springs and variable autumns in the North East over that stuff anyday. Summer is good but shorter than I would like.

Ed, only the quake in S cent ID 2 valcanic booms and the firestorm were experenced localy the rest I had to travel to experence. All the Cyclones Hurricans and Typhoons were when I was in the Navy.

[Kyle Holgate]

Far be it for anyone on these forums to nit pick... BUT:
I question the firestrorms - that's something very, very few have ever lived through let alone even seen from a distance. Guess it depends on how you define them. The Media likes to call what happened down in San Diego last year a firestorm, but to my knowledge no "real" one developed - winds blowing into the inferno at near hurricane (or hurricane) speeds, etc.
I've read of the firestorm in Dresden and the ones in Japan during the war - huge monsters that have only been seen a few times since, in major forest fires where enough fuel is available to spawn them. I'll allow for "big fires" but take some convincing at firestorms! :D

Side-note: Fire science is very interesting. I studied it a bit wayyyy back out of high school. I imagine they know quite a bit more about it by now. If I ever win the Lotto I think I'd spend much of my life taking classes for no reason other than to learn more about stuff I find intersesting! I'd love to get back into more "heavier" geology. I just took the basic stuff in the local community college (and 20th century history, much to my professor's dismay at times!)

[old_pop2000]

Far be it for anyone on these forums to nit pick... BUT:
I question the firestrorms - that's something very, very few have ever lived through let alone even seen from a distance. Guess it depends on how you define them. The Media likes to call what happened down in San Diego last year a firestorm, but to my knowledge no "real" one developed - winds blowing into the inferno at near hurricane (or hurricane) speeds, etc.
I've read of the firestorm in Dresden and the ones in Japan during the war - huge monsters that have only been seen a few times since, in major forest fires where enough fuel is available to spawn them. I'll allow for "big fires" but take some convincing at firestorms! :D

Side-note: Fire science is very interesting. I studied it a bit wayyyy back out of high school. I imagine they know quite a bit more about it by now. If I ever win the Lotto I think I'd spend much of my life taking classes for no reason other than to learn more about stuff I find intersesting! I'd love to get back into more "heavier" geology. I just took the basic stuff in the local community college (and 20th century history, much to my professor's dismay at times!)
Well, the CDF called both, firestorms in many areas. The first conflagration was a firestorm. We had fire all around my area of lakeside, except for one direction. The flames and heat were sucking in air creating gale force winds around our house. The fires were creating their own wind, by the intense heat. That, to me was a firestorm.

Just for reference, the report for the 2003 fires was termed by the CDF in their report to the governor, "The Firestorm of 2003". All communiques on the two fires were termed "firestorm" by CDF and federal fire personnel.

Believe what you will, but, IMHO, it was a firestorm based on the definition given to me by a Federal Fire Chief of 40 years. My late father-in-Law who fought such fires.

[Kyle Holgate]

Well, the CDF called both, firestorms in many areas. The first conflagration was a firestorm. We had fire all around my area of lakeside, except for one direction. The flames and heat were sucking in air creating gale force winds around our house. The fires were creating their own wind, by the intense heat. That, to me was a firestorm.

Just for reference, the report for the 2003 fires was termed by the CDF in their report to the governor, "The Firestorm of 2003". All communiques on the two fires were termed "firestorm" by CDF and federal fire personnel.

Believe what you will, but, IMHO, it was a firestorm based on the definition given to me by a Federal Fire Chief of 40 years. My late father-in-Law who fought such fires.

Ok, ok ;) - it sounds like a firestorm if it's sucking in high velocity winds and making its own weather.
I still have a VEI index 5 volcanic eruption on my ticket. I have little desire to upstage that, though I admit a major eruption like Pinatubo would be fascinating (from upwind and a ways away). I fondly hope that the Juan De Fuca plate stays nice and fixed until after I kick off- then it can shake the $*#@ out of my bones all it wants, doubt I'll care!

[Ed Rotondaro]

Well, the CDF called both, firestorms in many areas. The first conflagration was a firestorm. We had fire all around my area of lakeside, except for one direction. The flames and heat were sucking in air creating gale force winds around our house. The fires were creating their own wind, by the intense heat. That, to me was a firestorm.

Just for reference, the report for the 2003 fires was termed by the CDF in their report to the governor, "The Firestorm of 2003". All communiques on the two fires were termed "firestorm" by CDF and federal fire personnel.

Believe what you will, but, IMHO, it was a firestorm based on the definition given to me by a Federal Fire Chief of 40 years. My late father-in-Law who fought such fires.

Dennis:

I had idea that the fires were that close to your house. Were you wetting it down to protect it? Scary stuff.

[old_pop2000]

Dennis:

I had idea that the fires were that close to your house. Were you wetting it down to protect it? Scary stuff.
We had ash all over the house and the surrounding area. We did have all water hoses hooked up and ready. I wet down some areas that were sort of dry. It was surreal. The sky had a red glow to it, and all around you, was fire except toward San Diego, westward. Everywhere else, North, East, South and a small amount westward, was fire. You could see flames shooting up all along the ridges. It was actually kinda kool, in a macabre sort of way.

[john964]

Far be it for anyone on these forums to nit pick... BUT:
I question the firestrorms - that's something very, very few have ever lived through let alone even seen from a distance. Guess it depends on how you define them. The Media likes to call what happened down in San Diego last year a firestorm, but to my knowledge no "real" one developed - winds blowing into the inferno at near hurricane (or hurricane) speeds, etc.
I've read of the firestorm in Dresden and the ones in Japan during the war - huge monsters that have only been seen a few times since, in major forest fires where enough fuel is available to spawn them. I'll allow for "big fires" but take some convincing at firestorms! :D

Side-note: Fire science is very interesting. I studied it a bit wayyyy back out of high school. I imagine they know quite a bit more about it by now. If I ever win the Lotto I think I'd spend much of my life taking classes for no reason other than to learn more about stuff I find intersesting! I'd love to get back into more "heavier" geology. I just took the basic stuff in the local community college (and 20th century history, much to my professor's dismay at times!)
I have seen the aftermath of a firestorm were absoultly nothing was left of a house including the foundation. I forgot that I was actully in 2 firestorms. The North Spokane County and Yellowstone Fires. The Spokane County was at the same time as the Oakland Hils Fire so you can guess what the media covered, we were also lucky that there were no deaths because most people living in the fires path listened to the timely evac orders and didn't wait tell the last second to get out. PS You can still see the path of the fire today almost 20 years later.

[old_pop2000]

I have seen the aftermath of a firestorm were absoultly nothing was left of a house including the foundation. I forgot that I was actully in 2 firestorms. The North Spokane County and Yellowstone Fires. The Spokane County was at the same time as the Oakland Hils Fire so you can guess what the media covered, we were also lucky that there were no deaths because most people living in the fires path listened to the timely evac orders and didn't wait tell the last second to get out. PS You can still see the path of the fire today almost 20 years later.
When I travel out to the gun range in a small town called Dulzura, we travel through the main area of the southern fires in San Diego last year. You can see the burnt brush and vegetation and the homes destroyed. When we turn off onto the dirt road leading to the range, on our left are two or three burnt out homes and ranches with people attempting to start rebuilding. And yes, you can see where the fire hit homes and how fickle it was, missing others.

[Kyle Holgate]

Portland has a range of 1000-1500 foot or so hills running along the western edge of the city (the West hills - go figure). They are both forested fairly heavily and where not choked with homes, mostly big nice ones with views of the Cascade mountains and the city. So far they are only occasionally hit with a mudslide here or there, nothing major. The main thing in my mind when looking at them is that they are not only clustered in very closely in a forested area, but they are east facing. Regardless of the myth, it gets very, very dry here sometimes and humidity can be very low - generally with a strong wind coming from the east.

I cringe looking up at those hills every summer. One fool with a barbaque or one cigarette in the wrong place and we're in for an Oakland hills type of disaster - or worse, since many of the outlets for the roads leading into the hills are to the east. There are few back ways in or out. A lot of people could get trapped up there with the fires racing up hill at them. Many of the roads are too narrow for firetrucks - to top it all off.

This is just one situation where people don't seem to care - it hasn't happened yet, after all. Afterwords there will be all kinds of finger pointing and law suits and what not. Funny how we sometimes are so into fire prevention, but other times have to wait until it happens THEN try to fix the problem(s).

[Ed Rotondaro]

Portland has a range of 1000-1500 foot or so hills running along the western edge of the city (the West hills - go figure). They are both forested fairly heavily and where not choked with homes, mostly big nice ones with views of the Cascade mountains and the city. So far they are only occasionally hit with a mudslide here or there, nothing major. The main thing in my mind when looking at them is that they are not only clustered in very closely in a forested area, but they are east facing. Regardless of the myth, it gets very, very dry here sometimes and humidity can be very low - generally with a strong wind coming from the east.

I cringe looking up at those hills every summer. One fool with a barbaque or one cigarette in the wrong place and we're in for an Oakland hills type of disaster - or worse, since many of the outlets for the roads leading into the hills are to the east. There are few back ways in or out. A lot of people could get trapped up there with the fires racing up hill at them. Many of the roads are too narrow for firetrucks - to top it all off.

This is just one situation where people don't seem to care - it hasn't happened yet, after all. Afterwords there will be all kinds of finger pointing and law suits and what not. Funny how we sometimes are so into fire prevention, but other times have to wait until it happens THEN try to fix the problem(s).

Kyle:

A friend of mine who lives outside of Portland has a sprinkler system that pumps water from I think the river. It can wet down his house and grounds in a few minutes. He got it primarily to protect against the fires that could occur.

[Kyle Holgate]

Kyle:

A friend of mine who lives outside of Portland has a sprinkler system that pumps water from I think the river. It can wet down his house and grounds in a few minutes. He got it primarily to protect against the fires that could occur.

Not a bad idea. The main things seem to be 1st - don't have flamable roofing tiles and 2nd, clear shrubs and vegitation from near your home. Firefighters have told people more than once around here that they'll concentrate on trying to save the homes that have gone to some effort to save themselves first. If you've insisted on cedar blank roofing and have landscaped with evergreens all around your home then forget it. If you've got ceramic tiles on the roof and have made an effort to keep your landscaping shurbs away from your home, then they will work with you in the event of a fire. It sounds a bit cold, but I do understand they can only do so much.

[old_pop2000]

I suppose that a link between the two fault zones is not surprising but here is a short piece on such a link:

http://www.sciencedaily.com/releases/2008/04/080403131923.htm

Also, here is a stop disaster game from the Seismological Society to have fun with and (dare I say it) learn something.

http://www.stopdisastersgame.org/en/

[john964]

Not a bad idea. The main things seem to be 1st - don't have flamable roofing tiles and 2nd, clear shrubs and vegitation from near your home. Firefighters have told people more than once around here that they'll concentrate on trying to save the homes that have gone to some effort to save themselves first. If you've insisted on cedar blank roofing and have landscaped with evergreens all around your home then forget it. If you've got ceramic tiles on the roof and have made an effort to keep your landscaping shurbs away from your home, then they will work with you in the event of a fire. It sounds a bit cold, but I do understand they can only do so much.

Kyle I remeber seeing a photo from the Oakland Hills fire were a guy had done all sorts of stuff to fireprof his home with some of the things you mentioned and IIRC he also had fire restant native plants and grasses. The photo showed that his house was the only one still standing for miles around.

[old_pop2000]

Kyle I remeber seeing a photo from the Oakland Hills fire were a guy had done all sorts of stuff to fireprof his home with some of the things you mentioned and IIRC he also had fire restant native plants and grasses. The photo showed that his house was the only one still standing for miles around.
One resident of San Diego lost two homes in a row in the recent firestorms. He is now rebuilding on the same spot....only underground. The whole house will be built below ground. I've really got to see how this idea works.

[Ed Rotondaro]

Kyle I remeber seeing a photo from the Oakland Hills fire were a guy had done all sorts of stuff to fireprof his home with some of the things you mentioned and IIRC he also had fire restant native plants and grasses. The photo showed that his house was the only one still standing for miles around.

John:

Sounds like he was smart. Here's hoping an earthquake doesn't nail him.

[Ed Rotondaro]

One resident of San Diego lost two homes in a row in the recent firestorms. He is now rebuilding on the same spot....only underground. The whole house will be built below ground. I've really got to see how this idea works.

Dennis:

Sorta like sod bustin' in the old days?

[old_pop2000]

Dennis:

Sorta like sod bustin' in the old days?
I wonder about building codes, which are strict in this area due to Earthquakes, on underground homes.

[Ed Rotondaro]

I wonder about building codes, which are strict in this area due to Earthquakes, on underground homes.

Dennis:

I would imagine that whoever is building the home would be cognizant of the requirements if only to get a building permit.

[old_pop2000]

Two articles on the geology of the mantle and the age of Grand Canyon


http://www.sciencedaily.com/releases/2008/04/080411092336.htm

http://www.sciencedaily.com/releases/2008/04/080410140455.htm

[old_pop2000]

Interesting piece on an unexpected earthquake swarm in the middle of the Juan De Fuca Plate.

http://www.sciencedaily.com/releases/2008/04/080413184801.htm

[Campy]

Nobody mentioned the Midwest earthquake today.

http://earthquake.usgs.gov/eqcenter/eqinthenews/2008/us2008qza6/

Frank

[Kyle Holgate]

Nobody mentioned the Midwest earthquake today.

http://earthquake.usgs.gov/eqcenter/eqinthenews/2008/us2008qza6/

Frank

I did note that there was a pretty big one out there. Probably it's a good thing as it may wake up some people to the threat of the New Madrid fault. We could use a good shake up here for that matter - the Cascadia subduction zone quake could happen any time and most people are very complacent. I have a water and food stash & first aid/survival kit in my car, but I should have more than that. It's hard to take it seriously even when you know it is and have seen the evidence of the last one with your own eyes (dead trees on the beach).

They sent a ship out to see if they can find the cause for the Pacific quakes that hit off Oregon last week - they think they may be due to an undersea volcanic eruption. It will be interesting to see what they find.

[Campy]

Whole lot of shakin' going on in Reno, NV.

http://www.seismo.unr.edu/

[old_pop2000]

Whole lot of shakin' going on in Reno, NV.

http://www.seismo.unr.edu/
They may get more earthquakes, possibly a swarm of over one hundred. I was stationed at Fallon. That swarm is west of Reno, along US Interstate 80 which goes up into the Sierra Nevada's through Donner Pass. I've been through that area, many times.

[Kyle Holgate]

I've been watching the us earthquake map for years now and I can say that I have never seen the west so active. There aren't very many big ones (big = 5 or higher to me) but there are just scads of little ones all over the map. Interesting and perhaps just a bit unsettling as I live right over the Juan de Fuca plate!

[old_pop2000]

Article on the possibility that large earthquakes cause smaller earthquakes around the earth.

http://www.sciencedaily.com/releases/2008/05/080525132352.htm

[djcyclone]

Nobody mentioned the Midwest earthquake today.

http://earthquake.usgs.gov/eqcenter/eqinthenews/2008/us2008qza6/

Frank



I felt that one. I woke up in the middle of the night and my bed was shaking. The only Earth Quake in Illinois that I know of happened when I was a kid. My Grandma told me about it. She was driving her car and noticed that the road was really bumpy. She was afraid she was going to lose control so she slowed down, but the car was still shaking violently. She stopped and that is when she noticed that it was an Earth Quake.

When I woke up I noticed that my bed was shaking, and I looked to see if my cat was scratching or something, but my cat was asleep on the pillow next to me. It stopped only about 30 seconds after it started, and I just went back to sleep thinking I had imagined the whole thing. I did not realize that it was an Earth Quake until I heard the radio talking about it the next morning. I forget what day that was, but it was about a month ago or so.

[djcyclone]

I did note that there was a pretty big one out there. Probably it's a good thing as it may wake up some people to the threat of the New Madrid fault. We could use a good shake up here for that matter - the Cascadia subduction zone quake could happen any time and most people are very complacent. I have a water and food stash & first aid/survival kit in my car, but I should have more than that. It's hard to take it seriously even when you know it is and have seen the evidence of the last one with your own eyes (dead trees on the beach).

They sent a ship out to see if they can find the cause for the Pacific quakes that hit off Oregon last week - they think they may be due to an undersea volcanic eruption. It will be interesting to see what they find.



There are alot of natural disasters that are predicted for the near future. The one that bothers me the most is Yellow Stone National Park. They say a Volcano is underneath it, and the park rises a couple of feet every year.:eek:

I watched a movie predicting what would happen in that event, and I do not know how accurate they where, but it was bad. An Even like that could bring the U.S. too its knees. I only hope I am not alive to see that happen.:(

[john964]

There are alot of natural disasters that are predicted for the near future. The one that bothers me the most is Yellow Stone National Park. They say a Volcano is underneath it, and the park rises a couple of feet every year.:eek:

I watched a movie predicting what would happen in that event, and I do not know how accurate they where, but it was bad. An Even like that could bring the U.S. too its knees. I only hope I am not alive to see that happen.:(
DJ, I hate to break it to you man but about 70% of Yellowstone NP is inside the caldera of a volcano.

The movie you saw was I belive Supervolcano and from what I understand it is a fairly accurate movie.

[Ed Rotondaro]

DJ, I hate to break it to you man but about 70% of Yellowstone NP is inside the caldera of a volcano.

The movie you saw was I belive Supervolcano and from what I understand it is a fairly accurate movie.

John:

Well I guess I'm not visiting Yellowstone anytime in the near future. I'll settle for lousy winters and cold springs in the great Northeast.

[djcyclone]

John:

Well I guess I'm not visiting Yellowstone anytime in the near future. I'll settle for lousy winters and cold springs in the great Northeast.


Just avoiding it will not help. Just pray that you are not alive when that happens. According to that movie, nearlly 1/3 of the U.S. will be directly affected by fall out and ash and stuff. The rest of the U.S. will get the side effects of it. It would put Helena too shame.

[old_pop2000]

There are alot of natural disasters that are predicted for the near future. The one that bothers me the most is Yellow Stone National Park. They say a Volcano is underneath it, and the park rises a couple of feet every year.:eek:

I watched a movie predicting what would happen in that event, and I do not know how accurate they where, but it was bad. An Even like that could bring the U.S. too its knees. I only hope I am not alive to see that happen.:(

According to a recent report by the USGS as of 2007:


Of all the eruptive hazards that might occur in the region of the Yellowstone NP, by far the least likely is that of another major caldera-forming pyroclastic eruption of 100 cubic kilometers or greater.

There have been three such massive caldera forming explosions in the last 2 million years, however, the chambers where the rhyolitic magma erupted from, have solidified. Bottom line is that there are more hazards due to hydrothermal eruptions, than magmatic pyroclastic eruptions within the basin. Relax, enjoy the park. It isn't going anywhere, anytime soon.;):D

http://pubs.usgs.gov/of/2007/1071/of2007-1071.pdf

[john964]

John:

Well I guess I'm not visiting Yellowstone anytime in the near future. I'll settle for lousy winters and cold springs in the great Northeast.
Ed, Besides Yellowstone there are 4 other National Parks that feature volcanos. They are Crater Lake NP Hawaii Volcano NP Mt Lassen NP Mt Rainier NP and there are also several other Nat Rec Areas that have volcanos like Mt Shasta and Mt Hood.

[Ed Rotondaro]

Ed, Besides Yellowstone there are 4 other National Parks that feature volcanos. They are Crater Lake NP Hawaii Volcano NP Mt Lassen NP Mt Rainier NP and there are also several other Nat Rec Areas that have volcanos like Mt Shasta and Mt Hood.

John:

I'll stick to Cape Cod and risk a shark attack. Anybody have anything new on the China earthquake? Man that was a really bad one.

[Kyle Holgate]

With volcanoes it's all what you're used to. I grew up and still live in western Oregon and rather like having the white capped sentinels standing on the horizon. Only St. Helens is no longer viewable from nearby where I'm at - since it lost 1,300 feet in 1980.

Ed, you are EAST of Yellowstone therefore downwind - I'll take where I am any day as the wind virtually never blows from Yellowstone my way!

Seriously the Yellowstone volcano is always up to something. We don't know much about it really - meaning what it takes for it to erupt - but there should be a lot of warning, meaning unusual activity before that happens - and right now there isn't anything weird going on.
Long Valley in Central/eastern CA is actually one more to be worried about than Yellowstone. It has been more active as far as ground swellings and such in some ways, and has put out more than enough ash to cause serious problems. It too is monitored though and isn't up to no good currently. I keep an eye on all the US volcanoes that have monitoring at least weekly, I'll let anyone know if it's time to put up an umbrella or run!

Here is a good website for keeping an eye on them worldwide - one of my favorite volcano sites. http://www.intlvrc.org/

[Ed Rotondaro]

With volcanoes it's all what you're used to. I grew up and still live in western Oregon and rather like having the white capped sentinels standing on the horizon. Only St. Helens is no longer viewable from nearby where I'm at - since it lost 1,300 feet in 1980.

Ed, you are EAST of Yellowstone therefore downwind - I'll take where I am any day as the wind virtually never blows from Yellowstone my way!

Seriously the Yellowstone volcano is always up to something. We don't know much about it really - meaning what it takes for it to erupt - but there should be a lot of warning, meaning unusual activity before that happens - and right now there isn't anything weird going on.
Long Valley in Central/eastern CA is actually one more to be worried about than Yellowstone. It has been more active as far as ground swellings and such in some ways, and has put out more than enough ash to cause serious problems. It too is monitored though and isn't up to no good currently. I keep an eye on all the US volcanoes that have monitoring at least weekly, I'll let anyone know if it's time to put up an umbrella or run!

Here is a good website for keeping an eye on them worldwide - one of my favorite volcano sites. http://www.intlvrc.org/

Kyle:

Thanks, my son will be interested in that site. It's scary to realize just how geologically active the world is. It's just a matter of time before a volcano goes off or the tectonic plates shift. Here's hoping that our prediction methods become more exact. Though one wonders even if we can predict the event, should we evacuate everybody? If so to where? And will we have enough time? Hell I'll settle for better tornado warnings. We think we own the Earth, but we just live here.

[Kyle Holgate]

Predicting that a volcano is more likely to erupt I believe we have down to a fairly good science. How big, exactly when - we don't. I know of no volcano that was being monitored that has erupted without showing signs that it was getting ready - seismographs, gas emissions, swelling, water table changes - all these or some of these have always shown indications in the past. This isn't saying one can't pop off without any warning, as most are not monitored very closely!

We live such short lives compared to geological time. Even if you're around 100 years you're probably not going to more than one cascade volcano erupting and may have perhaps 5 huge quakes somewhere on earth whil you're alive. Im 47 and we've had 3: Chile, Alaska and the Sumatran one a few years go.

I find it amusing how TV shows and news broadcasts and what not like to talk about the wrath of nature, or the wrath of Hurricane whatever. If nature EVER got mad at us we would be toast so fast we would hardly know what hit us! The problem is we like to think of ourselves as important and somehow just getting stepped on without any notice is insulting. Well, that's what nature does - just goes about it's routine and if humans are in the way, oops.

[djcyclone]

Just getting stepped on without notice???

The thing is, we almost always have notice, and we are just too stupid to realize it. Take New Orleanse for instance. How long have we known that it could be a problem? We still built a City there, and people still moved there making it one of the biggest and most populare cities in the U.S.

Most of the time we have plenty of notice, but we just like hope that we are wrong, and nothing will happen. Then something does happen, and everyone cries "why me." I have a DVD of a bunch of Comedians, and the one at the end makes jokes of how he often watches TV and just wished he could reach through the TV and slap people. He goes on to give an example.

(Victim)
"This is the 13th time the River has washed away every thing we own."

(News Reporter)
"So what are you going to do now"

(Victim)
"Well we're going to rebuild"

(Comedian)
Holding his hand back like he is going to hit the TV.
"I don't supose move is in your vocabulary?":D

[old_pop2000]

MSNBC article on a new dinosaur discovery in Utah


http://www.msnbc.msn.com/id/25209277/

[Ed Rotondaro]

MSNBC article on a new dinosaur discovery in Utah


http://www.msnbc.msn.com/id/25209277/

Dennis:

Very interesting that they found so much stuff in one area. The paleontologists will have a field day.

[djcyclone]

They are making predictions now that the Trex was actually a pack hunter. I have often wonderd such things, because it makes more sense for a hunter to operate in packs. Almost all of the animals today hunt in packs. The only large preditor that does not is a Great White Shark. Even the Great White has been known to hunt with other Great Whites, but it is vary rare. I cannot think of any other large preditors that hunt alone.

They are making this prediction, because they have found multiple sights where Trex remains are, and the sights always contain more than one Trex. Another thing they have always known, is that major herbdavores of that time would always form circles to protect their young. This means that any large preditor would have to operate in a pack in order to survive.

[old_pop2000]

They are making predictions now that the Trex was actually a pack hunter. I have often wonderd such things, because it makes more sense for a hunter to operate in packs. Almost all of the animals today hunt in packs. The only large preditor that does not is a Great White Shark. Even the Great White has been known to hunt with other Great Whites, but it is vary rare. I cannot think of any other large preditors that hunt alone.

They are making this prediction, because they have found multiple sights where Trex remains are, and the sights always contain more than one Trex. Another thing they have always known, is that major herbdavores of that time would always form circles to protect their young. This means that any large preditor would have to operate in a pack in order to survive.


I suspect our whole paradigm regarding predators in the age of Dinosaurs may have to be changed.

[Ed Rotondaro]

They are making predictions now that the Trex was actually a pack hunter. I have often wonderd such things, because it makes more sense for a hunter to operate in packs. Almost all of the animals today hunt in packs. The only large preditor that does not is a Great White Shark. Even the Great White has been known to hunt with other Great Whites, but it is vary rare. I cannot think of any other large preditors that hunt alone.

They are making this prediction, because they have found multiple sights where Trex remains are, and the sights always contain more than one Trex. Another thing they have always known, is that major herbdavores of that time would always form circles to protect their young. This means that any large preditor would have to operate in a pack in order to survive.

DJ:

Tigers hunt alone.

[old_pop2000]

DJ:

Tigers hunt alone.


Tigers, as with all cats, are solitary hunters between dusk and dawn. They are very territorial. As evidence by our cat, and his attitude toward the new cat next door.

However, dinosaurs are reptiles and I am not certain we can ascribe predator characteristics for felines to reptile. And, I am not that well versed in either. Need to research and get some books on the subject.

[Kyle Holgate]

Tigers, as with all cats, are solitary hunters between dusk and dawn. They are very territorial. As evidence by our cat, and his attitude toward the new cat next door.

However, dinosaurs are reptiles and I am not certain we can ascribe predator characteristics for felines to reptile. And, I am not that well versed in either. Need to research and get some books on the subject.

Evidence is mounting that Dinosaurs were not reptiles in the way we think of them today at least. Some or many of them may have been warm blooded entirely or be warm blooded when young and perhaps becoming more like today's cold blooded reptiles as they grew older. I am of the view that they were something unique with no modern equivalent. From what I have read it looks like juvenile T-rexes may have hunted in packs where older ones become more solitary and start doing more scavenging - chasing other animals from kills. The whole field is full of conflicting opinions and we really do have only a very, very small sample of bones and such to go by.

For modern major predators only the lions and canines are pack/pride hunters. Last I read there is a growing belief that great whites do form some sort of hunting groups, but they are virtually impossible to follow so we can't be sure. No reptile hunts in packs, thought the Komodo Dragons and croc's and such will gang up on a wounded animal and feed together on kills. Birds - except for crows and ravens which are omnivors - I cannot think of a predatory one that hunts in any kind of a pack/flock. They are the closest relative to the dinosaurs. If they DID hunt in packs - a flock of a few eagles could take down very large prey (shudder, ... the birds... shudder).

[djcyclone]

One thing about the TREX that has always bother me, is how the hell do we know it could only see things that moved? I mean that is a bit bold to make such a prediction. Obviously we have never seen a TREX in live action, so who had the gull to make that assesment?

[Kyle Holgate]

One thing about the TREX that has always bother me, is how the hell do we know it could only see things that moved? I mean that is a bit bold to make such a prediction. Obviously we have never seen a TREX in live action, so who had the gull to make that assesment?

I am pretty sure that is just a scene from Jurassic park for tension not something based on actual scientific theory. I am petty sure that the T-rex's brain has a very highly developed olfactory center (smell) and a much less developed visual cortex - but that doesn't mean it couldn't recongnize something that wasn't moving. Some reptiles and the like tend to be much less able to spot something keeping very still - and many animals have poor or no color vision which is one thing that helps us humans.
In any case in Jurrasic park - the T-rex has a nose! it sniffed the people, if it wanted them a real T-rex would have had no doubt they were there spotting them or not!

[old_pop2000]

http://news.yahoo.com/s/ap/20090202/ap_on_re_as/as_japan_volcano

[Mike D]

One thing about the TREX that has always bother me, is how the hell do we know it could only see things that moved? I mean that is a bit bold to make such a prediction. Obviously we have never seen a TREX in live action, so who had the gull to make that assesment?

Forgot about this thread, as I geologist I ought to be watching it.

Kyle is right but you asked how we know that. Well, its actually an educated WAG. There is a field called Comparative Paleontology, essentially comparing knowns to unknowns and hazarding a guess.

In the case of the TRex they used the size and shape of the brain, the shape of the cranial cavity, how the brain appears to connect to the spinal column, the impressions of the folds of the brain on the inside of the skull, the size and shape of the sinus cavity, the size and location of the eye sockets. Then they guess.

Here is an example; I find a skull that has very large eye sockets on the sides of its head, small sinus cavities, a large sagittal crest, a small brain cavity with most of the area of the brain at the back and bottom where the occipital and temporal lobes would be, little folding visible and a large area where the brain stem goes.

So here we go;


The large eye sockets on the side of the head tell me that it was likely nocturnal and a prey species. Big eyes to see better at night. Its a general rule of thumb that prey species, like horses and chickens, have eyes on the sides of their heads to increase their field of view and detect danger sooner while predators like dogs and raptors have eyes more towards the front of the head to provide a more focused field of view and much better depth perception.
Small sinuses lead me to believe that smell wasn't important, like cats who hunt by sight and sound vs. dogs who have large sinuses and hunt by smell.
Large sagittal crest tells me that it had very strong jaw muscles. Dogs and most predators have a distinct sagittal crest, the ridge that runs along the top of the skull.
Small brain, not very smart. Look at my sister.
Large brain areas in back. A larger area where the occipital lobe would go means lots of visual processing capacity which goes with the large eyes. The large area where the temporal lobe would be hints at memory capacity, auditory capacity and perception.The large brain stem area indicates a more primal and less developed nurological system where reactions tend to be more instinctive then learned. Common things in all prey species.

So here is my guess. It was a nocturnal prey species that relied on its eyesight and hearing and less on smell. It was an omnivore and/or a scavenger with a very strong bite. It wasn't any smarter then my sister.

Or I could be totally wrong. But its an educated guess based on comparison to existing and known structures and features.

I've intentionally left off the jaw and teeth, they are a whole area of study in and of itself.

So for the Trex they most likely looked at all the features of the skull and the brain and found current analogs and made the assumption that since the structures are similar then the function and capabilities would have been the same. But they might be wrong.

[Kyle Holgate]

Studies of the T-rex skull have shown that the olfactory (smelling) section of their brains were apparently pretty large. I think it's Jack Horner that thinks that is one clue to it's being a scavenger along with the small arms, small eyes and the indications that it wasn't that fast. All of these arguements can be countered, but who knows? I'd bet it was an opportunistic beast, if it could nab kills it would, but would it pass up live prey? Doubt it.
There was a show on National Geographic about the baby rexes. Young ones apparently start out fast moving with more steak knife like teeth then grow shorter legs and more spike like teeth as they age. I'd bet they may go for more ripping off (literally) other animals prey as they get older. Who'd mess with a full grown T-rex except perhaps another one?

[Christian Schwietzke]

Could T-Rex have been an opportunist? You know, the ones (like hyenas, I think? Or was that jackals?) who wait until a "real" predator killed something, then either scare the predator off, or dash in to grab something and be gone before the predator can react.
(by the way, from what I´ve read our own primate ancestors probably went through a phase like that, before they figured out how to do their own hunting)


And, just as a layman´s WAG, I would say that carnivores would not necessarily need to be able to see things that don´t move all that well - prey animals tend to move. Whereas herbivores would need to be able to see static things well, because both "prey" plants and stalking carnivores hardly move at all. And one of the rules of evolution is that unnecessary features do not develop, or recede once they are no longer needed (see flightless birds).

[Mike D]

Could T-Rex have been an opportunist? You know, the ones (like hyenas, I think? Or was that jackals?) who wait until a "real" predator killed something, then either scare the predator off, or dash in to grab something and be gone before the predator can react.
(by the way, from what I´ve read our own primate ancestors probably went through a phase like that, before they figured out how to do their own hunting)

Your on track with current thinking. Paleontologists now view the TRex as filling the same ecological niche as the alligator or crocodile. They eat anything and even kill if they have too. Being an opportunist = less energy expended per calorie and less risk of injury. But when a tender living morsel crosses your path you kill and eat.



And, just as a layman´s WAG, I would say that carnivores would not necessarily need to be able to see things that don´t move all that well - prey animals tend to move. Whereas herbivores would need to be able to see static things well, because both "prey" plants and stalking carnivores hardly move at all. And one of the rules of evolution is that unnecessary features do not develop, or recede once they are no longer needed (see flightless birds).

Again your in line with current thinking. The thought is that predators, flying birds and tree dwellers need the depth of field that you get with stereo vision. Also its believed that the brain does essentially a 'blink comparison' to catch minute movement and track prey/branches. Both require forward facing eyes. While herbivores/prey species spend most of their time with their faces in feed so eyes further back and side pointing give a wider field of view. They can still raise their head and point both eyes at something that bothers them to bet the depth of field and the 'blink comparison' capability. Plants don't run away much so herbivores use their smell and upper lip to decern food, and eyes for danger watch. Your dead on about the evolution and de-evolution of attributes. You can see this in the horse hoof over time. Of coarse this assumes you actually believe in evolution, but that's not topic for this forum. As an aside though, the world is a funny place, I had a paleontology professor that didn't believe in continental drift and he had a TA that was getting his masters in invertebrate paleontology that didn't believe in evolution and believed that the earth is 6000 years old. Talk about a dichotomy.

[old_pop2000]

... As an aside though, the world is a funny place, I had a paleontology professor that didn't believe in continental drift and he had a TA that was getting his masters in invertebrate paleontology that didn't believe in evolution and believed that the earth is 6000 years old. Talk about a dichotomy.

When I took Geology at San Diego State, we were discussing Wegener's theory of Continental Drift. The magnetic data from the MAD booms on the coast of Washington and the mid-Atlantic had not been analyzed completely. So, it was still a theory with a lack of data.

Yea, I know. I am old.

Now, I relate Trex to his future cousin-the bird. Some birds are predators, some are scavengers, some are both. If its dead, they will eat it. Animals are pragmatic like we humans.(Yeah right, Dennis) If they don't have to kill it, then so much the better. If I can run off the guy who killed it by roaring load, less work for me. I believe that the T rex was an opportunist, like the lion. It will kill if it has too, but it does not really have to run fast to do it. It uses stealth. ( Hard to think of 10 ton T rex moving stealthfully). Its great sense of smell and its vision are required by both scavenger and predator. I vote for an opportunist. The prey they were after probably were much slower. Fast is relative, you know.

[Kyle Holgate]

Some of the arguements that professional paleontologists make about the T-rex seem pretty stupid. One argument for example says that the T-rex front limbs are too short to be of any use such as to help it get up after a fall, so it must not run and risk falling.

Hmm, last I checked Ostriches, Emus, Rheas and Cassowaries - let alone turkeys and chickens don't have front limbs and they can run just fine (and fly in some cases). Also they don't need front legs to help feed, and all they have are beaks not a mouth full of huge teeth and the bite strength of a steam shovel!

My thinking is that the T-rex didn't need the front legs so like the eyes in cave fish, they start to "evolve" into nothing. We see some snakes with vestigial rear legs, I'd bet that a T-rex would have been without front legs entirely if it had had a few million more years.

The idea that the T-rexes change body forms so much as they grow is interesting. They appear to start out better designed to be active hunters and change into what looks more like something prone to scavenge. That may actually work - full grown T-rexes drive the smaller ones from their kills perhaps? Wonder if we'll ever know.

[Ed Rotondaro]

http://news.yahoo.com/s/ap/20090202/ap_on_re_as/as_japan_volcano

Dennis and Kyle:

An underwater volcano has erupted at Tongo in the Pacific. The pictures are pretty spectacular. But you guys are probably all over this one.

[old_pop2000]

Dennis and Kyle:

An underwater volcano has erupted at Tongo in the Pacific. The pictures are pretty spectacular. But you guys are probably all over this one.

That's been erupting for days, a boat load of scientist are on their way to observe. There is also an eruption in Colombia and Indonesia. The earth is a busy place.

I believe that the earthquake swarm in Yellowstone might be worrying people. I will have to go to the Yellowstone obervatory website. I believe Kyle monitors that closer than I.

[Ed Rotondaro]

That's been erupting for days, a boat load of scientist are on their way to observe. There is also an eruption in Colombia and Indonesia. The earth is a busy place.

I believe that the earthquake swarm in Yellowstone might be worrying people. I will have to go to the Yellowstone obervatory website. I believe Kyle monitors that closer than I.


Dennis:

I assume earthquake swarm denotes multiple earthquakes?

[old_pop2000]

Dennis:

I assume earthquake swarm denotes multiple earthquakes?

It does. But it depends on the source of the quakes. In Yellowstone, its magma on the move or heated water, putting pressure on the rocks. On the San Andreas or any fault system, it can be just the fault relieving some stress. If you relieve stress in one area, usually you increase the stress, somewhere else on the fault. Its like the domino effect. One section will move then another until you reach a section that is locked, the strain is increased. That is usually a spot to keep your eyes on.

[old_pop2000]

Apparently scientist are getting all worked up about our swarm of earthquakes we have been having. The swarm of earthquakes, still continuing, has been occurring on an area of the San Andreas termed the Brawley Seismic Zone near the communities of Bombay Beach and Brawley, California. The largest was the 4.7 but after that, we have been averaging about 3 to 6 earthquakes per day. Most in the range of 2.0 to 3.0, mostly 2.5-2.8. The region under scrutiny is on the eastern edge of the Salton Sea, for those of you who might want to look at it in Google earth. It is a right lateral fault about 45 km long. According to the USGS, we have had over 250 earthquakes in this swarm.

How far is this from my home? I know you are all worried, but the main focal point in Bombay Beach of the earthquakes is 79.63 miles from my home, exactly on a heading of 249 degrees. Yes, Ed, I did feel one of them yesterday about 1315 hrs. Nothing to panic over though.

Anyway, here is the article on what scientist are doing.

http://news.yahoo.com/s/ap/20090328/ap_on_re_us/sci_san_andreas_fault

[keschofield]

Apparently scientist are getting all worked up about our swarm of earthquakes we have been having. The swarm of earthquakes, still continuing, has been occurring on an area of the San Andreas termed the Brawley Seismic Zone near the communities of Bombay Beach and Brawley, California. The largest was the 4.7 but after that, we have been averaging about 3 to 6 earthquakes per day. Most in the range of 2.0 to 3.0, mostly 2.5-2.8. The region under scrutiny is on the eastern edge of the Salton Sea, for those of you who might want to look at it in Google earth. It is a right lateral fault about 45 km long. According to the USGS, we have had over 250 earthquakes in this swarm.

How far is this from my home? I know you are all worried, but the main focal point in Bombay Beach of the earthquakes is 79.63 miles from my home, exactly on a heading of 249 degrees. Yes, Ed, I did feel one of them yesterday about 1315 hrs. Nothing to panic over though.

Anyway, here is the article on what scientist are doing.

http://news.yahoo.com/s/ap/20090328/ap_on_re_us/sci_san_andreas_fault


Dennis,

In the sixties when I lived in San Jose and then Scotts Valley we used to get minor temblors every few weeks. We got used to them, but then I was a kid, and kids seem to get used to anything.

Is your situation similar to that or are the shocks you're getting worse?

[old_pop2000]

Dennis,

In the sixties when I lived in San Jose and then Scotts Valley we used to get minor temblors every few weeks. We got used to them, but then I was a kid, and kids seem to get used to anything.

Is your situation similar to that or are the shocks you're getting worse?

Kurt:
The swarm of earthquakes isn't really felt here in my hometown, they are too small. The real concern is that the Brawley Seismic Zone is under the Salton Sea, and there are no monitoring stations along most of its length, and geologist can't examine the fault zone, to see the historical seismicity of it. So, the answer is no, our situation is not the same. The concern is that this is a prelude to a larger earthquake since this portion of the San Andreas is locked.

[keschofield]

Kurt:
The swarm of earthquakes isn't really felt here in my hometown, they are too small. The real concern is that the Brawley Seismic Zone is under the Salton Sea, and there are no monitoring stations along most of its length, and geologist can't examine the fault zone, to see the historical seismicity of it. So, the answer is no, our situation is not the same. The concern is that this is a prelude to a larger earthquake since this portion of the San Andreas is locked.

The poor Salton Sea, that body of water has had more problems during my lifetime and before than any comparable body of water. It was in the headlines constantly during my years in California (1955-1968) and periodically since. Pictures of the old coastline and abandoned sites are haunting.

Good luck, stay safe, and watch for jets falling out of the sky. :rolleyes:

[old_pop2000]

The poor Salton Sea, that body of water has had more problems during my lifetime and before than any comparable body of water. It was in the headlines constantly during my years in California (1955-1968) and periodically since. Pictures of the old coastline and abandoned sites are haunting.

Good luck, stay safe, and watch for jets falling out of the sky. :rolleyes:

Oh yea, either the earth is shaking from natural forces or from aircraft falling from the skies. I will be vigilant, believe me. Thanks.

Just as a note: Salton Sea used to be a tourist area with camping zones around it. Now the water is partially contaminated and all those camping areas are gone. The pollution is from the farmers putting chemicals in the water and that drains into the sea. Plus, it is evaporating and is really salty now.

[Ed Rotondaro]

Oh yea, either the earth is shaking from natural forces or from aircraft falling from the skies. I will be vigilant, believe me. Thanks.

Just as a note: Salton Sea used to be a tourist area with camping zones around it. Now the water is partially contaminated and all those camping areas are gone. The pollution is from the farmers putting chemicals in the water and that drains into the sea. Plus, it is evaporating and is really salty now.

Dennis:

IIRC, National Geographic magazine had an article on the Salton Sea a few years back showing the effects. Rather stark to see what can happen.

[old_pop2000]

Dennis:

IIRC, National Geographic magazine had an article on the Salton Sea a few years back showing the effects. Rather stark to see what can happen.

Salton Sea, as it currently stands, was created in 1905 by a break in an irrigation canal on the Colorado River. Before the breach could be filled, the river flowed into the Salton Sea Basin. Historical evidence shows that the Colorado flowed into the basin from 1824 to 1904 about eight times. So the basin has been filled on numerous occasions.

As far as pollution, the water is tested twice a year by the State Water Resources Board. Apparently, they really haven't found much pollution, which is a surprise. But there are some other problems. The main pollutant is selenium which is elevated and accumulating. Apparenly it is naturally occurring in the Colorado.

If you are interested, here is my source website from the Salton Sea Authority.

http://www.saltonsea.ca.gov/thesea.htm

[Ed Rotondaro]

Salton Sea, as it currently stands, was created in 1905 by a break in an irrigation canal on the Colorado River. Before the breach could be filled, the river flowed into the Salton Sea Basin. Historical evidence shows that the Colorado flowed into the basin from 1824 to 1904 about eight times. So the basin has been filled on numerous occasions.

As far as pollution, the water is tested twice a year by the State Water Resources Board. Apparently, they really haven't found much pollution, which is a surprise. But there are some other problems. The main pollutant is selenium which is elevated and accumulating. Apparenly it is naturally occurring in the Colorado.

If you are interested, here is my source website from the Salton Sea Authority.

http://www.saltonsea.ca.gov/thesea.htm


Dennis:

My oldest son is very interested in both geology, vulcanism and the weather. If he has to do a book report for school, it is invariably on one of those topics. The other day he was debating with my wife about the proper terms regarding volcanoes. He contends that molten rock is magma and isn't lava until it actually spews out of a volcano. Is this true?

[Kyle Holgate]

Yep Ed, underground before it comes out of a volcano it is magma, after a volcano burps it up then it's lava. Even in Hawaii where it can head back underground for quite a distance inside a lava tube it's - well, Lava tube says it all.

[Kyle Holgate]

Every weekday or so I go to the web and see what quakes have occurred. In general, and it's far from scientific - California is more active than it has been, and not just down around the saltan sea. One thing that caught my eye is now the San Andreas fault is showing small quakes south and north of LA, but there is a big gap in the middle where little has happened. I wish I knew a Geologist I could BS with about stuff - there is a lot going on that doesn't make the news, but a geogeek like me would find very interesting!

Alaska is another spot - if you look at the activity along the subduction zone there (where the Pacific plate is scraping along below the continental plate) there are gaps where no quakes occur. I just hope they have good quake resistant structures up there, they're in for another "nice one" here on one of those gaps!

Then again - the entire west coast doesn't have quakes on the subduction zone. Is the entire thing locked? Theories abound and no one knows for sure.

[john964]

Yep Ed, underground before it comes out of a volcano it is magma, after a volcano burps it up then it's lava. Even in Hawaii where it can head back underground for quite a distance inside a lava tube it's - well, Lava tube says it all.
Trivia time, Where is the worlds longest Lava Tube Located?

[old_pop2000]

Trivia time, Where is the worlds longest Lava Tube Located?

Undara Volcanic in the national park in Queensland, Australia. One of them is 190 km. or 100 miles long. There is also Kazumura Cave in Hawaii, it is 40 miles long.

[Mike D]

Trivia time, Where is the worlds longest Lava Tube Located?

NE Australia somewhere.

Ed check out the USGS web site, they have some good material for kids.
http://education.usgs.gov/


Then again - the entire west coast doesn't have quakes on the subduction zone. Is the entire thing locked?Oh, thats the kind of statement that drives us geologists mad. Especially because its used by geologists that should know better. There is no such thing as a "locked" fault. In all geologic processes (volcanoes, faults, plate movement, etc.) it is either active, inactive or relic. And even these terms are somewhat nebulous because it all depends on the time scale. The San Andereas fault is an "active" fault. While it may only move every 10-20 years that is less then a second in geologic time. In geologic time continents are whizzing around and playfully bumping into each other like a preschool play time and mountians are jumping up and down to a disco beat. On a human scale nothing is happening.

[old_pop2000]

Every weekday or so I go to the web and see what quakes have occurred. In general, and it's far from scientific - California is more active than it has been, and not just down around the saltan sea. One thing that caught my eye is now the San Andreas fault is showing small quakes south and north of LA, but there is a big gap in the middle where little has happened. I wish I knew a Geologist I could BS with about stuff - there is a lot going on that doesn't make the news, but a geogeek like me would find very interesting!

Alaska is another spot - if you look at the activity along the subduction zone there (where the Pacific plate is scraping along below the continental plate) there are gaps where no quakes occur. I just hope they have good quake resistant structures up there, they're in for another "nice one" here on one of those gaps!

Then again - the entire west coast doesn't have quakes on the subduction zone. Is the entire thing locked? Theories abound and no one knows for sure.


There are a lot locked zones on the San Andreas. Most locked zones don't produce microquakes like the other areas. According to USGS, a study of 2594 microquakes at 515 repeater stations along a 110 mile segment, found periodic pulses of microquakes every three years on the northern half of the fault. The study found that quakes above 3.5 usually occurred, about one year after the microquakes started. As you say, they are still trying to understand the phenomenom. While the San Andreas is one of the most monitored and researched fault areas, it might be the least understood.

After the 1857 earthquake at Carrizo Plain that ruptured with 30 feet of lateral offset, that section has been locked. Populated areas of Antelope Valley, Southern San Joaquin and Los Angeles are definitely at risk. The Carrizo Plain quake was estimated at 8.0 and rupture about 220 miles of the fault.

[old_pop2000]

NE Australia somewhere.

Ed check out the USGS web site, they have some good material for kids.
http://education.usgs.gov/

Oh, thats the kind of statement that drives us geologists mad. Especially because its used by geologists that should know better. There is no such thing as a "locked" fault. In all geologic processes (volcanoes, faults, plate movement, etc.) it is either active, inactive or relic. And even these terms are somewhat nebulous because it all depends on the time scale. The San Andereas fault is an "active" fault. While it may only move every 10-20 years that is less then a second in geologic time. In geologic time continents are whizzing around and playfully bumping into each other like a preschool play time and mountians are jumping up and down to a disco beat. On a human scale nothing is happening.

It doesn't mean locked in the traditional sense. IIRC, it is a fault zone that is not slipping because of the resistance on the fault is greater than the shear stress across the fault. A fault in that condition has more strain built up that is eventually released in a large earthquake. The strain can be different types like elastic, ductile, brittle, but still very small changes in the length and volume. Things are still moving, but ever so slowly. From memory, that is best I can do.

The USGS has a good glossary and introductory information if anyone is interested.

[Kyle Holgate]

How about temporarily not slipping instead of locked? Jammed? That may work better than locked. For whatever reason it appears to be not moving, or at least no generating the typical small earthquakes that occur when a subduction zone is happily sliding along.

So either it's decided to stop moving for a short time (geologically speaking) it's stopped entirely (since nature wouldn't want to hurt Portland, Seattle, Vancouver BC and such) or it's sliding but not creating the usual quakes as subduction zone makes.

So much info that would be very interesting is not available to us armature Geologists. I'm just glad (well, until we HAVE the big one) I live here where I can head up to any one of a dozen volcanoes in a few hours driving and poke around at my leisure. Every year I wait for the snow to melt up there so I can go play Vulcanologist for another summer! Most of them are extinct of course, haven't had any activity in 4-600 years or so. That's a long time, after all (:rolleyes:)

[Mike D]

Doesn't locked simply mean that there have been no recorded microquakes or major quakes in that area for a period of time. It doesn't mean locked in the traditional sense. Some areas of faults, move easier due to the type of rocks in the area. I don't remember the minerals, but some are powdery and the plates just slip nicely others are not so nice. Those areas don't normally have microquakes. The fault is well over 800 miles long.

Actually Dennis you are using "locked" in the correct context. Zones can be locked but the fault as a whole is "active." But even that can be considered incorrect. This is where I hate science, terms carry ambiguity based on context. Especially geology. I've seen my structure prof go all read in the face when someone says something like "locked fault." There is an inherent imprecision to these terms. What does "locked' mean? Is it that a zone is static and not under stress or static but under constant stress or static and under increasing stress. Or does it mean that nothing is happening on a human time scale so it must be 'locked' or 'stuck' because we don't know what its doing.

I guess the important point to remember is that geologic processes are always active in general and in specific they are either active or inactive. Examples: the New Madrid fault in Missouri is considered an active fault zone but the last significant quake was in 1812, the Rio Grande Rift is considered an inactive rift/fault zone with the last significant fault movement about 28-30 million years ago. Through out the Basin and Range provenance in the US west there are "relict" faults that haven't had activity since their creation and show no surface feature and may even be deformed by later regional metamorphism.

So it would be accurate to say 'this area of the fault has been locked for the last 5 years.' But it would be inaccurate to say 'the San Andreas is locked.'

As far as mineral or crustal controls, that happens but the greatest effector is good old water. Water acts as both a lubricant and a solvent under pressure. This includes free water flowing in the ground and water locked up in the rocks and minerals. Hydrous (locked up water) rocks tend to be more plastic and deformable. Second is they type of fault (reverse, normal, thrust, dip-slip) and the axis of movement along that fault. Then you get structural elements, like the San Andreas north of LA takes a jog to the west. But the axis of movement is parallel to the fault so you get a jam up as the fault pushes against the offset. Here you could actually say that at that point the fault is temporally locked, until it slips, creates a new fault shearing off the obstruction, pushes the obstruction out of the way building a new set of coastal mountains in the process or becomes inactive and eventually becomes a relict fault.

[Ed Rotondaro]

Yep Ed, underground before it comes out of a volcano it is magma, after a volcano burps it up then it's lava. Even in Hawaii where it can head back underground for quite a distance inside a lava tube it's - well, Lava tube says it all.

Thanks Kyle. Now my wife will have to acknowledge her first born's volcano expertise.

[Ed Rotondaro]

Undara Volcanic in the national park in Queensland, Australia. One of them is 190 km. or 100 miles long. There is also Kazumura Cave in Hawaii, it is 40 miles long.

Dennis:

Figured you would know that!;)

[Ed Rotondaro]

NE Australia somewhere.

Ed check out the USGS web site, they have some good material for kids.
http://education.usgs.gov/

Oh, thats the kind of statement that drives us geologists mad. Especially because its used by geologists that should know better. There is no such thing as a "locked" fault. In all geologic processes (volcanoes, faults, plate movement, etc.) it is either active, inactive or relic. And even these terms are somewhat nebulous because it all depends on the time scale. The San Andereas fault is an "active" fault. While it may only move every 10-20 years that is less then a second in geologic time. In geologic time continents are whizzing around and playfully bumping into each other like a preschool play time and mountians are jumping up and down to a disco beat. On a human scale nothing is happening.

Mike:

Thanks, both my kids and me too will enjoy that site.

[Ed Rotondaro]

There are a lot locked zones on the San Andreas. Most locked zones don't produce microquakes like the other areas. According to USGS, a study of 2594 microquakes at 515 repeater stations along a 110 mile segment, found periodic pulses of microquakes every three years on the northern half of the fault. The study found that quakes above 3.5 usually occurred, about one year after the microquakes started. As you say, they are still trying to understand the phenomenom. While the San Andreas is one of the most monitored and researched fault areas, it might be the least understood.

After the 1857 earthquake at Carrizo Plain that ruptured with 30 feet of lateral offset, that section has been locked. Populated areas of Antelope Valley, Southern San Joaquin and Los Angeles are definitely at risk. The Carrizo Plain quake was estimated at 8.0 and rupture about 220 miles of the fault.

Dennis and Kyle:

Since we are talking about geological time here, is it possible for new faults to form and old faults to become more stable over say millions of years?

[old_pop2000]

Dennis and Kyle:

Since we are talking about geological time here, is it possible for new faults to form and old faults to become more stable over say millions of years?

It is entirely possible for faults to become dormant and others to appear. It depends on the source of the movement. Some rift zones are created, then stop. The new Madrid rift zone maybe that kind of area. Many earthquakes occur on long dormant fault zones or what geologist thought were dormant. I believe that that may have occurred in the UK in the Market Rason quake in 2008, IIRC. The UK sits on the interior of a plate, so real damaging earthquakes don't normally occur. Most damaging quakes occur at the fringes of the plates, like Indonesia, Japan, California, Washington, Alaska, Oregon, Turkey, Greece, Italy etc. All these places are on the fringes of plates.

[Ed Rotondaro]

It is entirely possible for faults to become dormant and others to appear. It depends on the source of the movement. Some rift zones are created, then stop. The new Madrid rift zone maybe that kind of area. Many earthquakes occur on long dormant fault zones or what geologist thought were dormant. I believe that that may have occurred in the UK in the Market Rason quake in 2008, IIRC. The UK sits on the interior of a plate, so real damaging earthquakes don't normally occur. Most damaging quakes occur at the fringes of the plates, like Indonesia, Japan, California, Washington, Alaska, Oregon, Turkey, Greece, Italy etc. All these places are on the fringes of plates.

Dennis:

Reminds me of an old joke I read as a kid regarding geological time:

First Guy: "Geologists think nothing of 1 million years."

Second Guy: "Great, I just loaned a geologist $100."

(I'll be here all week, try the veal!);)

[Mike D]

There is an excellent series of shows on volcanoes on the Science Channel. Its not heavy on the science but it is quite nice. Its back on on 4/13 and it runs from 6-11am called On the Volcanoes of the World.

[Kyle Holgate]

The series on the National Geographic channel called "How the Earth was made" is pretty good. I've spent enough time reading and watching the science shows that I don't learn anything new on many of them. On this one though, have learned quite a bit. Subjects covered so far: San Andreas fault, Loch Ness, Great Lakes, New York... seems like there were more but their subject escapes me. Nature (PBS) had a show on Kilauea volcano last night (around here) was interesting.

Side note - on the Nature special they mentioned that Yellow jackets have been introduced in Hawaii. :eek: Great, they are unpleasant little critters around here, can you imagine if they didn't die off each winter and just kept growing larger nests?!

[keschofield]

CNN news on the internet reported a 4.3 quake today centered 60 miles southeast of San Francisco. Did you feel it down your way Dennis? My guess would be that you did not, but stranger things have been known to occur.

[old_pop2000]

CNN news on the internet reported a 4.3 quake today centered 60 miles southeast of San Francisco. Did you feel it down your way Dennis? My guess would be that you did not, but stranger things have been known to occur.


No, Kurt, that is much too far away. It was a 4.3, 7.7 miles down. It was centered in the Morgan Hill area which is south of San Francisco, closer to Los Gatos and Gilroy. It might have been centered on Mt. Hamilton.

[old_pop2000]

The series on the National Geographic channel called "How the Earth was made" is pretty good. I've spent enough time reading and watching the science shows that I don't learn anything new on many of them. On this one though, have learned quite a bit. Subjects covered so far: San Andreas fault, Loch Ness, Great Lakes, New York... seems like there were more but their subject escapes me. Nature (PBS) had a show on Kilauea volcano last night (around here) was interesting.

Side note - on the Nature special they mentioned that Yellow jackets have been introduced in Hawaii. :eek: Great, they are unpleasant little critters around here, can you imagine if they didn't die off each winter and just kept growing larger nests?!


Both of those series are great. Especially the "How the earth was made".

[Kyle Holgate]

Just FYI - I know many if not most goers here have probably never experienced an earthquake so really don't know what the richter scale numbers mean with regards to what they would feel. Below is my experience, keeping in mind that quakes even of the same richter scale rating can behave a bit differently.

3.0 - nearby = stuff jiggles for a few seconds, feels about like a semi going by. About the time you notice something is going on, it stops. You wonder if it was your imagination or not until they mention it on the news.

4.3 - nearby = you have no doubt something is up. Stuff jiggles a bit, windows rattle, hanging plants or light fixtures sway for a bit after the quake is over. Personally I didn't find it alarming, but it was noticeable.

5.7 (70 miles away). 4-5 seconds of jiggling, windows rattled, bed jiggled like the cat was walking around on it. Cat wasn't in room.

6.8 (180 miles away, Nisqually quake near Seattle) - This one startled me. Things jiggled enough to certainly give no doubt it was a quake. I was... doing my business in restroom at the time. I remember zipping things up and thinking at least they'd find my body in a bit more dignified position if the building came down on me! This one had a noticeable rolling motion, like land waves. I was on the 2nd floor in a big building which may have amplified the motion. First quake I've encountered that I would have crawled under a desk or something if one were around.

[old_pop2000]

Just FYI - I know many if not most goers here have probably never experienced an earthquake so really don't know what the richter scale numbers mean with regards to what they would feel. Below is my experience, keeping in mind that quakes even of the same richter scale rating can behave a bit differently.

3.0 - nearby = stuff jiggles for a few seconds, feels about like a semi going by. About the time you notice something is going on, it stops. You wonder if it was your imagination or not until they mention it on the news.

4.3 - nearby = you have no doubt something is up. Stuff jiggles a bit, windows rattle, hanging plants or light fixtures sway for a bit after the quake is over. Personally I didn't find it alarming, but it was noticeable.

5.7 (70 miles away). 4-5 seconds of jiggling, windows rattled, bed jiggled like the cat was walking around on it. Cat wasn't in room.

6.8 (180 miles away, Nisqually quake near Seattle) - This one startled me. Things jiggled enough to certainly give no doubt it was a quake. I was... doing my business in restroom at the time. I remember zipping things up and thinking at least they'd find my body in a bit more dignified position if the building came down on me! This one had a noticeable rolling motion, like land waves. I was on the 2nd floor in a big building which may have amplified the motion. First quake I've encountered that I would have crawled under a desk or something if one were around.

Yea, that's about what I've felt. I had a '46 Chevy teardrop in high school, and I watched it go up and down during an earthquake. That was cool. At my first radar site, the USGS had a monitoring device across the San Andreas which went out to sea right at the site.

[keschofield]

No, Kurt, that is much too far away. It was a 4.3, 7.7 miles down. It was centered in the Morgan Hill area which is south of San Francisco, closer to Los Gatos and Gilroy. It might have been centered on Mt. Hamilton.

Thanks for the update. I know Morgan Hill and Los Gatos well from years ago. Guess the temblor shook up the onions in Gilroy! :D

[old_pop2000]

Thanks for the update. I know Morgan Hill and Los Gatos well from years ago. Guess the temblor shook up the onions in Gilroy! :D

They might have felt it, but I am certain San Jose felt it.

[john964]

Just FYI - I know many if not most goers here have probably never experienced an earthquake so really don't know what the richter scale numbers mean with regards to what they would feel. Below is my experience, keeping in mind that quakes even of the same richter scale rating can behave a bit differently.

3.0 - nearby = stuff jiggles for a few seconds, feels about like a semi going by. About the time you notice something is going on, it stops. You wonder if it was your imagination or not until they mention it on the news.

4.3 - nearby = you have no doubt something is up. Stuff jiggles a bit, windows rattle, hanging plants or light fixtures sway for a bit after the quake is over. Personally I didn't find it alarming, but it was noticeable.

5.7 (70 miles away). 4-5 seconds of jiggling, windows rattled, bed jiggled like the cat was walking around on it. Cat wasn't in room.

6.8 (180 miles away, Nisqually quake near Seattle) - This one startled me. Things jiggled enough to certainly give no doubt it was a quake. I was... doing my business in restroom at the time. I remember zipping things up and thinking at least they'd find my body in a bit more dignified position if the building came down on me! This one had a noticeable rolling motion, like land waves. I was on the 2nd floor in a big building which may have amplified the motion. First quake I've encountered that I would have crawled under a desk or something if one were around.I've felt a few quakes. My first was a 6.4 that was centered in south central Idaho 1981-82. I was in LA for the Northridge and Loma Priata quakes.

[Ed Rotondaro]

The series on the National Geographic channel called "How the Earth was made" is pretty good. I've spent enough time reading and watching the science shows that I don't learn anything new on many of them. On this one though, have learned quite a bit. Subjects covered so far: San Andreas fault, Loch Ness, Great Lakes, New York... seems like there were more but their subject escapes me. Nature (PBS) had a show on Kilauea volcano last night (around here) was interesting.

Side note - on the Nature special they mentioned that Yellow jackets have been introduced in Hawaii. :eek: Great, they are unpleasant little critters around here, can you imagine if they didn't die off each winter and just kept growing larger nests?!

Kyle:

Regarding Yellow Jackets, I agree. They love to build nests behind the shutters on the back of my house and they are very territorial. Last fall we noticed about a dozen of them in the room where we keep the PC. We figured they had gotten in thru a tear in the screen, but later found out they had gotten in thru our attic and made their way downstairs. Upon examing the attic we found a nest about three feet high covering a 2 by 4. When the extermniator came, he found that the nest was also under the flooring in the attic. It took him almost an hour to destroy it. He estimated that there were at least 10,000 insects and larvae. He took a 10lb bag of nest, and wasps out of the attic. Now I've got to make sure the opening is properly sealed so they don't try to come back in. I hate Yellow Jackets.:eek:

[Kyle Holgate]

Now imagine if that nest had been around for several years - 3,000 insects or more.

I am very tolerant of almost any critter. I've been an outdoorsy sort my whole life, and have the attitude that most of the time I am invading whatever the critter is's environment. I generally live and let live. Yellow jackets are an exception for sure. I can think of no critter I dislike more, that including mosquitoes. I have no problem with rattle snakes, black widows (one lived in my basement when I was a kid) or even hornets. Hornets mind their own business unless you $&*$ with their nest. Yellow jackets though, they are out looking for trouble whether you're near their nest or not.
We hates them my precious!

[Ed Rotondaro]

Now imagine if that nest had been around for several years - 3,000 insects or more.

I am very tolerant of almost any critter. I've been an outdoorsy sort my whole life, and have the attitude that most of the time I am invading whatever the critter is's environment. I generally live and let live. Yellow jackets are an exception for sure. I can think of no critter I dislike more, that including mosquitoes. I have no problem with rattle snakes, black widows (one lived in my basement when I was a kid) or even hornets. Hornets mind their own business unless you $&*$ with their nest. Yellow jackets though, they are out looking for trouble whether you're near their nest or not.
We hates them my precious!

Kyle:

That's absolutely right. Most bees and even wasps won't attack without a good reason, but Yellow Jackets are the punks of the bug always out to prove something. I try to eliminate any nests early in the spring before they start pestering me and the family on our deck.

[Kyle Holgate]

Kyle:

That's absolutely right. Most bees and even wasps won't attack without a good reason, but Yellow Jackets are the punks of the bug always out to prove something. I try to eliminate any nests early in the spring before they start pestering me and the family on our deck.

Every queen Yellow jacket you can kill in the spring when they come out of hibernation = potentially 1,000 or more workers not bugging you in the late summer.
One good thing about our hard freeze and snowy winter. Dang YJ's should be at a minumum.

[Ed Rotondaro]

Every queen Yellow jacket you can kill in the spring when they come out of hibernation = potentially 1,000 or more workers not bugging you in the late summer.
One good thing about our hard freeze and snowy winter. Dang YJ's should be at a minumum.

Kyle:

There are some specialized Yellow Jacket traps that you set out in the spring and bait with either meat or some sweet liquid. They work like lobster traps, the yellow jackets go in and they can't find their way out. Also the queen is usually the first out along with a handful of workers that survived the winter.

[old_pop2000]

A 6.2 earthquake struck a mountain town in Italy. It sits on a fault zone, but this is the worst. There have been at least four aftershocks in the 4.2-4.4 range. Looks like Africa just got a little closer to Europe.

http://www.cnn.com/2009/WORLD/europe/04/06/italy.quake/index.html?eref=rss_topstories

My Grandmother came from a little mountain town overlooking Bari, in the early part of century. Very picturesque, from what I gather.

[Ed Rotondaro]

A 6.2 earthquake struck a mountain town in Italy. It sits on a fault zone, but this is the worst. There have been at least four aftershocks in the 4.2-4.4 range. Looks like Africa just got a little closer to Europe.

http://www.cnn.com/2009/WORLD/europe/04/06/italy.quake/index.html?eref=rss_topstories

My Grandmother came from a little mountain town overlooking Bari, in the early part of century. Very picturesque, from what I gather.

Dennis:

The death toll is now 92 and they're still searching for trapped people. The town of L'Aquila was a beautiful mostly medieval town with lots of historic buildings. A typical hill town in the Abruzzi region located northeast of Rome. Thousands of people are homeless. Terrible shame.

[old_pop2000]

Apparently some historic buildings were damaged in the quakes.

http://www.msnbc.msn.com/id/30070969/from/RSS/

[Ed Rotondaro]

Apparently some historic buildings were damaged in the quakes.

http://www.msnbc.msn.com/id/30070969/from/RSS/

Dennis:

Bad, real bad. An earthquake makes bombing look like a slap on the wrist.

[old_pop2000]

Dennis:

Bad, real bad. An earthquake makes bombing look like a slap on the wrist.

Yea, Mother Nature and Bomber Harris have a lot in common; area bombing. Pick an area and wipe it out. ;)

[Ed Rotondaro]

Yea, Mother Nature and Bomber Harris have a lot in common; area bombing. Pick an area and wipe it out. ;)

Dennis:

Is there a way besides the Richter scale to measure the energy released in an earthquake? Is it kinetic energy?

[old_pop2000]

Dennis:

Is there a way besides the Richter scale to measure the energy released in an earthquake? Is it kinetic energy?

The Richter Scale is a quick, relatively accurate measurement of the power of the earthquake. The best is to go to site of the break, measure the fault's length, slip and depth to really get an accurate measure. The problem is that this takes weeks and months to find and cut into. There is a project at Princeton called the Centroid-Moment Tensor Project using computers to produce charts based on seismogram inversion. I don't know how accurate, but it is another method. There is also the Mercalli Scale which is no longer used.

[Kyle Holgate]

The scale really doesn't tell you a whole lot. You can have two quakes that have the same level on the richter scale but do different things to buildings, roads, etc. It is useful in a general way though in comparing one quake to another as far as energy output.
How close the epicenter is to the surface, what kind of fault it is, and of course the kind of structures we humans have built in the area all factor in.
There are different kinds of faults - some slip along horizontally (like the San Andreaus), others slip up and over or down and under (subduction zone for example). http://www.scienceclarified.com/landforms/images/ueol_02_img0052.jpg

Ground movement can be different depending on a lot of things. The modified Mercalli scale is probably a better way to guage an earthquakes impact on us puny humans than is the rictor scale.

http://en.wikipedia.org/wiki/Mercalli_intensity_scale

[Kyle Holgate]

I find it interesting, but have no idea of any significance it may have - that there is a big gap evident lately in California's common little quakes. Notice down by LA - you have plenty south, plenty north up the San Andreas - but nothing much in the middle. This has been going on (or not going on) for a while now.

http://earthquake.usgs.gov/eqcenter/recenteqsus/

[djcyclone]

Might be building up for the right moment :eek:.

[Ed Rotondaro]

The scale really doesn't tell you a whole lot. You can have two quakes that have the same level on the richter scale but do different things to buildings, roads, etc. It is useful in a general way though in comparing one quake to another as far as energy output.
How close the epicenter is to the surface, what kind of fault it is, and of course the kind of structures we humans have built in the area all factor in.
There are different kinds of faults - some slip along horizontally (like the San Andreaus), others slip up and over or down and under (subduction zone for example). http://www.scienceclarified.com/landforms/images/ueol_02_img0052.jpg

Ground movement can be different depending on a lot of things. The modified Mercalli scale is probably a better way to guage an earthquakes impact on us puny humans than is the rictor scale.

http://en.wikipedia.org/wiki/Mercalli_intensity_scale

Kyle and Dennis:

Thanks for the insights. But what actually is the energy released? Joules? Tons per square inch? Kilo tons? Just curious.

[old_pop2000]

Kyle and Dennis:

Thanks for the insights. But what actually is the energy released? Joules? Tons per square inch? Kilo tons? Just curious.


Total energy from an earthquake is rated in joules. Here is the USGS explanation.

http://www.usgs.gov/faq/list_faq_by_category/get_answer.asp?id=187

[Ed Rotondaro]

Total energy from an earthquake is rated in joules. Here is the USGS explanation.

http://www.usgs.gov/faq/list_faq_by_category/get_answer.asp?id=187

Dennis:

Thanks for the link!

[Mike D]

The Richter scale is a measure of the amplitude of the S-wave(shear/secondary/elastic shear wave). Basically its a measure of the up and down movements of the ground. This tends to miss a lot of the energy released so geologists are starting to use Joules and measure x-y-z axis movement for a sum of released energy. The problem is there isn't an accepted standard on how to do this yet. Also how do you compare that to the older Richter scale. While using Joules could give a more precise measure it introduces a huge data scale that in itself causes problems in ease of use. The Richter scale is logarithmic just like the decibel scale. That means that each point is 10 time larger then the last. So a 1 on the Richer scale is 10 time more powerful then a 0, a 2 is 10 times larger then a 1 and 100 times larger then a 0; a 3 is 10 times more then a 2, 100 times more then a 1 and 1000 times more then a 0. This makes the 6.7 North Ridge quake of 1992(?) about 5 million times a 0 and the 9.5 Valdivia quake in Chile in the early '60's 630 times greater then the North Ridge quake and 316 million times greater then a 0.

So while the Richter scale goes from 0-10 and encompasses a huge range to get the same range using Joules you would go from 4 Mega joules at 4.0x10^6 (4 with 6 0's)to 4 Zetta joules (yes there really is a zetta) at 4.0x10^21 (4 with 21 0's). A bit unwieldy. Back in the late Cold War days there was even a push to measure quakes in tons of TNT, just like nukes. So tons, kilo tons, mega tons of energy.

The problem is none of these take into account depth, distance from epicenter and more importantly geomorphology and soil types and depth. If you are on solid and hard rock like in Italy then all then energy is transmitted to the surface. If you are in the California central valley where there is several hundred feet of soil and unconsolidated sediment then some of the energy is absorbed by the ground. But if your on the Sacramento river delta or have a shallow water table then you can get liquefaction where the solid ground acts like water or quick sand. So a 4.0 quake in one place may be devastating but a 4.0 somewhere else would barely be noticeable.

Every system of measure has its flaws.

[old_pop2000]

The Richter scale is a measure of the amplitude of the S-wave(shear/secondary/elastic shear wave). Basically its a measure of the up and down movements of the ground. This tends to miss a lot of the energy released so geologists are starting to use Joules and measure x-y-z axis movement for a sum of released energy. The problem is there isn't an accepted standard on how to do this yet. Also how do you compare that to the older Richter scale. While using Joules could give a more precise measure it introduces a huge data scale that in itself causes problems in ease of use. The Richter scale is logarithmic just like the decibel scale. That means that each point is 10 time larger then the last. So a 1 on the Richer scale is 10 time more powerful then a 0, a 2 is 10 times larger then a 1 and 100 times larger then a 0; a 3 is 10 times more then a 2, 100 times more then a 1 and 1000 times more then a 0. This makes the 6.7 North Ridge quake of 1992(?) about 5 million times a 0 and the 9.5 Valdivia quake in Chile in the early '60's 630 times greater then the North Ridge quake and 316 million times greater then a 0.

So while the Richter scale goes from 0-10 and encompasses a huge range to get the same range using Joules you would go from 4 Mega joules at 4.0x10^6 (4 with 6 0's)to 4 Zetta joules (yes there really is a zetta) at 4.0x10^21 (4 with 21 0's). A bit unwieldy. Back in the late Cold War days there was even a push to measure quakes in tons of TNT, just like nukes. So tons, kilo tons, mega tons of energy.

The problem is none of these take into account depth, distance from epicenter and more importantly geomorphology and soil types and depth. If you are on solid and hard rock like in Italy then all then energy is transmitted to the surface. If you are in the California central valley where there is several hundred feet of soil and unconsolidated sediment then some of the energy is absorbed by the ground. But if your on the Sacramento river delta or have a shallow water table then you can get liquefaction where the solid ground acts like water or quick sand. So a 4.0 quake in one place may be devastating but a 4.0 somewhere else would barely be noticeable.

Every system of measure has its flaws.

Oh, I was hoping you were lurking in the shadows. Thanks. Curious, the P waves which hit first, are like sound waves-compression types. The S waves are like sine waves, vertically oriented. It would seem that solid rocks and liquid would propagate the P waves easily, but the S waves might be blocked by liquid. If I am correct, then, like sound waves in water, different rock types will propagate sound type waves easier. Is the analogy close?

[Ed Rotondaro]

Oh, I was hoping you were lurking in the shadows. Thanks. Curious, the P waves which hit first, are like sound waves-compression types. The S waves are like sine waves, vertically oriented. It would seem that solid rocks and liquid would propagate the P waves easily, but the S waves might be blocked by liquid. If I am correct, then, like sound waves in water, different rock types will propagate sound type waves easier. Is the analogy close?

Dennis and Mike:

Very interesting stuff. Thanks for the details.

[Mike D]

Oh, I was hoping you were lurking in the shadows. Thanks. Curious, the P waves which hit first, are like sound waves-compression types. The S waves are like sine waves, vertically oriented. It would seem that solid rocks and liquid would propagate the P waves easily, but the S waves might be blocked by liquid. If I am correct, then, like sound waves in water, different rock types will propagate sound type waves easier. Is the analogy close?


Spot on Dennis. P-waves are compression waves and act just like sound waves and they are attenuated but not blocked by low viscosity materials. This is why P-waves change directions through the earths inner core. P-waves tend also to be reflected and/or refracted through the interface between more viscous and less viscous material. If your familiar with Snells Law then that is the basic mechanism.

S-wave, being amplitude based, tend to be slower and of a lower frequency then P-waves. So they also are attenuated more by low viscosity fluids. S-waves are also affected by viscosity transitions like P-waves. So as a -wave moves from land to ocean the boundary would reflect part of the energy back into the rock and some would be refracted through into the water where it would get attenuated.

A fun way to show kids the difference is in the tub. Fill your tub full of water then take your hand stick it straight down in the water with your palm point towards the drain. Move your hand back and forth about 4 inches. The water starts rocking back and forth and eventually matches the movement of your hand. You'll even feel like the water is moving your hand. Now stop moving your hand but keep it in the water. The water will try to force your hand along with the movement of the water. Thats P-waves. When the sloshing water stops put your hand flat in the water. Sweep your hand up and down like a flipper. The water begins to get a sine wave motion but the motion keeps getting broken up by rebounding water from the ends and the sides. Now stop your hand but keep it in the water. You'll feal a slight force trying to move your hand but it dissapates fast. Thats S-waves. Now try to explain to your wife why there is water all over the bathroom.

[Kyle Holgate]

The first time I felt the different waves was back in what's called the Spring Break Quake way back in 1993 (seems like it wasn't that long ago!!!). It was at 5:34 am, I woke up wondering why then the quake rattled the window for a second or two. After that the bed rocked sideways for a bit then the quake stopped. There was a very distinct difference in the effects - one was rattling, one was rocking.

I still wonder why I woke up 10 seconds or so BEFORE anything happened.

The last quake I felt was the Nisqually quake in 2001 - that one just rocked the 2nd floor of the big Intel complex I was in at the time. I did not feel any different type of shaking. That one was enough to startle me, I have no desire to experience anything larger. I can't imagine shaking for 5 minutes or longer like happens in some of the big subduction zone quakes! If one hits while I'm still alive I hope I'm in the car on a clear stretch of road or out hiking or something... I can sit and bounce.

[Kyle Holgate]

Mike -
One thing I have wondered - The cascadia quake that is forecast to be on its way would have its center off the NW coast somewhere. If it's a 9.0 - what kind of attenuation would there be 100 miles away inland? I understand that it will vary due to what soils or rocks are under where I am - but in general do I expect damage to be about what a 7.0 would be for example?
I assume the ground movement would be attenuated by the distance.

[Mike D]

I still wonder why I woke up 10 seconds or so BEFORE anything happened.


There is actually a theory on this that I don't think has ever been tested. Subsonics. I've also read about atmospheric ionization but that sounds a bit weak to me.

[Ed Rotondaro]

The first time I felt the different waves was back in what's called the Spring Break Quake way back in 1993 (seems like it wasn't that long ago!!!). It was at 5:34 am, I woke up wondering why then the quake rattled the window for a second or two. After that the bed rocked sideways for a bit then the quake stopped. There was a very distinct difference in the effects - one was rattling, one was rocking.

I still wonder why I woke up 10 seconds or so BEFORE anything happened.

The last quake I felt was the Nisqually quake in 2001 - that one just rocked the 2nd floor of the big Intel complex I was in at the time. I did not feel any different type of shaking. That one was enough to startle me, I have no desire to experience anything larger. I can't imagine shaking for 5 minutes or longer like happens in some of the big subduction zone quakes! If one hits while I'm still alive I hope I'm in the car on a clear stretch of road or out hiking or something... I can sit and bounce.

Kyle:

We had a minor quake about three years ago in the spring. It was on a Saturday and I was sleeping in when suddenly it sounded like something was trying to scamper through the walls of our bedroom. My wife practically shrieked in fear, but I realized it was a quake. It lasted less than 30 seconds and the epicenter was up in the Adirondack mountains. There was no damage except to a couple of country rounds that had cracks in them. I believe it was about 5 on the Richter scale. You haven't lived until you've experienced a minor quake.

[Mike D]

Mike -
One thing I have wondered - The cascadia quake that is forecast to be on its way would have its center off the NW coast somewhere. If it's a 9.0 - what kind of attenuation would there be 100 miles away inland? I understand that it will vary due to what soils or rocks are under where I am - but in general do I expect damage to be about what a 7.0 would be for example?
I assume the ground movement would be attenuated by the distance.

You have just hit on the $64000 question. The NW coast is a kludge up, structural geologists just piddle themselves studying it. In northern Ca. and through the Washington coast you have ophiolite sequences, turbidites plutonic intrusions. Parallel to this you have the Cascades that are an uplifted granite pluton. Then another intermixed range, don't remember the name, that is volcanic. This this whole area is covered with ancient flood basalts and more recent eruption basalts and ash. Then this whole area is strewn with faults going every direction and even faults cross-cutting other faults. So your guess is as good as mine. I guess the answer is 'it depends.'

Here is my partly educated guess for a major quake, say 8.5+, off the Oregon coast.


Increased volcanic activity, ash burps, steam, hot springs.
Swarms of shallow small (2-3 Richter) quakes on coastal east-west faults.
Measurable vertical displacement in the coastal mountains.
Quake
Minor volcanic eruptions in near by volcanoes
Significant surface damage. Vertical and horizontal displacements, faults exposed on the surface parallel and perpendicular to the major fault.

I'm making some major assumptions here and I'm defining the trigger being volcanic instead of stress. The increase in activity of a near by magma chamber causing regional distortions, increased local heating, increased deep water flow(big trigger), etc. This tripping an already over stressed fault. There are 4-5 other just as likely trigger scenarios I can think of. But either way I think your looking at a lot of damage. There is a lot of hard rock in that area, a lot of faults large and small that can be sympathetically triggered. Lots of potential for large rock and even mountain slides, mud slides, dams breaking causing floods. The quake could even open up new paths for the magma chambers to vent causing flood basalts. Yeah, could be pretty nasty thinking about it.

Saying all this we have no bloody idea, its all just a WAG. As an example here at UT we have the Advanced Computing Center with the Ranger super computer. Last year I attended a presentation about visual modeling of quakes. Using known data they ran models of four different past quakes and three of the results pretty well fit what happened on the ground. But, when they modeled the 1949 Queen Charlotte quake it predicted several miles of displacement parallel to the fault and several hundred meters separation of the fault zone slipping part of the coast off towards the ocean. None of that happened.

WAG, at 100 miles inland your not going feel much of the direct effects of the quake. But, like a hurricane, its the secondary effects that'll be the worry. Floods, land slides, maybe volcanic activity, secondary faults releasing, power loss, fires, etc.

[keschofield]

I left California in 1968 when I was 13 years old.

Many, many years later when I was in my own house in Georgia (sometime between 1988 and 1999) I was half awakened by something, don't know what. Then suddenly the entire house shook like a giant terrier had it in its teeth and was shaking it. In my half awakened state my reaction was to call out to my mom and dad that we needed to get outside as if I were still at home in California. Then I finally remembered where I was and went to get my boys up. By then everything was over. The quake was a very small one and occurred at 5AM so most people slept through it. I was the only one in my house to feel it.

[old_pop2000]

The NW coast is a kludge up, structural geologists just piddle themselves studying it. In northern Ca. and through the Washington coast you have ophiolite sequences, turbidites plutonic intrusions. Parallel to this you have the Cascades that are an uplifted granite pluton. Then another intermixed range, don't remember the name, that is volcanic. This this whole area is covered with ancient flood basalts and more recent eruption basalts and ash. Then this whole area is strewn with faults going every direction and even faults cross-cutting other faults. So your guess is as good as mine. I guess the answer is 'it depends.'

....

So, the NW has a rock cycle normally found at the edge of spreading zones caused by the upwelling of magma from below. This would be the Ophiolite Sequence. What kinds of rocks in the sequence, limestones, basalt maybe. Correct?

If I remember my oceanography, turbidites derive from turbidity currents off of the shelf. These would be fine grained sediments found in deep oceans. currents like this carry a high density of fine grained sands and deposits off of the shelf due to erosion and seismic instability. Submarine trench slopes are great spots for turbidity currents. Whew! I don't think my oceanography is up to any more than that.

[old_pop2000]

I've read some studies about P wave velocity reduction in rocks and the number of joints seems to have a direct bearing on the reduction value of the wave propagation. It's an inverse relationship. The more joints in the rocks, the slower the wave moves. Test were completed on rocks by using sound compression waves. Rock types, porosity, water content, temperature etc. are all factors of varying degree.

[Mike D]

So, the NW has a rock cycle normally found at the edge of spreading zones caused by the upwelling of magma from below. This would be the Ophiolite Sequence. What kinds of rocks in the sequence, limestones, basalt maybe. Correct?

If I remember my oceanography, turbidites derive from turbidity currents off of the shelf. These would be fine grained sediments found in deep oceans. currents like this carry a high density of fine grained sands and deposits off of the shelf due to erosion and seismic instability. Submarine trench slopes are great spots for turbidity currents. Whew! I don't think my oceanography is up to any more than that.

Boy you have done your reading Dennis.

There is a specific idealized ophiolite rock sequence, from bottom to top; Olivine specifically perdotites (I love these, they are so cool looking under a polarizing scope (http://www.microscopy-uk.org.uk/mag/imgoct04/dwoucretards.jpg) or hand sample (http://www.sikhnet.com/files/news/2008/November/peridotite-HI.jpg) or crystalline (http://www.mindat.org/gallery.php?min=7710) and in my aquarium), then Gabros, then basalt sheet dikes then pillow lavas commonly at the base of pillow lavas are columnar basalts like make up the Devils Causeway with obsidian at the top of the layer then clastic sedimentary rocks on the very top, commonly turbidites.

You are exactly right on what turbidites are. Essentially a underwater silt/mud/rock avalanche that can cover hundreds of square miles. The think is that thanks to the water as a medium it causes a specific type of sorting of the material to happen both vertically and horizontally called a Bouma sequence. The basis of the Bouma or turbidite sequence is whats called 'fining upwards', in other words you have coarse material on the bottom, like gravel or even cobble conglomerates, and the material gets finer as you go up ending with very fine silt or clay on the top. Which is the opposite of most clastic deposits, like a river delta, that gets coarser as you go up. Here (http://serc.carleton.edu/NAGTWorkshops/sedimentary/visualizations/turbid.html) are some neat turbidite simulation videos and even a sand volcano!

[old_pop2000]

Boy you have done your reading Dennis.

There is a specific idealized ophiolite rock sequence, from bottom to top; Olivine specifically perdotites (I love these, they are so cool looking under a polarizing scope (http://www.microscopy-uk.org.uk/mag/imgoct04/dwoucretards.jpg) or hand sample (http://www.sikhnet.com/files/news/2008/November/peridotite-HI.jpg) or crystalline (http://www.mindat.org/gallery.php?min=7710) and in my aquarium), then Gabros, then basalt sheet dikes then pillow lavas commonly at the base of pillow lavas are columnar basalts like make up the Devils Causeway with obsidian at the top of the layer then clastic sedimentary rocks on the very top, commonly turbidites.

You are exactly right on what turbidites are. Essentially a underwater silt/mud/rock avalanche that can cover hundreds of square miles. The think is that thanks to the water as a medium it causes a specific type of sorting of the material to happen both vertically and horizontally called a Bouma sequence. The basis of the Bouma or turbidite sequence is whats called 'fining upwards', in other words you have coarse material on the bottom, like gravel or even cobble conglomerates, and the material gets finer as you go up ending with very fine silt or clay on the top. Which is the opposite of most clastic deposits, like a river delta, that gets coarser as you go up. Here (http://serc.carleton.edu/NAGTWorkshops/sedimentary/visualizations/turbid.html) are some neat turbidite simulation videos and even a sand volcano!

Ok, that's great. So turbidites are the opposite of what we usually see. In the turbidites, we see a sorting of smaller particles like a sieve, where the finer stuff stays on top. In river deposits, like you indicated, it works the opposite. So, can geologist use the presence of these turbidites to develop a timeline of seismic activity by measuring the thickness of the layers and the types of materials?

BTW, thanks for the vids. Man, am I going to have fun with all this.

[Mike D]

Ok, that's great. So turbidites are the opposite of what we usually see. In the turbidites, we see a sorting of smaller particles like a sieve, where the finer stuff stays on top. In river deposits, like you indicated, it works the opposite. So, can geologist use the presence of these turbidites to develop a timeline of seismic activity by measuring the thickness of the layers and the types of materials?

BTW, thanks for the vids. Man, am I going to have fun with all this.

Damn Dennis, your good. You just gave me a question I can't answer. Let me think on this one.... Interesting idea.

[Ed Rotondaro]

Boy you have done your reading Dennis.

There is a specific idealized ophiolite rock sequence, from bottom to top; Olivine specifically perdotites (I love these, they are so cool looking under a polarizing scope (http://www.microscopy-uk.org.uk/mag/imgoct04/dwoucretards.jpg) or hand sample (http://www.sikhnet.com/files/news/2008/November/peridotite-HI.jpg) or crystalline (http://www.mindat.org/gallery.php?min=7710) and in my aquarium), then Gabros, then basalt sheet dikes then pillow lavas commonly at the base of pillow lavas are columnar basalts like make up the Devils Causeway with obsidian at the top of the layer then clastic sedimentary rocks on the very top, commonly turbidites.

You are exactly right on what turbidites are. Essentially a underwater silt/mud/rock avalanche that can cover hundreds of square miles. The think is that thanks to the water as a medium it causes a specific type of sorting of the material to happen both vertically and horizontally called a Bouma sequence. The basis of the Bouma or turbidite sequence is whats called 'fining upwards', in other words you have coarse material on the bottom, like gravel or even cobble conglomerates, and the material gets finer as you go up ending with very fine silt or clay on the top. Which is the opposite of most clastic deposits, like a river delta, that gets coarser as you go up. Here (http://serc.carleton.edu/NAGTWorkshops/sedimentary/visualizations/turbid.html) are some neat turbidite simulation videos and even a sand volcano!

Mike:

Pretty cool stuff, my sons like to collect geodes and other stones. They'll get a kick out of this.

[Kyle Holgate]

The sequence of volcanic events in the NW - the west Cascades started up around 40 million years ago then quit for unknown reasons about the time the flood basalts started at around 17 m years ago. This went on for 5 m years or so then IT quit. Sometime about this time the modern Cascade range "lit up" and has been going ever since, though many think it's mostly at the end of its lifespan. There are no really young volcanoes except Mt. St. Helens - the rest are old and eroded for the most part (though potentially still quite potent if they wake up!).

The whole are is a mismash (now there is a geologic term ;)) of basalt, sedimentary rock scraped off the Juan de Fuca plate and local basalt flows topped off with missoula flood deposits. Portland felt the Nisqually quake (120 miles north) as about what you'd get with a "4.0" nearby. That one was a 6.8 centered 32 miles down so that may have helped it be felt over a wide area. If the entire Cascadia zone "unzips" estimates are it may be a 9.0. Portland is 100 (ish) miles from where this quake is likely to be. Should be 'fun'.

[old_pop2000]

My scope is a 4.5" rich field reflector scope. Look at Edmund scientific - Astorscan - that's what I have! I like it, I can bang it up a bit and it's extremely easy to just toss in the car and go. I miss having an equatorial mount and finder scope and more light gathering ability (used to have a celestron 8") but at least I can actually move this around and use it.

I have been seriously thinking about getting starry night, but I hate that you can't "test drive" software and send it back if you don't like it. Then again if you like it, I probably would too - I we have similar interests.

Yeah, England. One of the oldest areas still on the surface of the planet - and even they get to boogy on occasion! What I've been wondering is why Iceland has been so quiet for so long. Seems like they're due for an eruption of there (or past due).

Kyle:
So, is the current scenario that a 9.0 earthquake on the Juan De fuca begins or triggers eruptions of the volcano's along the NW. Those eruptions and release of gasses causes the whole Cascadia seismic zone to unzip and then more large earthquakes and Tsunami's? Has this type of scenario or similar actually occurred in the geologic record?

[Mike D]

The whole are is a mismash (now there is a geologic term ;))

Actually the technical term is 'melange'. :rolleyes:

[Kyle Holgate]

Kyle:
So, is the current scenario that a 9.0 earthquake on the Juan De fuca begins or triggers eruptions of the volcano's along the NW. Those eruptions and release of gasses causes the whole Cascadia seismic zone to unzip and then more large earthquakes and Tsunami's? Has this type of scenario or similar actually occurred in the geologic record?

Obviously Mike will likely know more on this than I, but living here and being interested in the subject I've tried to learn what I can about it. Dating the quake events isn't too difficult as radio-carbon dating works on the organic debris that are deposited and buried when the coastal tsunamis hit. Dating the volcanic activity isn't so easy, so tying the two together hasn't been done to my knowledge.
The last major cascadia quake was in January 26th of 1700 at about 9pm. Records show that the cascades were more active after that then they are currently, with documented activity on Mt. Baker, Glacier Peak, Mt. Rainier, Mt. St. Helens, Mt. Hood, Mt Shasta and Mt. Lassen all happening around 1700-1800 "ish". Which came first - the activity or the quake though?
There is little doubt that the cascadia subduction zone is the driving force for the volcanoes, but I've not seen any articles or papers discussing whether the volcanoes themselves have any effect on the zone.
Sure seems like things are quiet in the Cascades though compared to 200-300 years ago. That would top things off nicely, big quake then a few of the mountains "pop".

I don't necessarily want the mountains to erupt, but I make a yearly trek to Mt. Hood (at least one) and jump up and down on the south side. Sooner or later he's gonna go off, and the sooner it happens the fewer homes and businesses will be effected since they keep building up there. It's been 30 years, I want to watch another volcano do its thing!

[Kyle Holgate]

Found this just now - makes sense.

http://www.sciencedaily.com/releases/2009/01/090110084653.htm


I have often heard the analogy comparing a soda bottle to a volcano. Gas under pressure remains dissolved in the liquid. When the pressure is lowered (opening the bottle) the gas expands out of solution and fizzes out.
We all know that if you shake up a soda before opening things get even more interesting. So shaking up a volcano may do something similar - and also "jiggle" the conduits maybe to weaken areas where magma and volcanic gasses can get through.

I know it's a lot more complicated than that, but it may not have to be anything harder than shaken Coke!

[old_pop2000]

Found this just now - makes sense.

http://www.sciencedaily.com/releases/2009/01/090110084653.htm


I have often heard the analogy comparing a soda bottle to a volcano. Gas under pressure remains dissolved in the liquid. When the pressure is lowered (opening the bottle) the gas expands out of solution and fizzes out.
We all know that if you shake up a soda before opening things get even more interesting. So shaking up a volcano may do something similar - and also "jiggle" the conduits maybe to weaken areas where magma and volcanic gasses can get through.

I know it's a lot more complicated than that, but it may not have to be anything harder than shaken Coke!

T'anks, Mate. I've read some reports alluding to this. That's why I asked about the scenario for the NW. It's similar to the possible super eruption of Yellowstone. a large earthquake shakes the soda bottle(the magma chamber) and disrupts the plumbing on the whole system and whammo, its dust and ash over 2/3 of the eastern US.

[Kyle Holgate]

The fact that most of the larger volcanoes were active at about the same time as the last Cascadia quake is quite interesting. I'd like to see someone attempt to correlate previous quakes on the zone to previous volcanic activity. You can often get good radio carbon dates from stuff buried in basalt lava or crispied in a pyroclastic flow, the trick is finding the material in the debris. Finding the subduction zone materials for dating is way easier - it's not toasted and buried under rock, it's just drowned and buried under muck.

[Kyle Holgate]

Here's what you can do with using P and S waves... Interesting to get a clue what the plumbing of ol' St. Helens is like.

http://www.unc.edu/~leesj/FETCH/Papers/LEES_92_MSH_TOMO.pdf

[Ed Rotondaro]

Here's what you can do with using P and S waves... Interesting to get a clue what the plumbing of ol' St. Helens is like.

http://www.unc.edu/~leesj/FETCH/Papers/LEES_92_MSH_TOMO.pdf

Kyle:

Way too much math there!:eek:

[Mike D]

T'anks, Mate. I've read some reports alluding to this. That's why I asked about the scenario for the NW. It's similar to the possible super eruption of Yellowstone. a large earthquake shakes the soda bottle(the magma chamber) and disrupts the plumbing on the whole system and whammo, its dust and ash over 2/3 of the eastern US.

The soda bottle analogy is good but we like to consider more of a champagne analogy, champagne bottle has a longer tapering neck, there is more CO2 in champagne and champagne is classier then Big Red. Uncork the bottle and the CO2 expands and greats a 'froth' lower in density but greater in volume. As the the champagne expands up the neck the neck contracts and now you have contraction of an expanding fluid(Bernoulli principle basically) and as the froth rises up the neck there is less pressure on the fluid which allows the bubbles to expand further and on it goes. Essentially you have your initial out gassing in the magma chamber and then from there the expansion of the gas bubbles increases at a exponential rate as it goes up the volcano neck. So a small simple out gassing can end up being like jet exhaust. Its actually rare for more then 20% of a magma chamber to be ejected in an eruption. Estimates on Mt. St. Hellens run to the 12% range. Think what it would have been if 50% of the chamber would have been ejected!!!

Yellowstone and caldera type volcanos are kind of like the ugly step child to vulcanologists. It seem like if it doesn't make a cone it can't be a volcano to some. Anyway caldera types erupt differently then all the others. Here the magma chamber is close to the surface, more oval in shape instead of round, is under lower pressure and is more basaltic where continental volcanos tend towards the andesitic(if that make no sense I can explain). Caldera type tend towards magma flows instead of explosions. So the theory on Yellowstone is that at some time magma will find its way to the surface via existing or new fractures and faults and create lava fountains which will cause large lava pools and/or flows. It might stop here if the chamber pressure isn't too high and the magma cools and plugs the fracture. Or if the pressure in the chamber is high and/or there are many lava flows and fountains via lots of faults then the magma chamber can empty considerably. This is where the real nastiness happens. As the shallow magma chamber empties the roof of the chamber is no longer supported by the magma and eventually collapses. I don't know if you've ever seen a souffle collapse bu its the same thing. First the roof over the center of the chamber collapses falling down onto the magma which squirts out more magma under pressure emptying more magma which makes more of the roof collapse which pushes out more magma which creates more space which causes more rood to collapse and now you in a positive feed back cycle. Caldera type volcanos that collapse will eject about 85% of the magma in the chamber. If you imagine it this is the type of volcano that could go in for days under pressure but when the chamber collapse starts its almost a sustained explosion. Then there would be a sudden end as the collapse ends. This is why they are called "super volcanos". What your left with is a hole in the ground, as in the case of Yellowstone's 3 major eruptions, running from a smallish 10 miles in diameter to the largest that is 60 milesx40 miles. So do the math, if a magma chamber 10 miles in diameter explodes (I'll use a sphere to make the math simple) ejecting 80% of the magma chamber then that would be about 419 cubic miles of lava. So roughly thats enough lava to cover an area 1485 miles x 1485 miles 1 foot deep in lava. And thats the small eruption. (Note: take all my numbers with a grain of salt, they are educated WAGs but still WAGs.)

[Kyle Holgate]

And the magma from the caldera types often comes out as pumice or similar rock - so it's inflated (so to speak) with gas bubbles. At Crater lake it's fun to toss rocks in and watch them float away (!).
When you have magma with the consistency roughly of play dough and it's gas charged, it tends to shred itself when the pressure is lowered. So unlike the champagne bottle idea, the gas can't get out through the viscous magma and blows it apart. Some of it does stay together and puffs into pumice.

At Crater lake it's interesting (for a volcano geek like me at least) in that you can see the progression of the caldera eruption. You have lots of air fall ash, then pumice and pyroclastic flow deposits and some welded tuff. This is where the stuff coming out is still hot enough when it lands to weld itself back together. Finally you start to see darker and darker material on top of this stuff as the magma from lower in the chamber is "spit up". This darker stuff was less viscous so won't float. The theory (one of them anyway) is that the magma chamber had light rhyolite magma setting on top of andesite - all nicely charged up with gas.
Mazama (the mountain that turned into crater lake) was 'only' a vei 7 eruption - roughly 100 times St. Helens. The Yellowstone eruptions have been up to VEI 8 - 1,000 times St. Helens' 1980 blast.

VEI = volcano explosivity index http://en.wikipedia.org/wiki/Volcanic_Explosivity_Index

[djcyclone]

After reading the latest post about Yellow Stone, is it an accurate assumption to say that the United States may not survive an eruption of that magnitude?

I mean would that be the straw, (or Anvil) that breaks the Camels Back? I do hope that our Allies would come to our aid in that situation, but one never knows.

[old_pop2000]

After reading the latest post about Yellow Stone, is it an accurate assumption to say that the United States may not survive an eruption of that magnitude?

I mean would that be the straw, (or Anvil) that breaks the Camels Back? I do hope that our Allies would come to our aid in that situation, but one never knows.

Much of it depends on the type of eruption. If it is a supereruption then 2/3 of the US will have some extreme difficulty. The midwest is toast as it will dump a very thick coat of ash on that area. But, we only have the past as a guide and our estimates of the cubic displacement of the magma chamber.

Mike D and Kyle may be able to shed more light on this subject.

[djcyclone]

I wonder if one day someone will find a way to safely release preasure from a Volcano before it erupts.

I mean we already know how to find them, so what if there was a way to safely release the preasure and then calm the Volcano down.

[old_pop2000]

I wonder if one day someone will find a way to safely release preasure from a Volcano before it erupts.

I mean we already know how to find them, so what if there was a way to safely release the preasure and then calm the Volcano down.

We need to crawl, before we can walk. Let's just hope we can get a full understanding of the processes at work, so we can get an effective advanced warning system. Controlling mother earth comes much, much later.;)

[old_pop2000]

For all of you in the Pacific Northwest.

http://cosmiclog.msnbc.msn.com/archive/2009/04/09/1886433.aspx

[djcyclone]

We need to crawl, before we can walk. Let's just hope we can get a full understanding of the processes at work, so we can get an effective advanced warning system. Controlling mother earth comes much, much later.;)



Well I mean you would think it wouldn't be that hard. I mean we already know that Old Faithfull is faithfull because it is releasing preasure, so if there was a way to drill deep enough into the earth and open the volcano so that some of the preasure could be released, but not all.

That is withouth triggering a (CHAIN REACTION).:eek:

[old_pop2000]

Well I mean you would think it wouldn't be that hard. I mean we already know that Old Faithfull is faithfull because it is releasing preasure, so if there was a way to drill deep enough into the earth and open the volcano so that some of the preasure could be released, but not all.

That is withouth triggering a (CHAIN REACTION).:eek:


Actually, the material in the magma chamber has the consistency of a sponge. As soon as you drilled, it would seal right back up as the magma rose through the hole. Sorry, drilling won't work.:p

[djcyclone]

Actually, the material in the magma chamber has the consistency of a sponge. As soon as you drilled, it would seal right back up as the magma rose through the hole. Sorry, drilling won't work.:p

The Magma would be hot enough to stay in liquid form until it reached the surface. Then it would cool down and become a solid rock.

If you drilled enough holes, then you would be able to do that, but then where to you put the dirt that you are digging up, and what do you do with all the new mounds that appear over each hole?

Also who do you get that is dumb enough to do this, but also smart enough to man the equipment that can drill the hole?:p

[Kyle Holgate]

The magma chamber under Yellowstone is HUGE. We simply don't have the technology to do anything with it yet, and probably won't for hundreds of years, even if we understood exactly what to do (which we don't).
Here is a graphic of the magma chamber at Yellowstone http://www.eurekalert.org/multimedia/pub/web/5718_web.jpg

Right now - if we had the money we might just wake it up by putzing around with it - if we could even effect it at all.

If it goes off like it did with the last super eruption - 600,000 years ago or so the impact on the US would be immense. The entire heartland would be covered in ash and crops would fail, even if the people and livestock managed to get through it. Then the global impact would hit - we really don't know what it would do to the weather, but smaller eruptions such as Tambora last century caused what is called the year without a summer in New England. Frost in July, crops failing, etc.
Yellowstone is like the NW subduction zone quake. It's almost certainly going to happen, but I hope I'm long gone when it does.

[Ed Rotondaro]

The magma chamber under Yellowstone is HUGE. We simply don't have the technology to do anything with it yet, and probably won't for hundreds of years, even if we understood exactly what to do (which we don't).
Here is a graphic of the magma chamber at Yellowstone http://www.eurekalert.org/multimedia/pub/web/5718_web.jpg

Right now - if we had the money we might just wake it up by putzing around with it - if we could even effect it at all.

If it goes off like it did with the last super eruption - 600,000 years ago or so the impact on the US would be immense. The entire heartland would be covered in ash and crops would fail, even if the people and livestock managed to get through it. Then the global impact would hit - we really don't know what it would do to the weather, but smaller eruptions such as Tambora last century caused what is called the year without a summer in New England. Frost in July, crops failing, etc.
Yellowstone is like the NW subduction zone quake. It's almost certainly going to happen, but I hope I'm long gone when it does.

Hey Volcano Heads:

On this day in 1815, Mt. Tamboura erupted killing 71,000 people in one of the worst volcanic disasters in history (thank god for Wikipedia).

[Kyle Holgate]

Hey Volcano Heads:

On this day in 1815, Mt. Tamboura erupted killing 71,000 people in one of the worst volcanic disasters in history (thank god for Wikipedia).

I should know that - I screwed up in my last post on Yellowstone and said Tambora was last century instead of centruy before last! Pele and Tahoma are not going to be happy with me!
You want to see a BIG caldera, go find Toba on google earth. That is thought to be the most recent super eruption.
Or just look at this...
http://images.google.com/imgres?imgurl=http://tobavolcano.googlepages.com/toba1.jpg/toba1-full%3Bcrop:0.09,0.03,0.95,0.9.jpg&imgrefurl=http://tobavolcano.googlepages.com/&usg=__00HLKvyIe3v39VJxg3SbBQ1lCYk=&h=1076&w=683&sz=60&hl=en&start=9&um=1&tbnid=IOQLPodBt7YaLM:&tbnh=150&tbnw=95&prev=/images%3Fq%3DToba%2Beruption%26hl%3Den%26rls%3Dcom .microsoft:en-us:IE-SearchBox%26rlz%3D1I7TSHB_en%26sa%3DN%26um%3D1

This one is thought to have almost driven us Humans extinct. Not sure that would be a bad thing from a planetary standpoint, but...

[Ed Rotondaro]

I should know that - I screwed up in my last post on Yellowstone and said Tambora was last century instead of centruy before last! Pele and Tahoma are not going to be happy with me!
You want to see a BIG caldera, go find Toba on google earth. That is thought to be the most recent super eruption.
Or just look at this...
http://images.google.com/imgres?imgurl=http://tobavolcano.googlepages.com/toba1.jpg/toba1-full%3Bcrop:0.09,0.03,0.95,0.9.jpg&imgrefurl=http://tobavolcano.googlepages.com/&usg=__00HLKvyIe3v39VJxg3SbBQ1lCYk=&h=1076&w=683&sz=60&hl=en&start=9&um=1&tbnid=IOQLPodBt7YaLM:&tbnh=150&tbnw=95&prev=/images%3Fq%3DToba%2Beruption%26hl%3Den%26rls%3Dcom .microsoft:en-us:IE-SearchBox%26rlz%3D1I7TSHB_en%26sa%3DN%26um%3D1

This one is thought to have almost driven us Humans extinct. Not sure that would be a bad thing from a planetary standpoint, but...

Kyle:

That would have caused a massive climatic change. That is definitely an extinction event. We don't rule the world, we just live here at Mother Nature's whim.

[old_pop2000]

Kyle:

That would have caused a massive climatic change. That is definitely an extinction event. We don't rule the world, we just live here at Mother Nature's whim.


Call me the eternal optimist, but man did not become extinct 70000 years ago when Tambora blew its lid. We got close, but I believe strongly that we are a resilient species and very adaptive. Despite our dependence on technology, watching how people in the world or in the US handle natural disasters seems to give me hope. I will survive!! (as the Gloria Gaynor song relates)

[Kyle Holgate]

Call me the eternal optimist, but man did not become extinct 70000 years ago when Tambora blew its lid. We got close, but I believe strongly that we are a resilient species and very adaptive. Despite our dependence on technology, watching how people in the world or in the US handle natural disasters seems to give me hope. I will survive!! (as the Gloria Gaynor song relates)

We act like the supposedly non-intelligent animals though. We are populating like bunnies, eating ourselves out of our food supply, fouling our water more and more and going on like we aren't smart enough to know that we cannot sustain this. Who's going to come along and clean the cage and put in fresh food and water for us?

I agree that a super volcano, new ice age, etc probably would not cause human extinction now. It would mean the death of millions or billions perhaps. I was thinking about it the other day - that our local area (Portland metro area) could not sustain its own population without the trucks and trains and what not bringing in food constantly. Maybe with some warning and everyone putting in veggies instead of lawns we could though.
What strikes me about Yellowstone is that the impact on the country would be right in the bread-basket of the US. With evacuations there may not be many deaths directly attributed to the eruption (from pyroclastic flows, lahars and what not) but the cost in food production capacity would be a disaster near term. Longer term the cooling might put California out of much of its food production for a while. We can live of turnips and Cabbage - they grow in colder climates! If the US stopped shipping grain overseas though, what happens? Just how much of the world DO we feed?

I hope I am fertilizer when Yallowstone goes pop.

[old_pop2000]

We act like the supposedly non-intelligent animals though. We are populating like bunnies, eating ourselves out of our food supply, fouling our water more and more and going on like we aren't smart enough to know that we cannot sustain this. Who's going to come along and clean the cage and put in fresh food and water for us?

I agree that a super volcano, new ice age, etc probably would not cause human extinction now. It would mean the death of millions or billions perhaps. I was thinking about it the other day - that our local area (Portland metro area) could not sustain its own population without the trucks and trains and what not bringing in food constantly. Maybe with some warning and everyone putting in veggies instead of lawns we could though.
What strikes me about Yellowstone is that the impact on the country would be right in the bread-basket of the US. With evacuations there may not be many deaths directly attributed to the eruption (from pyroclastic flows, lahars and what not) but the cost in food production capacity would be a disaster near term. Longer term the cooling might put California out of much of its food production for a while. We can live of turnips and Cabbage - they grow in colder climates! If the US stopped shipping grain overseas though, what happens? Just how much of the world DO we feed?

I hope I am fertilizer when Yallowstone goes pop.

I have a map of the Huckleberry Ridge Ash Bed, Mesa Falls, and Lava Creek. You observation about your region not affected by any of those. However, if the Cascadia Seismic Zone unzips, you might want to be in another section of the US.

Southern California has more to fear from the Long Valley Caldera and its ash cloud, than it does the Yellowstone area.

http://www.solcomhouse.com/yellowstone.htm

[djcyclone]

Would Central Illinois be close enough to get any ash from Yellow Stone?

I plan on moving to Australia anyway. I will take my chances in the dessert.

[old_pop2000]

Would Central Illinois be close enough to get any ash from Yellow Stone?

I plan on moving to Australia anyway. I will take my chances in the dessert.

Well, those three ash deposits don't touch Illinois, although it's close. However, it's hard to visualize the ash cloud from a super eruption of the current location of the Yellowstone caldera. Remember that the hot spot that created the three previous, is moving NE, IIRC. Maybe Mike or Kyle remember. I would have to look it up.

Note: there is another ash bed, termed the Bishop Ash Bed created as a result of Long Valley eruption in California. There is a Long Valley Observatory and the current status is normal, green. The eruption occurred about 760,000 years ago. If you visit Mammoth Mountain in California for skiing. You are on the rim of the Long Valley caldera. Other areas are the Inyo-Mono Craters volcanic chain.

As you can see, we, in Southern California have our own supervolcano to contend with. The next eruptions are likely to be similiar to the last Mono-Inyo event about 5000 years ago.

[Kyle Holgate]

Would Central Illinois be close enough to get any ash from Yellow Stone?

I plan on moving to Australia anyway. I will take my chances in the dessert.

The link Dennis provided doesn't say what the shaded areas mean (that I saw anyway). They could be ashfall at some measurable amount - say 5 cm or .5 meters or something. I would not be a bit surprised if a super eruption at Yellowstone dusted areas all the way to the east coast. From my experience with St. Helens and as you'd expect - further means less and less ash until there is none, of course dependant on winds. Prevailing winds are from west to east across the US so Chicago, Memphis, much of Texas, etc. would see some ash I'd bet.
It doesn't take much to mess with you. Our first St.Helens dusting wasn't measurable, but was annoying. It made clouds behind cars, messed with grazing for cattle (they didn't like the grit) and generally caused problems with equipment as ash is a great grinding agent. 2nd shot we got where I lived was about 3/4 inch - that was amazingly bothersome. It got everywhere and made huge clouds behind cars until it eventually settled on road shoulders. Some people would "smoke screen" the police by driving over just a bit toward the shoulders where the ash had piled. Not me of course :D.
Ash is hell on combines and harvesting equipment, makes cows give less milk and eat less, kills lots of insects (like bees). Birds have problems, and insect eating birds obviously have more. Even a dusting of ash over the mid section of the nation would be a major disaster.

Long valley doesn't get much news, but it has shown more activity than Yellowstone in the last 50 years or so. I remember back in the early 80's when they thought it was going to have an eruption.
One thing to keep in mind about the super volcanoes. They have much smaller eruptions too, not every pop is a BIG pop. Long valley is an interesting place to snoop - I took a vacation and went down there some years back. Quite a fun place for a volcano geek.

[old_pop2000]

The link Dennis provided doesn't say what the shaded areas mean (that I saw anyway). They could be ashfall at some measurable amount - say 5 cm or .5 meters or something. I would not be a bit surprised if a super eruption at Yellowstone dusted areas all the way to the east coast. From my experience with St. Helens and as you'd expect - further means less and less ash until there is none, of course dependant on winds. Prevailing winds are from west to east across the US so Chicago, Memphis, much of Texas, etc. would see some ash I'd bet.
It doesn't take much to mess with you. Our first St.Helens dusting wasn't measurable, but was annoying. It made clouds behind cars, messed with grazing for cattle (they didn't like the grit) and generally caused problems with equipment as ash is a great grinding agent. 2nd shot we got where I lived was about 3/4 inch - that was amazingly bothersome. It got everywhere and made huge clouds behind cars until it eventually settled on road shoulders. Some people would "smoke screen" the police by driving over just a bit toward the shoulders where the ash had piled. Not me of course :D.
Ash is hell on combines and harvesting equipment, makes cows give less milk and eat less, kills lots of insects (like bees). Birds have problems, and insect eating birds obviously have more. Even a dusting of ash over the mid section of the nation would be a major disaster.

Long valley doesn't get much news, but it has shown more activity than Yellowstone in the last 50 years or so. I remember back in the early 80's when they thought it was going to have an eruption.
One thing to keep in mind about the super volcanoes. They have much smaller eruptions too, not every pop is a BIG pop. Long valley is an interesting place to snoop - I took a vacation and went down there some years back. Quite a fun place for a volcano geek.

I am still looking for some data on the depth of the ash fall. I have seen information that the Yellowstone Huckleberry Ridge Tuff has been discovered in deep sea cores from the Northeastern Pacific Ocean. As the information stated, winds move from west to east, this tuff had to have traveled around the earth and precipitated out at this point. It also stated that sea water preserves ash better. That seems to indicate that the ash clouds do circumnavigate the globe and can be found almost everywhere. That's comforting. It was dated about 2.5 M.a.

[old_pop2000]

According to one report, there is one sheet of Huckleberry Ridge Tuff that is 130 meters in thickness. This is in a 20 km by 20 km area between the south flank of the Big Bend Ridge and the Teton River. That is probably the edge of the 2.0 Ma caldera. That's a lot of ash fall, even close to the eruption zone.

[Kyle Holgate]

I am still looking for some data on the depth of the ash fall. I have seen information that the Yellowstone Huckleberry Ridge Tuff has been discovered in deep sea cores from the Northeastern Pacific Ocean. As the information stated, winds move from west to east, this tuff had to have traveled around the earth and precipitated out at this point. It also stated that sea water preserves ash better. That seems to indicate that the ash clouds do circumnavigate the globe and can be found almost everywhere. That's comforting. It was dated about 2.5 M.a.

Ash in the Pacific could have come down rivers such as the Columbia and Fraser in British Columbia. Just guessing there but I would not expect noticeable ash fall to circumnavigate the globe. A bit of dust a thousand miles down wind maybe, but not all the way 'round!

[old_pop2000]

Ash in the Pacific could have come down rivers such as the Columbia and Fraser in British Columbia. Just guessing there but I would not expect noticeable ash fall to circumnavigate the globe. A bit of dust a thousand miles down wind maybe, but not all the way 'round!

We have evidence that fine ash that reaches the stratosphere(25000 feet) may circle the globe many times before it settles. Particle size does decrease downwind from the eruptions. Thickness also decreases.

In 1986, the ash cloud from the Lascar Volcano was tracked by GOES images. The area covered was about 112,000 square kilometers. We know that ash from the volcano was tracked and detected in the upper troposphere at speeds up to 180 km per hour or 110 MPH. The ash cloud reached up to 15 km in altitude. That's about 49,000 feet, well within the stratosphere.

[john964]

We act like the supposedly non-intelligent animals though. We are populating like bunnies, eating ourselves out of our food supply, fouling our water more and more and going on like we aren't smart enough to know that we cannot sustain this. Who's going to come along and clean the cage and put in fresh food and water for us?

I agree that a super volcano, new ice age, etc probably would not cause human extinction now. It would mean the death of millions or billions perhaps. I was thinking about it the other day - that our local area (Portland metro area) could not sustain its own population without the trucks and trains and what not bringing in food constantly. Maybe with some warning and everyone putting in veggies instead of lawns we could though.
What strikes me about Yellowstone is that the impact on the country would be right in the bread-basket of the US. With evacuations there may not be many deaths directly attributed to the eruption (from pyroclastic flows, lahars and what not) but the cost in food production capacity would be a disaster near term. Longer term the cooling might put California out of much of its food production for a while. We can live of turnips and Cabbage - they grow in colder climates! If the US stopped shipping grain overseas though, what happens? Just how much of the world DO we feed?

I hope I am fertilizer when Yallowstone goes pop.
Kyle, The US feed quite a lot of the world of the 5 major grains Wheat Rice Oats Corn and Barley.

IIRC this is the breakdown
Wheat 60-65% with Canada Austrilia Argentina and Ukrane making up the rest
Rice 75% with China Japan and SE Asia the rest.
Oats 60%
Corn 55%
Barley 60%

Things like fruit is up there also. Depending on the fruit US production is 40-70% of world supply.

[Kyle Holgate]

We have evidence that fine ash that reaches the stratosphere(25000 feet) may circle the globe many times before it settles. Particle size does decrease downwind from the eruptions. Thickness also decreases.

In 1986, the ash cloud from the Lascar Volcano was tracked by GOES images. The area covered was about 112,000 square kilometers. We know that ash from the volcano was tracked and detected in the upper troposphere at speeds up to 180 km per hour or 110 MPH. The ash cloud reached up to 15 km in altitude. That's about 49,000 feet, well within the stratosphere.

Ash can get 90,000 feet up - and yes, of course it settles out eventually. That it's something that can be detected and measured over 3/4 of the way around the planet though is where I am skeptical, even for a super-eruption. Tambora was the largest eruption in historic times, they didn't get a dusting in India, Africa or Brazil, or not enough for anyone to notice at least. That's all I'm saying - the ash/gas cloud can go all around if it gets high enough (St. Helens did, more than once).
If ash was found in the Pacific, then I'm betting it got there through some other means than wind blown depositation or their meains of finding it was using microscopes and detecting very minute quantities.

[old_pop2000]

Ash can get 90,000 feet up - and yes, of course it settles out eventually. That it's something that can be detected and measured over 3/4 of the way around the planet though is where I am skeptical, even for a super-eruption. Tambora was the largest eruption in historic times, they didn't get a dusting in India, Africa or Brazil, or not enough for anyone to notice at least. That's all I'm saying - the ash/gas cloud can go all around if it gets high enough (St. Helens did, more than once).
If ash was found in the Pacific, then I'm betting it got there through some other means than wind blown depositation or their meains of finding it was using microscopes and detecting very minute quantities.

Satellite collection and observations, aircraft collections etc. all seem to indicate and support the theory that ash clouds have and do, reach altitudes high enough to circumnavigate the globe. Now, will some of it settle and enter the Atlantic conveyor and be deposited by it, in other spots on the globe. I am certain that a portion of the total ash ejected does settle into the great currents in the oceans and eventually be redistributed. However, that material would be diffused to a great degree and would only be observed in small amounts per quantity of sea floor sediments. Large, thick deposits in the undersea stata would indicate a large concentration that did not get seaborne to the position.

[john964]

Satellite collection and observations, aircraft collections etc. all seem to indicate and support the theory that ash clouds have and do, reach altitudes high enough to circumnavigate the globe. Now, will some of it settle and enter the Atlantic conveyor and be deposited by it, in other spots on the globe. I am certain that a portion of the total ash ejected does settle into the great currents in the oceans and eventually be redistributed. However, that material would be diffused to a great degree and would only be observed in small amounts per quantity of sea floor sediments. Large, thick deposits in the undersea stata would indicate a large concentration that did not get seaborne to the position.
I remember reading about "pumace rafts" after Kraktau eruption in 1889 that were washing up on Africa as late a 1895. These rafts were several feet thick and some that were spotted at sea covered several square miles.

[old_pop2000]

I remember reading about "pumace rafts" after Kraktau eruption in 1889 that were washing up on Africa as late a 1895. These rafts were several feet thick and some that were spotted at sea covered several square miles.


Pumice rafts are not a well understood phenomenon. Records show that a large pumice raft washed up on the shore of Zanzibar 3000 miles away from Krakatoa. Rafts of Krakatoa pumice were washing up on the shores of Melanesia two years later. Apparently they were reported in 1979 and 1984 after eruptions around Tonga. On 28 August 1986, floating pumice blocked the water inlet filter of a dutch motor vessel. The nearest eruption was an underwater volcano, 180 miles away. Still, scientist are not entirely certain how they form and stay together. It is estimated that ecosystems might be regenerated by flora and fauna attaching themselves to these rafts and moving to other areas. Many undersea volcanos and such, are being studied by using these rafts.

[Kyle Holgate]

The other way ash could get into the Pacific is that the winds, though usually from the west are not always. Mt. Mazama ash from the caldera collapse eruption 7000 years ago covered areas to the north and west, though most went northeast and east. That plus rivers strike me as though they'd be able to deposit more ash in the ocean than fine airborne or ocean currents would. A combination of all maybe would be enough to notice? They can detect big eruptions in ice cores too though I forget right now exactly how they do it - I think it's sulfur particles (it's bed time, not gonna look it up right now - YAWN -).

Pumice is interesting stuff. It is so counter-intuitive to toss a rock into the water and have it float. Since it's basically glass foam, water does not soak into it very fast. A dry piece would float a long time, and it comes out of a volcano quite dry and of course quite hot.

[old_pop2000]

Another volcano eruption, this time in the Galapagos. La Cumbre.

http://news.yahoo.com/s/ap/lt_ecuador_galapagos_volcano

[Mike D]

Ok, that's great. So turbidites are the opposite of what we usually see. In the turbidites, we see a sorting of smaller particles like a sieve, where the finer stuff stays on top. In river deposits, like you indicated, it works the opposite. So, can geologist use the presence of these turbidites to develop a timeline of seismic activity by measuring the thickness of the layers and the types of materials?

BTW, thanks for the vids. Man, am I going to have fun with all this.

Ok Dennis I have a kind of answer for your question. Essentially no, but there are about 10 caveats and qualifiers to the answer. Generally no because there isn't a 1-to-1 relationship to quakes and turbidites. You may or may not get a turbidite flow with a coastal quake and quake size doesn't correlate to turbidite flow size. Think mountains and snow; a big quake on a small mountain with just a foot of snow will give you a small avalanche, but a tiny quake on a huge mountain with 24ft of snow could give you a monster avalanche.

That said there is info that could correlate. If you could definitively correlate the quake and the flow then if enough is known about the pre-flow turbidite deposits, the flow and quake are in the same provenance, etc. then you may be able to evaluate some factors of one based on the other. The problem is not a lot of research has been done in the area. I did run across a paper "Scaling in Turbidite Deposits" by Rothman/Grotzinger/Flemmings where they tried to equate flow size and bedding size to seismic events but they had little luck. I asked 3 eggheads in the geology departments about it and each said instantly no, but then when I pushed them they all got that glassy eyed far-away look and changed their answer to 'no but...'. The question even got one professor curious enough he is going to get a grad student to do some research on it to see if its worth a full blown research project.

Good thinking Dennis.