Stop plate tectonics!!

June 16, 2005 2:32 PM

Is there a big earthquake in California's near future?

There have been three earthquakes over 5 on the Richter Scale in California in the last week, two in Southern California. As a jumpy little fella living in Los Angeles, I'm worried that this a predilection of worse things to come. Or is it just the earth letting off steam? I know that no one can predict this stuff, but are there any seismologists out there who want to give it a shot?

posted by billysumday to science & nature (27 comments total)

Jeez, how long have you lived in California? It's only a couple of earthquakes. That said, I'd really like to see Southern California fall into the sea. (Leaving the cool, crisp serenity of Arizona Bay.)
posted by keswick at 2:35 PM on June 16, 2005

Not very long at all.
posted by billysumday at 2:36 PM on June 16, 2005

Real-Time Forcast of Earthquake Hazard in the Next 24 Hours.
posted by karmaville at 2:40 PM on June 16, 2005

On the geological scale (near future = next 1-2000 years), yes.
posted by matildaben at 2:45 PM on June 16, 2005

Sorry, keswick, Southern California is moving horizontally rather than vertically. And in the transverse regions, it's actually moving UP.

Billysumday: Of course there is a big earthquake in California's near future, speaking on a geologic scale. On a human scale? No one can say. Both Los Angeles and San Francisco are going to get the crap kicked out of them by earthquakes. But if it is tomorrow or in 50 years we cant say.
posted by Justinian at 2:47 PM on June 16, 2005

Every time there's a quake out here, one of my midwestern family members and/or friends calls to ask me whether it was an aftershock or a pre-quake. I'd like to know how they know so much about my weather, dammit. Go chase your tornados, oakies!

I'm not worried at all.
Say, have you noticed those disaster packs they've had on sale at Von's? They look sporty.

[takes another stiff drink, flings self under doorframe at sound of passing truck, falls asleep with on floor with shoes on.]
posted by maryh at 2:50 PM on June 16, 2005

You'll find what you're looking for at the bottom of this page:
http://earthquake.usgs.gov/hazards/probability.html

Wonderful, heart-warming stuff.
posted by _sirmissalot_ at 3:01 PM on June 16, 2005

Throughout my lifetime, seismologists have appeared in the news every year or so to say The Big One is thirty years away. Given my age, that means it should have happened within the last couple of years.

You have got to be new around here if a couple of dinky temblors in a week makes you fret. Welcome to California! This really is what it's like sometimes.
posted by majick at 3:07 PM on June 16, 2005

It's raining in San Francisco for the next couple of days. So it's not earthquake weather, so we're fine.
posted by Nelson at 3:09 PM on June 16, 2005

I'm watching Channel 4 now and it's really cool. They're letting a scientist explain stuff for minutes on end. An articulate scientist! It's great tv.
posted by rdr at 3:10 PM on June 16, 2005

Also, it seems that while general predictions can be made for a decades-long time scale, the kind of predictability you seek does not exist:

"Empirical earthquake prediction would require the existence of observable and identifiable precursors [HN18] that would allow alarms to be issued with high reliability and accuracy. There are strong reasons to doubt that such precursors exist (10). Thousands of observations of allegedly anomalous phenomena (seismological, geodetic, hydrological, geochemical, electromagnetic, animal behavior, and so forth) have been claimed as earthquake precursors, but in general, the phenomena were claimed as precursors only after the earthquakes occurred . . .

. . . Whether any particular small earthquake grows into a large earthquake depends on a myriad of fine details of physical conditions throughout a large volume, not just in the immediate vicinity of the fault (7). This highly sensitive nonlinear dependence of earthquake rupture on unknown initial conditions severely limits predictability (8,9). The prediction of individual large earthquakes would require the unlikely capability of knowing all of these details with great accuracy. Furthermore, no quantitative theory for analyzing these data to issue predictions exists at present. Thus, the consensus of the meeting was that individual earthquakes are probably inherently unpredictable."
posted by _sirmissalot_ at 3:13 PM on June 16, 2005

Do those midwestern relatives live near the Madrid fault, maryh? That's where the action's going to be for a U.S. earthquake racking up a huge death toll -- at least in CA, a lot of things (if far from all) have been built to withstand quakes.
posted by Zed_Lopez at 3:15 PM on June 16, 2005

I'd like to know how they know so much about my weather, dammit.

I was in Silicon Valley on business the other night but my mom in Seattle knew about the northern California quake before I did. Quakes in California seem to get a lot of news coverage around the country. Probably some combination of lots of people know people or have relatives in California and schadenfreude.

Or is it just the earth letting off steam?

I've read that having a number of relatively small earthquakes is better than the faults building up stress until there's a really big earthquake, so the occassional 5.0er is probably better than years of calm followed by a 10.0.
posted by blm at 3:30 PM on June 16, 2005

And now for your daily dose of synchronicity...
posted by blm at 3:37 PM on June 16, 2005

Short answer: Probably, if we define "near" to be within the next thirty years or so. That earthquake, when it comes, will probably have little to do directly with these recent earthquakes.

Long answer: First off, these three quakes are unrelated to each other as they occurred on different fault systems. The two SoCal earthquakes might be tangentially related - it's possible that the release of energy on one fault system caused an increase in pressure on the other, but this is not certain. You can safely expect aftershocks of each quake on their respective fault systems, but you can't reliably predict when the next large quake will strike based on these events. The patterns of stress accumulation and release are still being worked out, and as _sirmissalot_'s link says, it's near impossible to know all the details of the conditions leading to a fault rupture. The earthquakes did release some of the stress on the fault systems involved, though, so it's not inaccurate to say that the "earth's just letting off steam".

Secondly, it's not at all unusual to have this many earthquakes of this size relatively close to each other in a short period of time. Statistically, seismologists expect about 17 magnitude 7 earthquakes per year, and over 1300 magnitude 5 earthquakes worldwide. So for two of those 1300 to occur close to each other in space and time isn't improbable.

As majick points out, they've been saying for years that "the Big One" is on its way, and it's guaranteed that at some point in the future there will be devastating quakes in both the Los Angeles and San Francisco metropolitan areas. Just a fact of life in California. The best thing you can do is make sure you're prepared for it, and once you've done that, try not to worry about it too much. Every region has its hazards; earthquakes just happen to be ours.
posted by Aster at 3:39 PM on June 16, 2005

blm, for us in the Pacific Northwest it certainly is schadenfreude (damn Californians driving up property prices) and the fact that the tsunami warnings set off the EAS and interrupted radio and TV.
posted by karmaville at 3:42 PM on June 16, 2005

Oh, they've been going on about "the big one" sometime "soon" in Seattle/Puget Sound region too. We're not going to get away.
posted by matildaben at 3:50 PM on June 16, 2005

Probably some combination of lots of people know people or have relatives in California and schadenfreude.

Mostly shadenfreude, I think. Even the local news in Chicago reports every wildfire, flood and temblor that hits SoCal. The belief that California deserves to crumble under the ocean waves is precious to a certain percentage of the population (and obviously not just in the Windy City.)

Thanks for the link, Zed_Lopez. I'll be sure to bring the Madrid Fault up next time the relatives ring.
posted by maryh at 4:10 PM on June 16, 2005

billysumday...if you are jumpy, then the best thing you can do is learn what to do during an earthquake. Get under something sturdy (a table is better than a doorway, imho), face away from glass, cover your head, and don't leave until the ground has completely stopped shaking. Your biggest danger is getting hit by a falling object.

Earthquake building codes are pretty strict in CA. Buildings can withstand pretty strong shaking.

blm: There's a huge magnitude of difference between a 5.0 and 7.0 earthquakes. A few 5.0s is insignificant compared to a 7.0. According to this site (link to follow), a 5.0 earthquake is roughly equivalent to 32,000 tons of TNT. A 7.0 earthquake is 32 *million* tons.
http://www.seismo.unr.edu/ftp/pub/louie/class/100/magnitude.html

In short, earthquakes are a part of life in SoCal. Yes, they can be devastating, but these are rare. Most earthquakes you'll never feel. And most that you do won't cause any damage.

Personally, I'll take the occassional earthquake over the tornados or hurricanes that seem to regularly plague some parts of the US.
posted by luneray at 4:43 PM on June 16, 2005

The belief that California deserves to crumble under the ocean waves is precious to a certain percentage of the population (and obviously not just in the Windy City.)

I think it's just Southern California crumbling under the ocean waves that is appealing.
posted by keswick at 5:04 PM on June 16, 2005

blm writes "And now for your daily dose of synchronicity..."

I'm guessing that's not so much synchronicity as it is the direct inspiration for this question. billysumday posted about 40 minutes after that quake.
posted by mr_roboto at 5:11 PM on June 16, 2005

This was a very interesting article in San Francisco magazine from a couple months ago, talking about "it's not if, it's when," and how completely unprepared we are for the next Big One. In case your midwest or east coast relatives need something else to worry about.
posted by bendy at 5:54 PM on June 16, 2005

To everyone who gets schadenfreude at the idea of Southern California being destroyed: I'll be sure to make gloating comments when you or your loved ones die. Perhaps of cancer or some other horrible disease. Thank you.
posted by Justinian at 6:22 PM on June 16, 2005

"Terrorism is an if. Earthquake is a when."

Thanks, bendy!

I'm so the fuck out of California.
posted by _sirmissalot_ at 6:35 PM on June 16, 2005 [1 favorite has favorites]

blm, for us in the Pacific Northwest it certainly is schadenfreude (damn Californians driving up property prices) and the fact that the tsunami warnings set off the EAS and interrupted radio and TV.

If "the big one" actually happens within the next 10 or 20 years, we might not want to be putting on our gloating caps on just yet.
posted by cmonkey at 6:59 PM on June 16, 2005

I think it's just Southern California crumbling under the ocean waves that is appealing.

Keswick, for the people outside California who see this state as a metaphor for 'bad' culture, there's no north or south. It's just California, and it belongs underwater.
(I've gotten attached to this place, but I'd be willing to give up Irvine. And Barstow. Mainly Barstow.)
posted by maryh at 7:06 PM on June 16, 2005

Now that there's been a likely aftershock to that NorCal quake, there's an interesting article in the LA Times about the closeness of these recent earthquakes:

Officials said Southern California usually experiences quakes of this magnitude several times a year, but acknowledged that it's rare for them to occur so close together.

"It is unusual. But we've seen it before," said Caltech seismologist Kate Hutton, noting that quakes often come in clusters over periods of years — a phenomenon that scientists cannot fully explain.

The series of earthquakes was enough to revive anxious chatter Thursday of the coming Big One, a massive quake along the San Andreas fault. Hutton and other experts said they can understand the concern.

"I can empathize why people feel that," added Lucy Jones, the scientist in charge of the U.S. Geological Survey's Southern California office. "We don't handle randomness well. We like to make patterns. The chances are we expect two 'fives' in a week once every 10 years. It's been very quiet. During the '80s, we had earthquakes every day from 1987 to 1994. People are out of habit. They've been lulled down."

posted by Aster at 7:31 AM on June 17, 2005