Featured Research

from universities, journals, and other organizations

Nevada Seismology Researchers Develop Model That Estimates Impact Of Large Earthquake In Los Angeles

Date:
December 28, 2004
Source:
University Of Nevada, Reno
Summary:
Stiffer building codes in the Los Angeles basin may come in the near future as a result of a new study completed by University of Nevada, Reno seismologists of an anticipated large thrust-fault earthquake.

Seismologists Rasool Anooshehpoor and Jim Brune in front of their large foam-rubber model of a thrust-fault. Photo by Jean Dixon.

Stiffer building codes in the Los Angeles basin may come in the near future as a result of a new study completed by University of Nevada, Reno seismologists of an anticipated large thrust-fault earthquake.

"Our study in California's Kern County is a good indicator of what could happen in Los Angeles because the geology of the areas is so similar," said James Brune, seismology pioneer and University Foundation Professor. The conditions, he said, would indicate "high motion" in Los Angeles.

His team's study in Kern County is a scenario for a large earthquake in the Los Angeles basin because the downtown portion of the city is on the hanging-wall of the Puente Hills thrust fault. The study involved looking at what levels of peak ground acceleration were necessary to topple a balanced rock or a rigid transformer. Their conclusions reinforce that the hanging-wall side of large thrust-fault earthquakes experience more extreme motion and, therefore, more damage than the footwall side.

A thrust-fault earthquake occurs when the land on one side of a fault (the "hanging-wall") gets driven up and over land on the other side (the "foot-wall"), he explained. This is different from a normal fault earthquake where land on one side of the fault gets pulled down and away from the land on the other side.

Brune and his team of University professors, Abdolrasool Anooshehpoor, Baoping Shi and Yuehua Zeng, have further proved that the geometry of thrust faults can dictate the range of an earthquake's damage in their study, "Precarious Rock and Overturned Transformer Evidence for Ground Shaking in the Ms=7.7 Kern County Earthquake: an Analog for Disastrous Shaking from a Major Thrust Fault in the Los Angeles Basin." This article will soon be published in the Bulletin of the Seismological Society of America.

"This is the first extensive data set from a major thrust-fault earthquake in the United States," said Anooshehpoor. "The only other data on these faults come from a 1999 quake in Taiwan."

Brune and his team have supplemented data from Taiwan with recent research which shows that precariously balanced rocks and overturned transformers in the vicinity of the White Wolf fault, south of Bakersfield, Calif., provide an understanding of thrust-fault earthquake ground motion that has been otherwise unavailable. The team also complemented their rock research by studying large foam-rubber models of faults and computer simulations of quakes.

According to Brune, precariously balanced rocks evolve naturally unless shaken down by earthquakes. As a result, these rocks are effective earthquake seismoscopes. Zones of precarious rocks are direct evidence that no strong ground accelerations have occurred for thousands of years, and as a result they potentially provide important information about seismic risk.

"The brilliance of this balanced-rock research is that it gives us a way to test ground-motion probability which can dictate building codes," said John Anderson, University professor of geophysics and director of the Nevada Seismological Laboratory.

The next United States Geological Survey hazard methodologies which are based on ground-motion probability are slated for release in 2007. These methodologies are used by engineers to frame building codes. Many anticipate that Brune's study will be used to update these codes because the research provides new quantitative constraints on seismic hazard.

###

The University of Nevada, Reno has one of the world's most respected seismology research and earthquake engineering teams. Its Nevada Seismological Laboratory has overall responsibility for instrumental studies of earthquakes throughout the state. This laboratory also serves as a repository of information and a resource for the public on earthquake activity, risks and safety measures in Nevada and adjoining states.

The University's Nevada Seismological Laboratory operates more than 350 stations throughout the Nevada and eastern California region. Its modern digital seismic instruments can sense the tiniest earthquakes even at depths of 20 miles below the surface.

This network, which is part of the Advanced National Seismic System, is supported by the U. S. Geological Survey as part of the National Earthquake Hazard Reduction Program, the U. S. Department of Energy and by the State of Nevada.


Story Source:

The above story is based on materials provided by University Of Nevada, Reno. Note: Materials may be edited for content and length.


Cite This Page:

University Of Nevada, Reno. "Nevada Seismology Researchers Develop Model That Estimates Impact Of Large Earthquake In Los Angeles." ScienceDaily. ScienceDaily, 28 December 2004. <www.sciencedaily.com/releases/2004/12/041219145741.htm>.
University Of Nevada, Reno. (2004, December 28). Nevada Seismology Researchers Develop Model That Estimates Impact Of Large Earthquake In Los Angeles. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2004/12/041219145741.htm
University Of Nevada, Reno. "Nevada Seismology Researchers Develop Model That Estimates Impact Of Large Earthquake In Los Angeles." ScienceDaily. www.sciencedaily.com/releases/2004/12/041219145741.htm (accessed October 2, 2014).

Share This



More Earth & Climate News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dolphins and Turtles Under Threat in Pakistan

Dolphins and Turtles Under Threat in Pakistan

AFP (Oct. 2, 2014) — The turtles and Dolphins of Pakistan's Indus river - both protected by law - are in a fight for their survival as man's activities threatens their futures. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Volcano Rescue Video Released

Raw: Japan Volcano Rescue Video Released

AP (Oct. 2, 2014) — The Tokyo Fire Department released video of rescue efforts following Saturday's eruption of Mount Ontake in central Japan. It shows firefighters and military troops carrying injured people as plumes of smoke pour from the volcano behind them. (Oct. 2) Video provided by AP
Powered by NewsLook.com
Raw: 12 More Bodies Found on Japan Volcano

Raw: 12 More Bodies Found on Japan Volcano

AP (Oct. 1, 2014) — A dozen more bodies were found Wednesday as Japanese rescuers resumed efforts to find survivors and retrieve bodies of those trapped by Mount Ontake's eruption. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. 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:

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