Andrew Alden (alden) Sat 7 May 11 13:30
The Catholics have several saints designated for earthquakes, foremost among them Saint Emidius. After the 1857 earthquake in southern California, the local bishop got permission to observe the saint's feast day. Around that time, too, the mountains near the epicenter got their current names, the San Emigdio Mountains and the Temblor Range. But that's neither here nor there... There are ways to open and close a crack in the ground big enough to swallow a man. You could have a landslide or just a riverbank slump that would open a headscarp crevasse, then the uphill side could slump down upon it. In the tumult of a major quake, most people wouldn't be able to tell the real cause. Apparently after 1906, when a team of geologists was exploring the San Andreas fault, one of them was fooled by a farmer who stuck one of his dead cows into the fault trace, hind end up. We can never rule out the capriciousness of humans.
Mark McDonough (mcdee) Sat 7 May 11 13:36
Hah, that's great!
Sharon Lynne Fisher (slf) Sat 7 May 11 16:18
Back in the 1980s, I think it was, the San Francisco librarian got curious about how the official death toll of the earthquake seemed so small when it seemed to her that she'd run across a lot more people than that who were claimed to have died in the quake. So she started keeping track and discovered that was indeed true. She also discovered things like photos where buildings destroyed by the quake were drawn back in again, and then had big clouds of smoke painted over them -- because insurance paid for fire and not for earthquakes. The book published about it was Denial of Disaster.
Mark McDonough (mcdee) Sat 7 May 11 17:22
Right, that was my memory of the controversy too. Yes, some of the really big modern buildings did survive (in some cases only to be burned) but there was a lot more death and destruction from the quake than was admitted at the time.
Sharon Lynne Fisher (slf) Sat 7 May 11 17:51
>only to be burned Dynamited, in some cases.
Mark McDonough (mcdee) Sat 7 May 11 18:06
Right! I just thought of another area that had a huge earthquake in historic times that most people don't think of as a high hazard area: Jamaica. In 1692, as all pirate fans know, the pirate haven of Port Royal was almost completely destroyed by an earthquake. Is the Caribbean basin an earthquake hazard area, and if so, would this expose the east coast of the US to tsunami hazards?
Sharon Lynne Fisher (slf) Sat 7 May 11 18:19
I'd forgotten about that one.
Andrew Alden (alden) Sat 7 May 11 19:23
The US Geological Survey is constantly doing studies about the tsunami hazard of Puerto Rico. But the threat is much greater to the island itself than to the continental USA. An unknown tsunami threat to the east coast is landslide tsunamis. All of the North Atlantic is susceptible. A large slide offshore of Norway inundated Scotland about 8,000 years ago; you can google it as the Storegga slide.
Sharon Lynne Fisher (slf) Sun 8 May 11 07:47
Wow. I didn't know Great Britain used to be attached to Denmark. And, oh goody, one of the causes of the Storegga Slides is thought to be methane release.
Peter Meuleners (pjm) Mon 9 May 11 10:49
There is a good NatGeo show on that land area. It's one of the many sources for the Atlantis myth.
Mark McDonough (mcdee) Mon 9 May 11 16:57
It may be one of the reasons people were kinda slow to build large coastal cities in Europe. Oral tradition might well have preserved that tale.
Michael C. Berch (mcb) Mon 9 May 11 17:31
Hmmm, interesting hypothesis. I can think of a lot of counter-examples from early ages, though -- Athens, Constantinople, Jaffa, Venice, Marseilles, Barcelona, Alexandria (OK, that's Africa). Although, notably, a number of those have "old port" districts but the main city is on higher ground. And Rome and London were major ports, but inland. Hmmm.
Mark McDonough (mcdee) Mon 9 May 11 17:39
Yeah, but all those are on the Med, right? The tsunami would have been most intense along the coasts of Scandinavia & the British Isles (apologies to Irish ancestors, but you know what I mean). I doubt if it would have made it into the Med at all through the Straits of Gibraltar.
Andrew Alden (alden) Mon 9 May 11 17:49
We're getting near the end of our exclusive discussion period, although no one is going to shut us down and I'll keep replying as long as anyone keeps asking. But I wanted to speak up for the scientist's sense of wonder when it comes to earthquakes. It's a beautiful thing that Earth is physically active and creates these energetic surges all the time. If Earth weren't alive in this way, we would have no mountains, probably no land at all, very little life that we would recognize, no mineral wealth -- no Earth. And these seismic signals give us almost the only way to analyze the inside of the planet deeper than drills can go. Like a doctor tapping your chest to sense the condition of your lungs, seismologists can sift through the pops and creaks and cracks and follow how their waves behave at all depths in th planet. Their instruments get better, and the experiments they organize using hundreds of seismographs give us the same unprecedentedly clear pictures of the interior that massed telescopes give us of the heavens. Seismologists will always have mixed feelings about the big events, which crate so much misery yet yield strong and intriguing signals. Fortunately, one promising avenue of research uses ambient seismic signals -- background noise -- to do the kind of seismology that once took a good jolt. Over time, this should allow seismologists to have less ambivalent feelings about large earthquakes and have the same mix of dread and awe the rest of us feel. In the meantime, maybe the rest of us can seek some of the curiosity and wonder in the scientist's view of earthquakes.
paralyzed by a question like that (debunix) Mon 9 May 11 19:07
Is it likely that there would be any new science coming out pretty quickly after an event like this reveals the earth's innards anew, or it that the kind of thing that takes years and years and many quakes to realize?
Andrew Alden (alden) Mon 9 May 11 22:05
A magnitude 9 event is particularly good at exciting the extremely slow oscillations that affect the entire planet. This kind of data is prized by the handful of specialists who do refined modeling of deep Earth structure. Of course, they may still be digesting similar data from Sumatra. The immediate scientific results will center around the crust and shallow mantle of Japan: how an event of this size took form in that tectonic setting, and what the stress changes in the region may mean for other earthquake-producing zones in Japan. A new piece of historical data has been added to the catalog, and modelers will be trying new tricks and reassessing older data in light of it. Engineers will know more about the dynamics of earthquake shaking at the maximum magnitudes that can be realistically planned for. Everyone -- first responders, emergency planners, insurers, government agencies at all levels, media, construction firms and regulators, and the common people all have much to learn from the March 11 quake, and experts from around the world will be applying the same lessons to their own countries. Considering the appalling death tolls of historical quakes, the Tohoku quake was much less deadly than it could have been elsewhere. We can all benefit.
Teleological dyslexic (ceder) Tue 10 May 11 20:42
Sorry to come in so late, I do not know what year it was but I got awakened in Manhattan city like a giant was shaking my bed, the building etc. The radio was out for half an hour... pets were upset as were pictures on the walls. Hard-rock shaker! ;-} T
Teleological dyslexic (ceder) Tue 10 May 11 20:43
Thanks for being here!
Gail Williams (gail) Tue 10 May 11 21:52
Great stuff. I have a question, Alden. One of the things I loved from geology text books was the that there was an older scale that is used to compare surface intensity, the thing we actually perceive on the ground. I know that a quake has one Magnitude and perhaps many local intensities, but it is a wonderful way to describe what happens on the surface. I love the use of "Did You Feel It?" questionaires in making crowd-sourced shake maps. With GPS-enabled devices it could become even more precise in time, though now it is by zipcode. Here's one sample of what I'm looking at: < http://earthquake.usgs.gov/earthquakes/dyfi/events/ci/14978652/us/index.html> What do you think of shake mapping for participatory quake reporting and awareness? Is it of any use for science, too?
Andrew Alden (alden) Tue 10 May 11 22:17
ShakeMap is now considered as robust as traditional methods for making intensity maps, Gail. And of course every person who fills in the form in reporting their quake experience is aware of earthquakes in a way they weren't before. It's like the people who light their flames at rock concerts: a little thing for each person, but we create an impresive communal event. The other day I was thinking about the stadium experience called "the wave," where the people in one section of seats lift their arms simultaneously, then "send" the signal to the next section over, launching a phenomenon that can persist for quite a long time, circling the stadium many times. There ought to be a version that a stadium full of seismologists could do, simulating the several types of seismic waves in a visceral way. (No doubt there's a blog post somewhere already.)
Jon Lebkowsky (jonl) Wed 11 May 11 06:17
As Andrew noted Monday, we're at the end of the "official" two week run for this conversation. The next Inkwell conversation begins today, but this conversation doesn't have to end as long as Andrew and other are interested in continuing. In fact, I just ran across a couple of news stories referring to a prediction that Rome will have a significant earthquake today - many people are leaving Rome, per http://www.bbc.co.uk/news/world-13357963. That might be worth discussing, especially if there really is a severe earthquake in the region today (as predicted by the late Raffaele Bendandi, who didn't really pinpoint Rome). Many thanks to Andrew and Mark for this informative, in-depth discussion of earthquake and geology. This was an unusual discussion in that we didn't have a book to focus on, but maybe one will emerge in the wake of these discussions...
Andrew Alden (alden) Wed 11 May 11 11:50
No book, but my long-standing website at About.com <http://geology.about.com/> amounts to one. I do my best to cover earthquakes, volcanoes, tsunamis, rocks, minerals and the more advanced topics in geology at a layperson-friendly level. And of course I'm around the Well along with other folks with plenty of their own expertise, ready to comment whenever something comes up. If I have any advice today, it is to resolutely ignore and counterargue stories like the supposed quake prediction for Rome. Earthquakes, and the prospect of earthquakes, bring out the worst in people because they cannot be controlled and cannot be predicted yet. We give them the same responses we give to the prospect of death, taxes and other inevitabilities.
Alan Fletcher (af) Wed 11 May 11 11:54
[ slip -- for non-well people, that means <alden> posted <122> while I was composing this one. ] 1 dead after earthquake hits Spain <http://www.cnn.com/2011/WORLD/europe/05/11/spain.earthquake.death/index.html?h pt=T2> [ Thanks for the discussion --- maybe you can come back to it when there's a new event! ] < A magnitude 9 event is particularly good at exciting the extremely slow oscillations that affect the entire planet. Wouldn't this lend some credence to the triggering of related earthquakes, for example Simon Winchester's theories (and reports of a sequence of major quakes before the SF 1906 event).
Andrew Alden (alden) Wed 11 May 11 12:02
Any connections between great events and later ones that they may trigger are obscure and limited at best. Winchester is not a theorist, does not have a good grasp of his subject, and doesn't express himself well except as a barstool yarn-spinner. He really deserves the same share of attention as the predicters, which is to say none.
Gail Williams (gail) Wed 11 May 11 12:30
Thanks, Andrew and all. For WELL-members who enjoyed this, you might add the <quake.> conf to your list. (It's quiet for a while, then all of a sudden it's active and fascinating again. No wonder.)
Members: Enter the conference to participate