Featured Research

from universities, journals, and other organizations

West Coast Earthquakes Ongoing, Scientists Discover

Date:
March 29, 2002
Source:
National Science Foundation
Summary:
The most recent evidence indicates there is an earthquake going on right now on the West Coast, yet no one feels it. The temblor, a so-called slow earthquake, has been ongoing since about Feb. 7, according to geologist Meghan Miller of Central Washington University in Ellensburg. She was among the first scientists to use GPS (global positioning system) technology to study earthquakes.

The most recent evidence indicates there is an earthquake going on right now on the West Coast, yet no one feels it. The temblor, a so-called slow earthquake, has been ongoing since about Feb. 7, according to geologist Meghan Miller of Central Washington University in Ellensburg. She was among the first scientists to use GPS (global positioning system) technology to study earthquakes.

An article written by Miller and colleagues, "Periodic Slow Earthquakes from the Cascadia Subduction Zone," is published in this week’s (March 29) edition of the journal Science. The cited research was funded by the National Science Foundation (NSF).

"The only way we can observe these slow earthquakes is through this instrumentation," Miller says. "Until we had GPS geodesy, we regarded earthquake deformation in two main ways: long-term, steady state faculty motions, and the elastic strain where faults are stuck and let go during earthquakes. If it turns out that a major mechanism for releasing this elastic strain is through slow earthquakes that don't generate seismic shaking, then they become very important to understand."

Adds Jim Whitcomb of NSF’s division of earth sciences, which funded the research, “Understanding these ‘silent earthquakes’ that we have been missing all these years will have a profound effect on our ability to predict hazards from volcanoes and earthquakes.”

These quakes occur in an area of the plate boundary fault known as the transition zone, below where the tectonic plates are stuck and release strain during earthquakes, and above the portion where the fault slips continuously.

"These areas seem to be 'meta-stable' - stuck enough that they don't move until a critical threshold is reached and they slip, but don't rupture catastrophically," Miller states. "They can take place over the course of hours, days, weeks - maybe years."

These slow earthquakes seem to initiate in Puget Sound near Whidbey Island and spread out from there, she adds. Miller and her colleagues have reviewed a decade's worth of GPS data, determining that eight slow earthquakes took place in the same general vicinity over that period, all about 14 months apart.

“It means that we could recognize this, speculate when an event may happen and then test that hypothesis,” Miller points out. Even though Miller calls the regularity and the frequency of the slow earthquakes "stunning," 10 years is so small in geological time that she is not willing to speculate that they are the norm.

"Most times when we've recognized periodicity in solid earth behavior, we've been wrong," she says. "And we can still be wrong here. But, certainly over the past 10 years it's been highly periodic. Whether that holds for the entire inter-seismic cycle between great earthquakes is in question."

Miller adds it's not yet known whether slow earthquakes can actually herald - or trigger - larger ones.


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "West Coast Earthquakes Ongoing, Scientists Discover." ScienceDaily. ScienceDaily, 29 March 2002. <www.sciencedaily.com/releases/2002/03/020329071528.htm>.
National Science Foundation. (2002, March 29). West Coast Earthquakes Ongoing, Scientists Discover. ScienceDaily. Retrieved August 31, 2014 from www.sciencedaily.com/releases/2002/03/020329071528.htm
National Science Foundation. "West Coast Earthquakes Ongoing, Scientists Discover." ScienceDaily. www.sciencedaily.com/releases/2002/03/020329071528.htm (accessed August 31, 2014).

Share This




More Earth & Climate News

Sunday, August 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Volcano Erupts on Papua New Guinea

Raw: Volcano Erupts on Papua New Guinea

AP (Aug. 29, 2014) Several communities were evacuated and some international flights were diverted on Friday after one of the most active volcanos in the region erupts. (Aug. 29) Video provided by AP
Powered by NewsLook.com
Raw: Small Volcanic Eruption in Iceland

Raw: Small Volcanic Eruption in Iceland

AP (Aug. 29, 2014) Icelandic authorities briefly raised the aviation warning code to red on Friday during a small eruption at the Holuhraun lava field in the Bardabunga volcano system. (Aug. 29) Video provided by AP
Powered by NewsLook.com
As Drought Continues LA "water Police" Fight Waste

As Drought Continues LA "water Police" Fight Waste

AFP (Aug. 29, 2014) In the midst of a historic drought, Los Angeles is increasing efforts to go after people who waste water. Five water conservation "cops" drive around the city every day educating homeowners about the drought. Duration: 02:17 Video provided by AFP
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
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