Are these seismic events related?

October 13, 2009 10:54 AM

Are all of these seismic events related?

So there have been a bunch of big quakes on the west side of the Pacific Plate (Vanatu, Solomons, etc).

These seem to be continuing, but now there's a cluster of quakes on the North side along Alaska.

More interestingly, there's another swarm of quakes in Greece. I was looking at the RSOE map and noticed that Greece seems to be somewhat on the other side of the earth (not a straight line, but for eyeball purposes, close enough)

Are these seismic waves propagating? Does a big ole shake on one side of the earth sometimes bounce waves to the other?

And on more specific Pacific Plate things, is the plate rotating or simply sliding upwards?

Is it solid? Do those West-Side quakes change the overall shape of the plate which in turn caused the quakes in Alaska?

Or is this all a very inexact science where things just happens?

posted by Lord_Pall to Science & Nature (7 answers total)

The short answer: no one knows. There is lots of research on earthquakes and earthquake predictions and clustering and how past earthquakes effect future earthquakes and basically... no one knows. Hopefully the research is getting better and we're figuring it out more and more, but for now, your questions are just plain unanswerable, sorry.
posted by brainmouse at 11:06 AM on October 13, 2009 [1 favorite]

Well, the USGS says:

Q: Two earthquakes occurred on the same day. Are they related?

A: Often, people wonder if an earthquake in Alaska may have triggered an earthquake in California; or if an earthquake in Chile is related to an earthquake that occurred a week later in Mexico. Over these distances, the answer is no. Even the Earth's rocky crust is not rigid enough to transfer stress fields efficiently over thousands of miles.

There's probably a fuller, more nuanced discussion somewhere on their site, and perhaps some more directly related to your exact question but since I'm skiving off work right now and should really stop doing that (today, anyway!), I'll leave it to you to poke around to find it.
posted by rtha at 11:31 AM on October 13, 2009

Some people think that they are related.
posted by infinitefloatingbrains at 11:33 AM on October 13, 2009

This was featured on a recent Radio 4 program... I was only half listening but I think the jist was one quake didn't cause the other in the Pacific but they both may have the same underlying cause (whatever that is)
posted by fearfulsymmetry at 11:36 AM on October 13, 2009

Don't forget the recent rash of water main breaks in Los Angeles -- LA has now called in JPL to investigate whether it's due to increased seismic activity: "Examining the timing and location of the breaks, JPL scientists have noticed "some deviation from the normal range" of ground movement in L.A. in the last 100 days, said Andrea Donnellan, NASA headquarter's program area co-lead for natural disasters, who works at JPL."
posted by Asparagirl at 12:10 PM on October 13, 2009

More interestingly, there's another swarm of quakes in Greece.

We're having quakes? I didn't notice anything. Greece is a pretty active area seismically, the small magnitude quakes displayed on your map look like business as usual, and are probably imperceptible without a seismograph anyway.
posted by Dr Dracator at 2:25 PM on October 13, 2009

Scientists agree it is freaky, but are unsure of a cause.
posted by bystander at 7:58 PM on October 13, 2009