Comments on: Quake! http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/ Random samplings from a universe of ideas. Mon, 23 Nov 2009 07:25:28 -0600 http://wordpress.org/?v=2.8.4 hourly 1 By: Lab Lemming http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45717 Lab Lemming Fri, 01 Aug 2008 01:12:01 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45717 The parkfield quake finally happened in 2004... The parkfield quake finally happened in 2004…

]]> By: Xenophage http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45716 Xenophage Thu, 31 Jul 2008 17:19:24 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45716 Good news: Caltech's tall thin Milliken Library was built fully instrumented from the inside outward. That temblor awarded somebody a thesis. Bad news: The heroic (and heroically expensive) Parkfield installation is still waiting for something to happen locally. The model, the model... needs another parameter. Good news: Caltech’s tall thin Milliken Library was built fully instrumented from the inside outward. That temblor awarded somebody a thesis.

Bad news: The heroic (and heroically expensive) Parkfield installation is still waiting for something to happen locally. The model, the model… needs another parameter.

]]> By: Scott S http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45704 Scott S Thu, 31 Jul 2008 15:39:48 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45704 Just to close the loop on the Northridge question, I did use USGS' Ask-A-Geologist and got a quick and informative answer back. (see below) excuse me for the very bad pun, but the "USGS rocks!" I love being able to ask an expert. <blockquote> Thanks for contacting Ask-A-Geologist. I looked at the shakemaps for the event. I believe it is a combination of a couple of things. First, I believe it is real in that the intensity in Northridge was probably a little higher than the surrounding area because of amplification caused by soft soils in the basin in and around Northridge. This is a very common phenomena. The instrumentation may also be better there than in the intervening mountainous area between Northridge and the epicentral area, but the lower values would also be expected on bedrock as opposed to soft soils. Also, part of the information for shakemap is often generated by individuals reporting their experiences on the "Did you feel it" reporting website. However, I suspect that this map is more instrumentation driven than from subjective descriptions. </blockquote> Just to close the loop on the Northridge question, I did use USGS’ Ask-A-Geologist and got a quick and informative answer back. (see below)

excuse me for the very bad pun, but the “USGS rocks!” I love being able to ask an expert.

Thanks for contacting Ask-A-Geologist.

I looked at the shakemaps for the event. I believe it is a combination of a couple of things. First, I believe it is real in that the intensity in Northridge was probably a little higher than the surrounding area because of amplification caused by soft soils in the basin in and around Northridge. This is a very common phenomena. The instrumentation may also be better there than in the intervening mountainous area between Northridge and the epicentral area, but the lower values would also be expected on bedrock as opposed to soft soils. Also, part of the information for shakemap is often generated by individuals reporting their experiences on the “Did you feel it” reporting website. However, I suspect that this map is more instrumentation driven than from subjective descriptions.

]]> By: Lawrence B. Crowell http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45715 Lawrence B. Crowell Thu, 31 Jul 2008 03:22:26 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45715 Scott: Life seems to be filled with these things. No matter what you do the world is dynamic and it has a way of throwing banana peels in our paths. The one Earth system which I have intimate contact with are tornados. I have seen several of them, and I have been in two, one where I was in a car that got lifted up by the thing. They might seek me out --- or at least it seems that way. Maybe I shouldn't move to the gulf coast, the bigger cousin of the tornado called the hurricane might cme after me. Yet in a way these things do serve a good purpose for us. They tell us how really small and ultimately impotent we are. The only real power we have is a sort of virtual power, which is that of our mind. Lawrence B. Crowell Scott: Life seems to be filled with these things. No matter what you do the world is dynamic and it has a way of throwing banana peels in our paths. The one Earth system which I have intimate contact with are tornados. I have seen several of them, and I have been in two, one where I was in a car that got lifted up by the thing. They might seek me out — or at least it seems that way. Maybe I shouldn’t move to the gulf coast, the bigger cousin of the tornado called the hurricane might cme after me. Yet in a way these things do serve a good purpose for us. They tell us how really small and ultimately impotent we are. The only real power we have is a sort of virtual power, which is that of our mind.

Lawrence B. Crowell

]]> By: Scott S http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45714 Scott S Thu, 31 Jul 2008 02:47:37 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45714 Lab Lemming, Thanks for the explanation, I suspected something like that, but it has been many years since took geology. As far as waiting for a M > 8, I love science and all, but I think skip the quake experiment. Living near New Madrid, Missouri, we have enough concerns with our own "big one". In addition, I don't want CA to have a large quake, since the rest of country seems to follow CA lead. BTW, love the cat's blog, better writing then most. Lab Lemming,
Thanks for the explanation, I suspected something like that, but it has been many years since took geology. As far as waiting for a M > 8, I love science and all, but I think skip the quake experiment. Living near New Madrid, Missouri, we have enough concerns with our own “big one”. In addition, I don’t want CA to have a large quake, since the rest of country seems to follow CA lead.

BTW, love the cat’s blog, better writing then most.

]]> By: Lab Lemming http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45713 Lab Lemming Thu, 31 Jul 2008 01:35:18 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45713 ScottS: The color map shown by Sean denotes ground shaking, which is a function of earthquake energy and local geologic conditions such as soil type. Areas with poorly compacted soil generally shake more. So if you can find a soil map of the LA basin, that might provide a clue as to why the shaking was greater is certain areas. And if y'all like graphs and waveforms, just wait for the big one- earthquakes with M > 8 can excite the free oscillation modes of the Earth. ScottS:
The color map shown by Sean denotes ground shaking, which is a function of earthquake energy and local geologic conditions such as soil type. Areas with poorly compacted soil generally shake more. So if you can find a soil map of the LA basin, that might provide a clue as to why the shaking was greater is certain areas.

And if y’all like graphs and waveforms, just wait for the big one- earthquakes with M > 8 can excite the free oscillation modes of the Earth.

]]> By: Lawrence B. Crowell http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45706 Lawrence B. Crowell Thu, 31 Jul 2008 00:45:31 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45706 It is funny about your cat. My cat and I had, the cat has since gone to the happy mouse hunting grounds, a sort of adversarial play relationship. Getting the cat to jump up with a start was always fun. Sounds like the quake did that for you. Lawrence B. Crowell It is funny about your cat. My cat and I had, the cat has since gone to the happy mouse hunting grounds, a sort of adversarial play relationship. Getting the cat to jump up with a start was always fun. Sounds like the quake did that for you.

Lawrence B. Crowell

]]> By: Pieter Kok http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45703 Pieter Kok Wed, 30 Jul 2008 22:07:17 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45703 Phil Plait had a <a href="http://blogs.discovermagazine.com/cosmicvariance/badastronomy/2008/07/30/shakin-up-astrological-nonsense/" rel="nofollow">nice post</a> about it, too. Phil Plait had a nice post about it, too.

]]> By: JCF http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45712 JCF Wed, 30 Jul 2008 21:52:06 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45712 Rocked the house and rattled the windows here in San Diego, just south of UCSD campus. SoCal has been lucky; the bad news has been the horrific epidemic of forest fires to the north, one now threatening Yosemite. Rocked the house and rattled the windows here in San Diego, just south of UCSD campus. SoCal has been lucky; the bad news has been the horrific epidemic of forest fires to the north, one now threatening Yosemite.

]]> By: Sean http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/comment-page-1/#comment-45711 Sean Wed, 30 Jul 2008 21:44:25 +0000 http://blogs.discovermagazine.com/cosmicvariance/2008/07/30/quake/#comment-45711 Message being sent around to Caltech people: TO: The Campus Community FROM: Dean Currie, Vice President for Business and Finance RE: Update on Yesterday's Earthquake In the spirit of a quick update on yesterday's earthquake: Caltech had no injuries. We had some chemical spills that required temporary evacuation in at least one building. We had minor damage, including broken water pipes in Noyes and in the Cogen plant. Four elevators went temporarily off line. The campus responded as you would have hoped. Everyone did their part - from the daycare center to the environmental health and safety group, facilities, computing and telecommunications, to individuals in all the buildings and labs, and to HR for the notice to be thoughtful of those employees whose homes were closer to the epicenter. I assume that it was by coincidence that, at the time of the earthquake, the Caltech Trustees were being given a tour of the Seismological Lab. I am told that they were impressed. Public Relations and the Seismo Lab must have been busy. I counted 10 media trucks parked outside as I left campus last night. Message being sent around to Caltech people:

TO: The Campus Community
FROM: Dean Currie, Vice President for Business and Finance

RE: Update on Yesterday’s Earthquake

In the spirit of a quick update on yesterday’s earthquake:

Caltech had no injuries. We had some chemical spills that required temporary evacuation in at least one building. We had minor damage, including broken water pipes in Noyes and in the Cogen plant. Four elevators went temporarily off line. The campus responded as you would have hoped. Everyone did their part – from the daycare center to the environmental health and safety group, facilities, computing and telecommunications, to individuals in all the buildings and labs, and to HR for the notice to be thoughtful of those employees whose homes were closer to the epicenter.

I assume that it was by coincidence that, at the time of the earthquake, the Caltech Trustees were being given a tour of the Seismological Lab. I am told that they were impressed. Public Relations and the Seismo Lab must have been busy. I counted 10 media trucks parked outside as I left campus last night.

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