A global surge of great earthquakes from 2004-2014 and implications for Cascadia

October 21, 2014
Aerial photo of the San Andreas Fault in the Carrizo Plain, northwest of Los Angeles. Credit: Wikipedia.

The last ten years have been a remarkable time for great earthquakes. Since December 2004 there have been no less than 18 quakes of Mw8.0 or greater – a rate of more than twice that seen from 1900 to mid-2004. Hundreds of thousands of lives have been lost and massive damage has resulted from these great earthquakes. But as devastating as such events can be, these recent great quakes have come with a silver lining: They coincide with unprecedented advances in technological and scientific capacity for learning from them.

"We previously had very limited information about how ruptures grow into great earthquakes and interact with regions around them," said seismologist Thorne Lay of the University of California at Santa Cruz. "So we are using the recorded data for these recent events to guide our understanding of future earthquakes. We've gained a new level of appreciation for how one earthquake can influence events in other zones."

High on the list of areas ripe for a great quake is Cascadia, the Pacific Northwest, where the risk for great quakes had long been under appreciated. Evidence began surfacing about 20 years ago that there had been a great quake in the region in the year 1700. Since then the view of the great quake risk in Cascadia has shifted dramatically.

"We don't know many details about what happened in 1700," said Lay. There were no instruments back then to observe and record it. And so the best way to try and understand the danger and what could happen in Cascadia is to study the recent events elsewhere.

Over the last decade Lay and his colleagues have been able to gather fine details about these giant earthquakes using data from an expanded global networks of seismometers, GPS stations, tsunami gauges, and new satellite imaging capabilities such as GRACE, InSAR, and LandSAT interferometry. Among the broader conclusions they have come to is that great quakes are very complicated and idiosyncratic. Lay will be presenting some of those idiosyncrasies at the meeting of the Geological Society of America in Vancouver on Oct. 21.

"What we've seen is that we can have multiple faults activated," said Lay. "We've seen it off Sumatra and off Japan. Once earthquakes get going they can activate faulting in areas that were thought not physically feasible."

The great Sumatra-Andaman earthquake of Dec. 26, 2004, for instance, unzipped a 1,300 kilometer long segment of the subduction zone and unleashed one of history's most destructive, deadly tsunamis. Much of the rupture was along a region with very limited plate convergence. In Japan, the Kuril Islands, and the Solomon Islands, great mega-thrust ruptures have ruptured portions of the that were thought too warm or weak to experience earthquakes.

"These earthquakes ruptured right through areas that had been considered to have low risk," said Lay. "We thought that would not happen. But it did, so we have to adjust our understanding."

Perhaps the best recent analogy to Cascadia is off the coast of Iquique, Chile, said Lay. There had been a great quake in 1877, and a conspicuous gap in quakes ever since. Like the 1700 Cascadia , there is little data for the 1877 event, which killed more than 2,500 people. In both subduction zones, the converging plates are thought to be accumulating strain which could be released in a very large and violent rupture. On April 1 of this year, some of that strain was released offshore of Iquique. There was a Mw8.1 rupture in the northern portion of the seismic gap. But it involved slip over less than 20 percent of the region that seismologists believe to have accumulated strain since 1877.

"We have no idea why only a portion of the 1877 zone ruptured," said Lay. "But clearly, 80 percent of that zone is still unruptured. We don't have a good basis for assessment of how the rest will fail. It's the same for Cascadia. We don't know if it always goes all at once or sometimes in sequences of smaller events, with alternating pattern. It is prudent to prepare for the worst case of failure of the entire region in a single event, but it may not happen that way every time."

What is certain is that studying these recent big earthquakes has given geophysicists the best information ever about how they work and point to new ways to begin understanding what could be in Cascadia's future.

Explore further: Geologists warn of mega quake for north Chile

More information: A GLOBAL SURGE OF GREAT EARTHQUAKES FROM 2004-2014 AND IMPLICATIONS FOR CASCADIA
Abstract: gsa.confex.com/gsa/2014AM/webp … ram/Paper242140.html
Session No. 178. P4. Great Earthquakes, the Cascadia Subduction Zone, and Society I

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19 comments

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gkam
4 / 5 (4) Oct 21, 2014
Choose your poison, earthquakes, tornadoes, hurricanes, ice storms, or just bad places to live.
HannesAlfven
1 / 5 (11) Oct 22, 2014
The problem is that we like to imagine that the Earth is an isolated system in space. But, the data keeps on hinting that the electromagnetic activity we see in space can do things of importance to our planet's surface. The fact that we observe lightning to space at this point is a pretty big hint. Why does that even happen? The cosmic plasma models are rigged to assume that E-fields cannot be sustained in space. We might want to reconsider that, for critics of these models -- like George K Parks -- have suggested in papers that one need only go to the ionosphere to observe phenomena which these models cannot explain.
Vietvet
4.4 / 5 (7) Oct 22, 2014
@Hannes aka Velikvosky

It figures you would drag in the pseudoscience claptrap of EU when the article is about earthquakes.

barakn
5 / 5 (6) Oct 22, 2014
Here http://books.goog...;f=false we can see discussion of electric fields in the Parker spiral model of the solar wind. This from a book called "Basics of the Solar Wind." That's right - baby solar astronomers start learning about electric fields from the very beginning. And that makes HannesAlfven a liar.
redinguy2
1 / 5 (10) Oct 22, 2014
I am a scientific observer of the Bible and I watch the Bible very closely and how/if it coincides with science. I would suggest to all here to read Luke 21:1-10. And then look at the world. Some will scream: We have always had Great Earthquakes, Wars...diseases...famines...bad weather...Here is the alarm: We have never had all of these things at once. It is rather unique how Matthew 24: 1-36 and Luke 21: 1-10 are mirror views of what is going on today on a global scale not a resticted location. Any comments I welcome even critiques and opinions.
Doug Z
1 / 5 (3) Oct 23, 2014
For some science that may explain the global seismic situation, one may read the latest draft of the article 'Global View' which is available at: CelestialGeodynamics.org
Vietvet
3.8 / 5 (5) Oct 23, 2014
@Doug Z

Science and conjecture without peer review. And there is this-- "(solar eclipses produce maximum tides)"---- not true. If he is wrong about something so basic his whole hypnosis is highly suspect.

Doug Z
3.3 / 5 (3) Oct 23, 2014
Dear Vietvet:

You have taken a parenthetical totally out of context. The sentence was discussing the earth-tide generating effect of both lunar and solar eclipses--and of the two options, solar produce greater effect than lunar on the near side. Granted, there are NUMEROUS other location-specific factors involved in the generation of earth tides. And as they are out of phase with ocean tides, coastal locations are another matter, entirely.

Vietvet, I am sure that you mean well, but if this confused you, perhaps you shouldn't read on -- it is certainly not for everyone. That being said, thank you very much for your service to our country. I am old enough to have lost two classmates in the Vietnam War and I know that it was no party.
Vietvet
3.8 / 5 (4) Oct 23, 2014
@Doug Z

I'm not the least bit confused by what I read. His work needs peer review. Do you agree?
Doug Z
1 / 5 (3) Oct 23, 2014
I had peer review, but encountered two problems:

1. Because so many cooks, nuts, and even scientists of limited imagination have tainted the landscape of any work related to earthquake projections that although they would comment, they didn't want their names associated with the work. I, frankly, don't blame them. They are well-published, well-known, and certainly don't need to risk their professional statures.

2. This work involves knowledge of: astronomy, astrometry, celestial mechanics, geodesy, geophysics, spatial statistics, and seismology. Scientists usually are not comfortable in more than a few areas and so being of little budget, I did the best I could.
Doug Z
1.3 / 5 (3) Oct 23, 2014
3. The drafts posted are - working drafts. If a reader has a comment or suggestion, it can be constructively offered. A formal peer review can follow down the road.

4. Finally, with regard to the validity of the hypothesis: "The proof is in the pudding." The Los Angeles and San Francisco study applies ellipsoidal demand to the seismic history of both with apparently some success.
TheGhostofOtto1923
3 / 5 (2) Oct 23, 2014
And youll note, there seems to be a methane volcano brewing in americas heartland.
http://earthquake...kes/map/

-Most peculiar mama.
TheGhostofOtto1923
3.7 / 5 (3) Oct 23, 2014
The problem is that we like to imagine that the Earth is an isolated system in space. But, the data keeps on hinting that the electromagnetic activity we see in space can do things of importance to our planet's surface. The fact that we observe lightning to space at this point is a pretty big hint. Why does that even happen? The cosmic plasma models are rigged to assume that E-fields cannot be sustained in space. We might want to reconsider that, for critics of these models -- like George K Parks -- have suggested in papers that one need only go to the ionosphere to observe phenomena which these models cannot explain.
Hey arent you the guy who posted that vid of electric tornados carving canyons on mars? Your cred flew out the window on that one.
Doug Z
5 / 5 (1) Oct 23, 2014
@ TheGhost

Your 'methane volcano' is nothing new or perculiar:

http://www.scienc....summary
Bogey
5 / 5 (1) Oct 25, 2014
Lets not forget the humungus amount/weight of water/ice that we/it seems to be moving around at an increasingly rapid rate.
When it comes to push and shove.
Captain Stumpy
4 / 5 (4) Oct 25, 2014
We have always had Great Earthquakes, Wars...diseases...famines...bad weather...Here is the alarm: We have never had all of these things at once
@redinguy2
sorry, this is argument from ignorance
you have no proof of conjecture nor do you have references that support your conclusions
(the bible is a flawed system with known inconsistencies, therefore is a poor references for factual evidence within the realm of reality on historical fact)

This simple knowledge of "more wars" etc or "all at once" can also be attributed to instant worldwide communication as well as modern knowledge and instant sharing
the fact that you can KNOW about something as it happens in real time rather than read the news 3 months to 3 years later alters your perceptions about time as well as makes it difficult to correlate items to local events even without heavy research from the individual, which we know does not happen because people can be lazy and accepting of authority
Captain Stumpy
3.7 / 5 (3) Oct 25, 2014
@HannesAlfven
if you are going to conjecture about the beliefs or practices of modern astrophysicists then provide empirical evidence from a reputable source supporting your POV, otherwise it is trolling
Because so many cooks, nuts, and even scientists of limited imagination have tainted the landscape of any work related to
@Doug Z
arguing conspiracy is not proof of conjecture
and if you cannot PROVE conspiracy, then you are simply arguing from delusion
This work involves knowledge of... Scientists usually are not comfortable in more than a few areas
this is called argument from ignorance and appeal to authority based upon conspiracy and delusion
just because you assume something, does not make it legitimate or even real
A formal peer review can follow down the road
then it is NOT peer reviewed and therefore has the same standing as conjecture without evidence or self reference without reputabls science (IOW -pseudoscience)
Captain Stumpy
3.7 / 5 (3) Oct 25, 2014
Finally, with regard to the validity of the hypothesis: "The proof is in the pudding."
@Doug Z
poorly quoted and not referenced allusion to reality does not make this any more real than your faith or belief in its reality
the term is "the proof of the pudding is in the eating" which is NOT the same
even though repetition is making it more popular, the term is explained here: http://www.worldw...pro1.htm
it essentially means
don't assume that something is in order or believe what you are told, but judge the matter by testing it; it's much the same philosophy as in seeing is believing and actions speak louder than words
which is not what you appear to be saying

your conjecture is without the rigorous scientific testing required for a hypothesis to move forward and given the pudding comment, which says that your conjecture has no validity, this means that your argument is invalid and pseudoscience

Doug Z
1 / 5 (3) Oct 25, 2014
Dear Captain Stumpy:

Instead of spending time and energy flapping your lips about semantical nuance and theoretical mumbo jumbo, why don't you just read the first page of the draft Los Angeles study. If you think that it is invalid and pseudoscience - so be it. However, I will want your apology one year from today, if we actually do solve this seemingly intractable problem. Just select the latest draft:
http://www.celest...rancisco

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