Featured Research

from universities, journals, and other organizations

Major offshore quake could surge inland to Seattle area

Date:
January 2, 2010
Source:
American Geophysical Union
Summary:
Large megathrust earthquakes occur on average every 550 years on the northern Cascadia subduction zone, where the Juan de Fuca tectonic plate subducts underneath the North American plate off the coast of Washington State. Scientists had thought that major earthquakes were likely to occur only offshore, but a new analysis shows that a giant earthquake could extend deeper along the subduction zone, and thus farther inland.

Large megathrust earthquakes occur on average every 550 years on the northern Cascadia subduction zone, where the Juan de Fuca tectonic plate subducts underneath the North American plate off the coast of Washington State. Scientists had thought that major earthquakes were likely to occur only offshore, but a new analysis by Chapman and Melbourne shows that a giant earthquake could extend deeper along the subduction zone, and thus farther inland.

The authors analyzed 15 small, nonearthquake periodic slip events known as episodic tremor and slip (ETS) detected between 1997 and 2008 to develop a model of seismogenic coupling between the two tectonic plates.

Their model accurately predicts the deformation of the overlying North American plate as measured by Global Positioning System stations and shows that seismic stress accumulation reaches to about 25 kilometers (15.5 miles) depth, or about 60 km (37.3 mi) inland, rather than stopping offshore at about 15 km (9.3 mi) depth, as had been thought. This indicates that the Seattle metropolitan areas could be subject to a magnitude 8.9 earthquake (from just the Washington State segment of Cascadia).

The authors conclude that results point to a need to reassess the Cascadia megathrust seismic hazard.

The research is published in Geophysical Research Letters. Authors include James S. Chapman and Timothy I. Melbourne: Department of Geological Sciences, Central Washington University, Ellensburg, Washington, USA


Story Source:

The above story is based on materials provided by American Geophysical Union. Note: Materials may be edited for content and length.


Journal Reference:

  1. Chapman et al. Future Cascadia megathrust rupture delineated by episodic tremor and slip. Geophysical Research Letters, 2009; 36 (22): L22301 DOI: 10.1029/2009GL040465

Cite This Page:

American Geophysical Union. "Major offshore quake could surge inland to Seattle area." ScienceDaily. ScienceDaily, 2 January 2010. <www.sciencedaily.com/releases/2009/12/091230183449.htm>.
American Geophysical Union. (2010, January 2). Major offshore quake could surge inland to Seattle area. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2009/12/091230183449.htm
American Geophysical Union. "Major offshore quake could surge inland to Seattle area." ScienceDaily. www.sciencedaily.com/releases/2009/12/091230183449.htm (accessed September 1, 2014).

Share This




More Earth & Climate News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Iceland Lowers Aviation Alert on Volcano

Iceland Lowers Aviation Alert on Volcano

AFP (Sep. 1, 2014) Iceland has lowered its aviation alert on its largest volcano after a fresh eruption on a nearby lava field prompted authorities to enforce a flight ban for several hours. Duration: 01:07 Video provided by AFP
Powered by NewsLook.com
Lightning Hurts 3 on NYC Beach

Lightning Hurts 3 on NYC Beach

AP (Sep. 1, 2014) A lightning strike injured three people on a New York City beach on Sunday. The storms also delayed flights and interrupted play at the US Open tennis tournament. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Thailand Totters Towards Waste Crisis

Thailand Totters Towards Waste Crisis

AFP (Sep. 1, 2014) Fears are mounting in Bangkok that poor planning and lax law enforcement are tipping Thailand towards a waste crisis. Duration: 01:21 Video provided by AFP
Powered by NewsLook.com
Melting Ice Shelves Drive Rapid Antarctic Sea Level Rise

Melting Ice Shelves Drive Rapid Antarctic Sea Level Rise

Newsy (Sep. 1, 2014) A study of almost 20 years' worth of satellite images shows Antarctic sea levels are on the rise as ice shelves continue to melt. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins