Featured Research

from universities, journals, and other organizations

Homing in on a potential pre-quake signal

Date:
August 2, 2012
Source:
Seismological Society of America
Summary:
In a new analysis of the 2004 magnitude 6.0 Parkfield earthquake in California, David Schaff suggests some limits on how changes measured by ambient seismic noise could be used as a pre-earthquake signal.

Changes in seismic velocity--changes in the speeds at which seismic waves move through Earth's crust--have been identified during and after many earthquakes. But do these changes also happen before an earthquake, and could they be measured as a way to predict a quake on the way? The search for a clear and measurable pre-quake signal has been called "the holy grail of seismology."

In a new analysis of the 2004 magnitude 6.0 Parkfield earthquake in California, David Schaff suggests some limits on how changes measured by ambient seismic noise could be used as a pre-earthquake signal. Ambient seismic noise refers to the "background hum" of Earth--the surface waves found all over the planet's crust that are caused mostly by wind and ocean waves. Changes in seismic velocity can be measured using seismic noise observations, which are often recorded continuously at seismic stations and therefore can provide a detailed record of a pre-earthquake time period.

Using a complete set of noise data from the Parkfield earthquake, Schaff was able to search for a pre-seismic signal to the quake. He was unable to detect any pre-seismic velocity change for Parkfield using the noise data, but he notes that any pre-seismic signal may have been too small, too short in duration, or in a different area outside of the network of seismic monitors. The analysis did allow Schaff to place an upper limit on how large such a signal might be, depending on how many days it might be observed before the main quake.

The paper, "Placing an Upper Bound on Preseismic Velocity Changes Measured by Ambient Noise Monitoring for the 2004 Mw 6.0 Parkfield Earthquake (California)" will appear in the August issue of the Bulletin of the Seismological Society of America.


Story Source:

The above story is based on materials provided by Seismological Society of America. Note: Materials may be edited for content and length.


Cite This Page:

Seismological Society of America. "Homing in on a potential pre-quake signal." ScienceDaily. ScienceDaily, 2 August 2012. <www.sciencedaily.com/releases/2012/08/120802122514.htm>.
Seismological Society of America. (2012, August 2). Homing in on a potential pre-quake signal. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2012/08/120802122514.htm
Seismological Society of America. "Homing in on a potential pre-quake signal." ScienceDaily. www.sciencedaily.com/releases/2012/08/120802122514.htm (accessed April 17, 2014).

Share This



More Earth & Climate News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
Powered by NewsLook.com
The Walking, Talking Oil-Drigging Rig

The Walking, Talking Oil-Drigging Rig

Reuters - Business Video Online (Apr. 15, 2014) Pennsylvania-based Schramm is incorporating modern technology in its next generation oil-drigging rigs, making them smaller, safer and smarter. Ernest Scheyder reports. Video provided by Reuters
Powered by NewsLook.com
In Washington, a Push to Sterilize Stray Cats

In Washington, a Push to Sterilize Stray Cats

AFP (Apr. 14, 2014) To curb the growing numbers of feral cats in the US capital, the Washington Humane Society is encouraging residents to set traps and bring the animals to a sterilization clinic, after which they are released.. Duration: 02:29 Video provided by AFP
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