New study finds Seattle in danger from a massive earthquake
Puget Sound under threat of a megathrust earthquake which occurs only once every 500 years.
Photo: Papalars/Flickr
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New study finds Seattle in danger from a massive earthquakePuget Sound under threat of a megathrust earthquake which occurs only once every 500 years.By Katherine ButlerThu, Dec 17 2009 at 3:04 PM EST
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Photo: Papalars/Flickr A recent study presented at the American Geophysical Union's annual meeting shows Seattle may suffer from a future megathrust earthquake. Previously, Seattle was thought to be relatively safe. But University of Washington earth scientist Kenneth Creager reveals otherwise. According to Creager, new evidence “continues to paint the picture of the possibility that a megathrust earthquake can occur closer to the Puget Sound region than was thought just a few years ago."
Scientists report that megathrust quakes occur roughly every 500 years along the Cascadia subduction zone. This zone runs from Northern California to Vancouver Island in British Columbia, just where the Juan de Fuca tectonic plate dips beneath the North American plate.
According to scientists, this is a locked area that can produce a megathrust earthquake, causing widespread heavy damage. Massive magnitude 9 earthquakes occur about every 500 years. An earthquake of this magnitude would be comparable to the 2004 Indian Ocean earthquake which caused a devastating tsunami.
How have scientists come to this conclusion? Rumblings have been recently detected in the Cascadia zone. According to Creager, "There appear to be tremor swarms that repeat, both in terms of their duration and in where they are." These rumblings last anywhere from one to 70 hours, and they occur in semi-regular patterns between the "tremor and slip" events that scientists were already monitoring.
Apparently, the two tectonic plates are locked together. Consequently, stress builds at their interface as they collide with each other at a rate of about 4 centimeters, or 1.6 inches a year. These tremor and slip events occur at the interface of the plates as they gradually descend beneath the surface, at depths of about 19 to 28 miles.
By studying these small tremors, scientists are getting a better idea of just how a megathrust earthquake would affect Seattle and its outlying areas. Hopes remain that the study will enable engineers to revise building codes in preparation. Buildings would be able to withstand a huge quake, especially if the source is substantially closer to the city than it was previously expected to be.
But don’t stock up on batteries quiet just yet. The last megathrust earthquake occurred in 1700, which makes the Pacific Northwest due another one sometime around 2200.
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Related Topics: Environmental Research, Research & Innovation
Comments
Daniel Espejel
03/23/2011 22:30 PM
Almost a week and a half japan had one of the biggest earth quake in history. Haiti had one really similar to japan as well as Chile. The ring of fire has started once again, as like the time of the dinosaurs. If its are time, we kind of deserve it cause really look at what we have done to this place. But who ever lives right next to Seattle like me, prepare your safety equipment so when this happens your prepared.
David
02/26/2010 14:44 PM
I'm a scientist who studies convergent plate margins, my research involves fold and thrust belts in taiwan. The evidence for plate tectonic theory is absolutely overwhelming, and geodetic data is useless unless a reference frame is used. The person below who suggested that vancouver is "wobbling" or rotating. It sure could be, with respect to what fixed point though? Most plates and microplates have a rotational component when the datum is altered. Gps shows distinct plate motions,.... More
bjspa764
12/18/2009 01:19 AM
Plate Tectonics is WRONG?! There is too much evidence to just ignore it. And there will be megathrust earthquakes in the future. It has happened MANY times in the past, as an example 1700. This could actually happen at any time! It will release when it needs to. Also, if there isn't plate tectonics, then what are the earthquakes that kill thousands of people and animals come from. I ask you that Originofquake!
Originofquake
12/17/2009 19:35 PM
Kids do not worroy. Sleep tight and tell your teacher that you have proof that the socalled megathrust is false and is not a correct assumption. Sorry for misspelling the word tomOrrow. My message about these TV shows cause anxiety in young people. You need to know a little about geology- like the Juan De fuca ridge heading toward the coast near Vancover is a foot print of a massive ice cap that covered the Pacific Ocean. This ice cap 16 million years ago pushed the mountains inland like a.... More
Originofquake
12/17/2009 17:56 PM
Men of good will not have an agenda to provide scary nonsence for a TV show. These scientist must stop the crazy assumptions and admit they do'nt know anything.Plate Tectonics is wrong. The GPS shows Vancover Island is moving in a circle. What a joke. The 14 month circle is the 14 month circle called the Chandler Wobble. Every 14 months the spin of the earth wobbles and projected against the sky would make a circle every 14 months about the size of the infield of a baseball field. Add your commentSign in with one of these accounts or just add your comment below. |
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