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."

Related Articles


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 December 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 December 17, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Wednesday, December 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
Powered by NewsLook.com
Indictments in West Virginia Chemical Spill Case

Indictments in West Virginia Chemical Spill Case

AP (Dec. 17, 2014) A grand jury indicted four former executives of Freedom Industries, the company at the center of the Jan. 9, 2014 chemical spill in Charleston, West Virginia. The spill contaminated the Elk River and the water supply of 300,000 people. (Dec. 17) Video provided by AP
Powered by NewsLook.com
Uphill Battle to Tackle Indonesian Shark Fishing

Uphill Battle to Tackle Indonesian Shark Fishing

AFP (Dec. 17, 2014) Sharks are hauled ashore every day at a busy market on the central Indonesian island of Lombok, the hub of a booming trade that provides a livelihood for local fishermen but is increasingly alarming environmentalists. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
France's Sauternes Wine Threatened by New Train Line

France's Sauternes Wine Threatened by New Train Line

AFP (Dec. 16, 2014) Winemakers in southwestern France's Bordeaux are concerned about a proposed high speed train line that could affect the microclimate required for the region's sweet wine. Duration: 01:06 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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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