Are large earthquakes linked across the globe?

Aug 02, 2012

The past decade has been plagued with what seems to be a cluster of large earthquakes, with massive quakes striking Sumatra, Chile, Haiti and Japan since 2004. Some researchers have suggested that this cluster has occurred because the earthquakes may be "communicating" across large distances, possibly triggering each other. But a new analysis by Tom Parsons and Eric Geist of the US Geological Survey concludes that the cluster could just as well be the result of random chance.

Each of the devastating quakes in the 2000s drew huge and required extensive rebuilding and economic restoration. The intense interest in the earthquakes has led some to wonder if we are living in the middle of an "age of great quakes," similar to a global cluster of quakes in the 1960s. It's important to know whether these clusters occur because big earthquakes trigger others across the world, Parsons and Geist say, in order to predict whether more severely destructive quakes might be on the way.

To determine if the clusters in the 1960s and 2000s could be attributed to random chance, the researchers looked at the timing between the world's largest earthquakes--magnitude 8.3 and above--at one-year intervals during the past 100 years. They compared simulated lists of large quakes and the list of real quakes during this time with the between-quake intervals expected from a random process. The intervals between the real-life large quakes are similar to what would be expected from a , they found. In other words, the global hazard of large earthquakes is constant in time. Except in the case of local , the probability of a new large quake occurring isn't related to past global quakes.

This could be disappointing news for researchers who thought global communication between quakes might offer a way to predict the most severe . But there also may be some good news after a decade of destruction. If global great earthquakes are occurring at random, the authors say, then a specific number of quakes that cluster together within a short time is unlikely to be repeated in a similar way over a 100-year span.

Explore further: Karina's remnants drawn into Hurricane Marie's spin

More information: "Were Global M≥8.3 Earthquake Time Intervals Random between 1900 and 2011?" by Tom Parsons and Eric Geist of US Geological Survey. Bulletin of the Seismological Society of America

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User comments : 9

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rwinners
1 / 5 (1) Aug 02, 2012
The simple fact that large earthquakes occur in clusters is pretty good evidence, in the near term, that they do stimulate ongoing events. I seriously doubt that science has been able to date earthquakes accurately over a sufficiently long period of time to disprove that.
ishtarmuz
1 / 5 (1) Aug 02, 2012
Does not random imply independent events? If I flip a hundred heads on a fair coin, then the next flip is still 50% chance of another head. So to say that this cluster of earthquakes is both random and will not likely reoccur for another 100 years appears to be a contradiction. Unless we are saying is that mechanism of building the pressure for each "flip" is a hundred year event. Is that what the researchers are saying?
SatanLover
1 / 5 (3) Aug 02, 2012
there is no such thing as random in the absolute only in the relativity of the "stupid".
DarkHorse66
not rated yet Aug 03, 2012
What proportion of the massive earthquakes/named clusters would be found on or near the rim of fire?
http://en.wikiped..._of_Fire
It seems to me, quite a lot of them. If any area is more earthquake 'friendly' than elsewhere, this would be it.
That is the only connection that I would see as remotely likely to cause clustering between earthquake zones.
Best Regards, DH66
Yarking_Dawg
5 / 5 (3) Aug 03, 2012
uhm... Guys, if you don't know anything about statistics... might not want to advertise that with your comments.

The appearance of clustering is a feature of random events. If you flip a coin a hundred times, somewhere in that hundred it is almost certain you will see any 5 flip pattern you might imagine represents a cluster, including five heads or five tails in a row. Difficulty is sorting a random appearance of clustering from a cluster arising from a cause. To do that, you have to take every clustering possibility, calculate how likely it is to occur at random and compare that to the measured events to see if the measured events cluster beyond the random norm. If the clustering is sufficiently different than the random norm, then it represents an indication that there is likely some causal connection linking the events.
Zarabtul
1 / 5 (2) Aug 03, 2012
Yesw all seismic activity is related to seizure activity I proved that many years ago... Now my question is this....

Who the hell is messing with the mathematics we did in the Gulf to stop the Hurricanes from wiping the Southern Part of our country. I did not nearly get killed lose my wife and be tortured for years for you to come screw it all up now. Now I do want answers and I want them now.

Sincerely,

Gen. Andrew F. Strasser
A_Paradox
5 / 5 (1) Aug 03, 2012
Dawg
The appearance of clustering is a feature of random events. .. flip a coin a hundred times,...almost certain you will see any 5 flip ... Difficulty is sorting a random appearance of clustering from a cluster arising from a cause. To do that, you have to take every clustering possibility, calculate how likely it is to occur at random and compare .... If the clustering is sufficiently different then it represents an indication that .. likely some causal connection ..

thy careful reticence is laudable. :-) I think there is something missing from the discussion though. The article says nothing of how they are modelling the quakes nor does it mention anything about locations. I have seen the movement of tectonic plates on top of the Earth's mantle likened to movements of crusty stuff on the top of jam simmering in a pot. Can anybody model that stuff?

continued below:
A_Paradox
not rated yet Aug 03, 2012
Jam, etc, continued... It seems to me to be somewhat fatuous just creating mathematical models for the sake of it. AS economic theory seems to show, there is often a significant danger of unconsciously deciding that the mathematical model is more real than the range of events and/or protagonists that the model is purporting to represent.

I mean it is probably that these guys are really good at their stuff but maybe they are not using the right tools. Perhaps they should be constructing neural networks like the young lady recently in the US who created a system for analysing tumour biopsy images which is apparently 99% reliable in detecting breast cancers; those results are apparently way better than human experts have been so far.

Perhaps it is possible to make a neural network that can 'look' at videos of boiling jam and learn to make accurate predictions of timing of deformations of scum patches on the surface. :-)
?outside the square?
TheGhostofOtto1923
4.7 / 5 (12) Aug 03, 2012
Yesw all seismic activity is related to seizure activity I proved that many years ago... Now my question is this....

Who the hell is messing with the mathematics we did in the Gulf to stop the Hurricanes from wiping the Southern Part of our country. I did not nearly get killed lose my wife and be tortured for years for you to come screw it all up now. Now I do want answers and I want them now.

Sincerely,

Gen. Andrew F. Strasser
You sound pissed. I suggest moving to the california coast and collecting debris from the japanese tsunami for reselling. Not oregon as they are due a mag 8 pretty soon.

Just trying to help.