earthquakes
greengabbro | March 17, 2009A friend of mine IMed me this weekend, very excited about a minor earthquake. She used the word "temblor" and was very excited about that, too - how often do you get a chance to say "temblor"? She felt impressive and sciencey.
I have been hanging around with seismologists for some time now, and I don't think I have ever heard anyone use the word "temblor" in either ordinary or technical speech. I have only ever seen it in news reports, where it seems to fulfill a need to (a) limit the number of times a single word is repeated in a short space, and/or (b) use short words in headlines to…
greengabbro | March 2, 2009Once again it is time to acknowledge that I will never read all of the papers I've flagged in my RSS reader... but I can at least go through the abstracts. While my summaries here may be slightly in error due to the fact that I haven't actually read the papers in question, here is what I'm skimming:
Clay might trigger earthquakes - Many clay minerals break down, when heated, to produce H2O + different clay minerals. If this water is produced inside a clay-lined fault zone, and not allowed to leave, it might weaken the fault enough to produce an earthquake (cf. the beer can experiment).…
greengabbro | January 29, 2009One of my New Year's blogolutions was to clear out my to-blog folder, and bring closure to my unfinished drafts by simply posting them as-is. This is one of those drafts. Disorganized paragraphs, unfinished sentences, and general incoherence enhance the natural character and beauty of a half-written blog post and should not be considered flaws or defects.
Draft date: January 23, 2008
A powerful earthquake measuring 7.7 on the Richter scale ripped through northern Chile today, causing panic, power outages, damage to airport tarmacs and road closures, according to news reports.
I wince every…
greengabbro | January 15, 2009One of my New Year's blogolutions was to clear out my to-blog folder, and bring closure to my unfinished drafts by simply posting them as-is. This is one of those drafts. Disorganized paragraphs, unfinished sentences, and general incoherence enhance the natural character and beauty of a half-written blog post and should not be considered flaws or defects.
Draft date: August 15, 2008
At about 2 in the morning on Saturday night, I was wandering back to the hotel when I found myself chatting with someone on the street. I have no idea how the conversation got onto earthquakes, but it did, and…
greengabbro | January 12, 2009I've been working on a set of scripts that will play sped-up seismograms as sound. I was very proud of myself last night for remembering enough Perl to translate from one format to another, thereby producing clicking noises. Obviously I'm still doing something wrong in the processing necessary to translate from a 10 minute seismogram, recorded at 50 samples/sec to catch interesting stuff that happens at frequencies well below the range of human hearing, to a 5 second audio clip played back at ten thousand or so samples/sec... but hey, clicking noises are better than nothing!
Then I found that…
amillikan | January 4, 2009Since December 26, seismologists have observed over 400 seismic events at Yellowstone National Park—a record number of earthquakes for the hot spot which houses the largest supervolcano in North America. Data is still being analyzed to determine what this "swarm"—a sequence of earthquakes similar in magnitude—could mean. ScienceBlogger Greg Laden will be following the events closely on his blog.
greengabbro | January 2, 2009If you like apocalypse porn, you have probably been following the current earthquake swarm at Yellowstone. While there is no reason to believe that this is part of the lead-up to a giant caldera-forming eruption that will wipe out most of North America, or indeed to any eruption at all, there is also no reason to let that spoil your fun.
If you're watching the recent earthquakes page, take the reported earthquake depths with an especially big piece of salt. Earthquake depth is difficult to accurately determine, especially with real-time automated processing techniques. Think about it: You've…
awild | December 30, 2008There are days when I wish I hadn't read Bill Bryson's A Short History of Nearly Everything.
Today is one of them.
greengabbro | December 18, 2008According to a study of deaths from natural hazard "events"* across the U.S., earthquakes, volcanoes, and other spectacular geophysical hazards are much less deadly than common weather events like heat waves, floods, and thunderstorms. The study was published in the open-access International Journal of Health Geographics, so you should all be able to follow the link - but if you would rather read the summary version, the Los Angeles Times noticed that California is mostly safe, and ran with that angle.
The study's authors looked at county-level data on natural fatality hazards during the…
greengabbro | July 14, 2008 There's an article in last Friday's issue of Nature describing some changes in the rocks near the San Andreas Fault that occurred in the hours before two small earthquakes. Here's the BBC's writeup; for those of you who can sneak behind the Nature paywall, the original article is here.
A similar study was published sixteen years ago, not in Nature but in Science. The first author on the 1992 Science paper, Paul Silver, was also the second author on this week's Nature paper. While the recent study measured stress changes along a fault using precise instrumentation installed in a pair of very…
greengabbro | July 11, 2008 Well, technically this is Friday tsunami blogging, but sometimes it's hard to tell the difference. Yesterday was the 50th anniversary of the 1958 Southeast Alaska earthquake and ensuing Lituya Bay megatsunami, a half-kilometer high wave which killed only a handful of people.
The earthquake happened on the Fairweather fault, a strike-slip fault which forms the main boundary between the Pacific and North American plates on the Alaska panhandle. Strike-slip earthquakes don't typically cause tsunamis directly - in a strike-slip event, the ground moves mostly horizontally, not vertically, so it…
greengabbro | June 27, 2008I've finally read Dr. Tom Chalko's wackaloon manuscript. It was fantastic.
Chalko artfully combines common misconceptions about his subject matter with accessible yet impressively mathy-lookin' slipshod data analysis, and produces an argument that appeals to the innate human desire to make sense of the natural world. His skill at subtly invoking people's fear of a changing world and appropriating the power of existing cultural narratives - in this case, the discourse on climate change - places him among the crackpot screed-writing elite. That makes it worth discussing a few of his more…
greengabbro | June 19, 2008This is the most irresponsible "science" "reporting" I have seen in yonks:
New research compiled by Australian scientist Dr. Tom Chalko shows that global seismic activity on Earth is now five times more energetic than it was just 20 years ago.
The research proves that destructive ability of earthquakes on Earth increases alarmingly fast and that this trend is set to continue, unless the problem of "global warming" is comprehensively and urgently addressed.
Cursory examination reveals that Dr. Tom Chalko is a complete wackaloon! Even if you do not know the first thing about seismology,…
greengabbro | June 12, 2008Earthquake engineer Kit Miyamoto has posted a journal of his trip to Sichuan. If you don't mind a little bit of construction jargon it's a good discussion of the details of what kinds of buildings collapse, and what kinds are safe, as well as the logistical difficulties of the immediate post-earthquake recovery. The lesson to be learned from the Sichuan earthquake is the same as the lesson of basically every major earthquake in the past several decades: If you build bad buildings, they will fall down and kill people.
After some earthquakes, we have been able to dramatically improve our…
greengabbro | April 19, 2008Every time there's an earthquake in the Midwest, my mother emails me, just in case I want to move back home to study it. So that's how I heard about yesterday morning's earthquake in Illinois - a bit less exciting than waking up to it, but that's fine with me.
This is not earthquake enough to reverse the geoscientific brain drain from the Midwest to the West Coast (there's also the weather to think about)... but for an ostensibly stable part of the continental interior, thousands of miles from the nearest plate boundary, Illinois and Indiana have seen an awful lot of seismic action over the…