quote:The 8.8 magnitude earthquake that struck off coastal Chile in the early hours of the morning is one of the biggest temblors anywhere in more than a century.
Data from the U.S. Geological Survey suggests that this morning's Chile quake tied in fifth place with an 8.8 quake that hit Ecuador and Bolivia in 1906. Only four quakes have been bigger since 1900. The largest was a 9.5 magnitude event that struck Chile in 1960, causing 1,655 fatalities, leaving 2 million homeless, and triggering a tsunami that killed people in Hawaii, Japan and the Philippines.
"This was a big one," said Harley Benz, scientist in charge of the USGS's National Earthquake Information Center in Golden, Colo., which monitors global quake activity in real time. "The Chile quake released 500 times more energy than the quake that hit Haiti."
As far as the death toll, it seems to be around a hundred or so confirmed at the moment.
Meanwhile, A tsunami warning has been issued in Hawaii, and possibly parts of southern California. Not too sure about other parts of the pacific yet. The first waves are expected to start hitting Hawaii island in about 10-15 minutes, from what my parents told me. They aren't expecting waves more than a few meters, though.
[ April 05, 2010, 04:54 PM: Message edited by: Juxtapose ]
Posted by Mucus (Member # 9735) on :
Man, I was just reading this excellent article by BBC on the Haiti, Chinese, and Italian earthquakes. Crappy.
Posted by BlackBlade (Member # 8376) on :
quote:Originally posted by Mucus: Man, I was just reading this excellent article by BBC on the Haiti, Chinese, and Italian earthquakes. Crappy.
Stop watching TV Mucus, NOW!
Posted by Juxtapose (Member # 8837) on :
Wow, this has been a really bad couple of years for quakes. Is this worse than usual, or does it just feel that way because of the media light that shines a lot more on individual catastrophes?
Posted by ricree101 (Member # 7749) on :
If the lists are complete, then there definitely were a lot more 8 and up earthquakes this decade than there were the past couple decades.
I can't speak for the accuracy of that list, though.
Edit:
Of course, location can matter just as much as strength. The Haiti quake was only a 7.0, but caused much greater loss of life than this 8.8 seems to have.
[ February 27, 2010, 05:29 PM: Message edited by: ricree101 ]
Posted by ricree101 (Member # 7749) on :
If the lists are complete, then there definitely were a lot more 8 and up earthquakes this decade than there were the past couple decades.
Heh, Ricree, let's not start making scientific hypotheses based on research collected from wikipedia.
There were likely not a statistically aberrant number of earthqakes in the last decade. Wikipedia skews towards the reporting of recent events, with strong Anglocentrism, Amerocentrism, and Eurocentrism. What is notable on wikipedia is not necessarily important for any other reason than that it is more recent, and there exist more easily cited sources. Since the majority of wiki editors cite only online sources, events that are written about online are most likely to be included in articles, and therefore, there is likely to be 10 times as much citation of recent events than historical ones, with the exception of popular historical subjects.
What that means is that the fact that there are 5 earthquakes listed in 1998 and 5 listed in 99, and then another 80 listed in the last 10 years is not indicative of any actual geological pattern.
Posted by The White Whale (Member # 6594) on :
It seems like for the past 30 years, there have been 0, 1, or 2 earthquakes with a magnitude higher than 8.0, with 2007 being the only exception (with 4). The average is 1. There have already been 2 this year.
Magnitude 7 - 7.9 : between 5 and 18 earthquakes in any given year between 1980 - 2010. The average is 17.
Magnitude 6 - 6.9 : between 85 and 183 earthquakes in any given year between 1980 - 2010. The average is 134.
And here is a list of the deadliest earthquakes since 1900, sorted by number of deaths.
The top 10 years are: 1976, 2004, 2010, 1920, 1923, 1948, 2008, 2005, 1908, 1970.
Posted by Orincoro (Member # 8854) on :
I would only add to that that you need to take into account the rise in population over that period, particularly in the third world. The largest death tolls have been in developing areas of third world countries, many of which have seen their populations double and triple in that time span.
Posted by Juxtapose (Member # 8837) on :
I've wondered recently if the melting of the polar ice caps could increase seismic activity. That's quite a bit of weight redistribution. Unfortunately I haven't been able to find any research on the topic. I'm not even really sure how you'd study it.
Posted by Ron Lambert (Member # 2872) on :
Juxtapose, you might want to research the subject under the heading "isostasy."
quote:Isostasy Equilibrium in the Earth's crust, in which an elevated part in one area is counterbalanced by a depressed part in another. Isostasy exists because the Earth's crust is relatively light compared to the denser mantle over which it lies, and therefore behaves as if it is floating. Areas of the Earth's crust rise or subside to accommodate added load (as from a glacier) or diminished load (as from erosion), so that the forces that elevate landmasses balance the forces that depress them.
That does not obviate the possibility of consequent Earthquakes. I think Jux already knew the crust would resettle on the mantle with a weight distribution- the question is whether the redistribution of weight can trigger quakes.
Posted by Nighthawk (Member # 4176) on :
(It's satire... but very believable satire...)
Posted by King of Men (Member # 6684) on :
Poisson distributions. The number of high-magnitude earthquakes per decade is sufficiently low that the variance is very high compared to the value. (Even more so when you consider the number that hit in populated regions.) Compare the classic V1-impacts-in-London thing.
Posted by Juxtapose (Member # 8837) on :
quote:Originally posted by Orincoro: That does not obviate the possibility of consequent Earthquakes. I think Jux already knew the crust would resettle on the mantle with a weight distribution- the question is whether the redistribution of weight can trigger quakes.
Basically. I'm always happy to learn a new word though. Posted by Raymond Arnold (Member # 11712) on :
quote:(CNN) -- The massive earthquake that struck Chile on Saturday may have shifted the Earth's axis and created shorter days, scientists at NASA say.
The change is negligible, but permanent: Each day should be 1.26 microseconds shorter, according to preliminary calculations. A microsecond is one-millionth of a second.
A large quake shifts massive amounts of rock and alters the distribution of mass on the planet.
I'm assuming that this isn't actually that weird for an quake of that magnitude, and that this sort of thing has happened before, we just haven't been able to measure it until relatively recently.
But between this and Haiti (and on a smaller but more local scale, the huge snowstorm that caused a power outage for 90,000+ people in my area), I feel like Nature is giving us a not-so-gentle reminder that she is orders of magnitude more badass than we are.
Posted by Mucus (Member # 9735) on :
Ah, newspaper comments
quote:Should tickle the Obama administration if the day is shorter they will have their tax people in our pockets quicker and they can figure ways to spend more money.
quote:Maybe if the day is shorter and it screws up the electronics there will be less junk stuck in peoples ears and eyes so they can see the road better.The scariest thing in the world is to see someone looking straight at you at an intersection and have a cell phone stuck in their ear and no not what the devil they are going to do next.
quote:It just means that my credit card bills will arrive earlier.
Posted by Orincoro (Member # 8854) on :
quote:Originally posted by Raymond Arnold: I'm assuming that this isn't actually that weird for an quake of that magnitude, and that this sort of thing has happened before, we just haven't been able to measure it until relatively recently.
This is not a measurement based on observation, it's a projection- meaning that it assumes this happens with all similar quakes. Don't worry though- the Earth's rotation is augmented and retarded constantly by seismic events and extraterrestrial forces- particularly the other planets. The variations are routinely larger than this one, and they are constant.
Posted by Mucus (Member # 9735) on :
I was in Taiwan during a slight tremor. For some reason because I was at the top of a tall building it felt like the roof was swaying back and forth. It was definitely an adrenaline rush.
Posted by Juxtapose (Member # 8837) on :
I've been on the ground in an earthquake and that's what it felt like. I can imagine it being a bit more disconcerting on a roof.
Posted by Mucus (Member # 9735) on :
quote:Search operations have been called off in eastern Turkey after an earthquake claimed scores of lives in six villages.
The government said 51 people had been killed and dozens hospitalised after the quake struck in Elazig province early on Monday.
About eight hours after the 6.0 magnitude quake, the search for victims ended.
Okay, not a very big one, not a big deal. All these recent earthquakes are a pretty freaky coincidence. I was listening to a report on NPR about how one earthquake can't possibly transfer enough energy across the globe to create an earthquake across the planet, but I'm starting to wonder if there's a single point causing them all, rather than them affecting each other. But then, what do I know about seismology? Almost nothing.
What I think is most likely, is that we've been hit with a coincidental series of large earthquakes, and the hysteria has caused the media to overhype several smaller quakes that normally wouldn't receive any or nearly as much coverage as they are. So it feels like we're surrounded by quakes, building up to the conclusion of a made for TV SyFy movie.
Posted by Hobbes (Member # 433) on :
quote:What I think is most likely, is that we've been hit with a coincidental series of large earthquakes, and the hysteria has caused the media to overhype several smaller quakes that normally wouldn't receive any or nearly as much coverage as they are. So it feels like we're surrounded by quakes, building up to the conclusion of a made for TV SyFy movie.
Yes.
Hobbes Posted by Jake (Member # 206) on :
Several years ago I subscribed to the USGS earthquake alert email notification system, and set my threshold such that I would get notified anytime there was an earthquake of greater than 5.0 magnitude anywhere in the world. I haven't seen an increase in the number of earthquakes lately.
Posted by DarkKnight (Member # 7536) on :
quote: So it feels like we're surrounded by quakes, building up to the conclusion of a made for TV SyFy movie.
I hope not...those movies are completely AWFUL! SyFy can make a great series, but terrible terrible movies
Posted by aspectre (Member # 2222) on :
The entire city of Concepcion was moved ~10feet (303.9centimetres) to the west by the earthquake. And SouthAmerica was expanded by ~9feet11inches (3metres) between Concepcion,Chile and BuenasAires,Argentina.
Lawyers are gonna have tons of fun defining the new property lines.
Posted by aspectre (Member # 2222) on :
quote:Roads were torn up, buildings cracked and electricity posts toppled on Monday after a 7.2 magnitude earthquake shook cities in northern Mexico and Southern California, but few casualties were reported.
Mexican civil protection officials said at least one man died in a collapsed house and about 100 more were injured in Sunday's quake.
More earthquake (almost certainly doesn't mean anything, but still a little creepy)
Posted by Jhai (Member # 5633) on :
Well, it's not really related to the Chile earthquake, but it suggests bad news for California proper might be coming up.
Posted by Lyrhawn (Member # 7039) on :
Maybe we need a general earthquake thread.
Posted by Juxtapose (Member # 8837) on :
I'll change the thread's title.
Posted by Samprimary (Member # 8561) on :
quote:Originally posted by Lyrhawn: Maybe we need a general earthquake thread.
What, is 2012 coming up already?
Posted by Lyrhawn (Member # 7039) on :
It's never too early to plan for the apocalypse.
Posted by Juxtapose (Member # 8837) on :
Planning for the Apocalypse checklist:
1. Make a thread on Hatrack.
Posted by Mucus (Member # 9735) on :
quote:A major earthquake of 7.7 magnitude struck off the coast of Aceh on the Indonesian island of Sumatra on Wednesday, but there were no immediate reports of casualties.
quote:Originally posted by Jhai: Well, it's not really related to the Chile earthquake, but it suggests bad news for California proper might be coming up.
Not really. The Big One is probably happening some time in the next 30 years.
Just like last week.
Posted by Lyrhawn (Member # 7039) on :
Aren't you guys overdue? I can't remember the average length for when big ones hit California, but the last one was what, a hundred years ago? And they come every hundred or so years don't they?
Posted by rivka (Member # 4859) on :
They've been saying "sometime in the next 20-30 years" for about 15 years now.
And no, there is no "every 100 years" pattern.
Posted by Lyrhawn (Member # 7039) on :
Is there any pattern? How else would they guess when the next one is expected?
Posted by rivka (Member # 4859) on :
IIRC, many years of measurements, showing quite a bit of stress on the relevant faults.
Posted by rivka (Member # 4859) on :
Assessing seismic risk is a rather controversial (within the profession) and in-exact thing. We really can't measure very much that directly relates to earthquake activity and are just making guesses. The amount of differential motion between plates is something (though we haven't been able to do that very accurately until pretty recently) but most of the maps are actually based almost entirely on past history of earthquakes. If you cared enough to look (and I don’t know why you would) you’d see a change in the maps every time there’s an earthquake, and then general changes every so often to account for all the little ones (I can’t remember how often they do these). There’s a relatively high seismic rating around New Madrid (a bit south of St. Louis) despite the fact that we can’t really “see” any fault lines there. Recently there have only been small earthquakes in the area, but in the early 1800s there was a very, very large quake and so the maps show a high seismic zone. It’s a problem: some faults generate large earthquakes infrequently where others generate small earthquakes constantly (so to speak), and then some do both. There’s really no way to tell what any particular fault is other than looking at the historical record and our data just doesn’t go far enough back to be sure of anything (particularly in the US). If the New Madrid earthquake had happened 50 years, or especially 100 years earlier all our seismic maps would be different, but obviously nothing would be different about the actual danger posed by the fault.
The links Rivka posted are very good descriptions, but California is actually an aberration from the remainder of the country. Basically they both set the standard, and then grandfathered in the parts that didn’t make the national standard. They’ve been dealing with the problem longer than anyone else so they rely a lot on past experience. The way the national earthquake codes work is based on the ‘Maximum Considered Earthquake’, or MCE which is about once every 1500 years. We have about 100 years of reliable data, and even that isn’t very complete. Even California’s code is really based on the MCE, but with grandfathered in clauses referring to this 50 year exceedence stuff (the technical specs come out literally identical, they just get to use different language). Trying to predict the largest ground motions possible for 1500 years (when these things are highly variable as is, it’s not like you’d actually be sure you saw it every 1500 years) with 100 years of data is kind of a farce. But you’ve got to base it one something and this is the best we’ve got.
Hobbes Posted by Lyrhawn (Member # 7039) on :
Thanks for the links rivka, and the explanation, Hobbes. That was very informative (and interesting!). I wonder if I was confusing quake predictions with eruption predictions for volcanoes. But now I'm not even sure about that. I don't suppose we have a resident vulcanologist in addition to seismologist?
Either way I'm happy to know more today than I did yesterday.
Posted by Mucus (Member # 9735) on :
quote:Chinese media say at least 67 people have died and others are trapped under rubble in Qinghai province after an earthquake said to be magnitude 6.9.
The quake struck at 0749 (2349 GMT) 380km (240 miles) south-south-east of the city of Golmud, at a depth of 10km, according to US Geological Survey data.
Ok, who turned up the Rim of Fire?
Posted by Mucus (Member # 9735) on :
Does Qinghai count as being on the Ring of Fire?
Anyways, news update:
quote:A series of deadly earthquakes – the biggest registering 6.9 – ripped through a remote region in southwestern China Wednesday killing hundreds and injuring thousands.
State media reported at least 400 had died and between 8,000 and 10,000 were injured as the Chinese government mobilized rescue efforts to reach to the remote area of Yushu county in Qinghai province.
quote:Originally posted by Mucus: Does Qinghai count as being on the Ring of Fire?
Close, no?
And updated reports I'm seeing say it was actually 7.1. Edit: Ah, that's what the Chinese government is saying; the USGS says 6.9.
Posted by Mucus (Member # 9735) on :
I don't actually know what close is in this context. But totally eye-balling it, Qinghai is as close the Ring of Fire here as is Manitoba or whatever US state is directly south of Manitoba.
Posted by Juxtapose (Member # 8837) on :
Reported death toll is over 600. Posted by Mucus (Member # 9735) on :
Explanation:
quote:"Many women who do not dress modestly lead young men astray and spread adultery in society which increases earthquakes," he said.
It's not fair. Why do they make women cover themselves up to protect young men, but I'm still forced to live in a world with a buff and shirtless Hugh Jackman?
Posted by aspectre (Member # 2222) on :
Hence the translation Cali -- Hot forni - sex a ----- land
And the state motto, "Didja feel the earth move, baby?"
[ April 21, 2010, 09:17 PM: Message edited by: aspectre ]
Posted by Mucus (Member # 9735) on :
Great, earthquakes in Ontario now. Stupid G20
Posted by Juxtapose (Member # 8837) on :
Everyone in SoCal okay?
Posted by rivka (Member # 4859) on :
Seems like. Really felt those p-waves, though. (I think those are the ones that can trigger nausea, no?)
Posted by Lyrhawn (Member # 7039) on :
It's 200 miles further out than the one that killed so many in Banda Aceh. Looks like about an hour ago the tsunami warning went out, so people are headed for the hills. Some places are getting predictions of waves several meters high. It's not as powerful as the Banda Aceh quake from years ago or the Japan quake from last year, but it's still a biggie.
Update: Despite the tsunami warning, a rep from the US Survey says a tsunami is unlikely given the type of earthquake.
Posted by Lyrhawn (Member # 7039) on :
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