Featured Research

from universities, journals, and other organizations

San Andreas Fault Likely Much More Destructive Than Current Models Predict

Date:
August 21, 2007
Source:
University of Oxford
Summary:
High-speed ruptures travelling along straight fault lines could explain why some earthquakes are more destructive than others, according to an Oxford University scientist. Researchers suggest that ruptures in the Earth's surface moving at 6km per second could make future earthquakes along California's San Andreas fault much more destructive than current models predict.

A box canyon on the San Andreas fault: High speed ruptures travelling along the straight section of the fault could see Santa Barbara and Los Angeles worst hit in future earthquakes.
Credit: iStockphoto/Copyright William Royer

High-speed ruptures travelling along straight fault lines could explain why some earthquakes are more destructive than others, according to an Oxford University scientist. In this week’s Science, Professor Shamita Das suggests that ruptures in the Earth’s surface moving at 6km per second could make future earthquakes along California’s San Andreas fault much more destructive than current models predict.

Professor Das compared data from the 1906 California earthquake with data from a similar earthquake that occurred in 2001 in Kunlunshan, Tibet. The comparison suggests that, in both, the long straight portions of the fault enabled ruptures to travel twice as fast as the original ‘shear’ wave travelling through the rock. Such ‘super-shear’ waves were once thought to be impossible but could now explain why similar magnitudes of earthquake can cause much greater devastation in some areas than others.

‘Long straight faults are more likely to reach high rupture speeds,’ said Professor Das of the Department of Earth Sciences. ‘The fault starts from rest, then accelerates to the maximum permissible speed and continues at this speed until it reaches an obstacle such as a large ‘bend’. If the next earthquake in southern California follows the same pattern as the ones in California in 1857 and 1906, and in Tibet in 2001, a super-shear rupture travelling southward would strongly focus shock waves on Santa Barbara and Los Angeles.’

The 2001 Kunlunshan earthquake is of particular interest to scientists because it was so well preserved owing to its remote location and dry desert environment. Studies of the earthquake revealed telltale off-fault open cracks only at the portions where it was found to have a very high rupture speed. ‘These cracks confirm that the earthquake reached super-shear speeds on the long, straight section of the fault. This is the first earthquake where such direct evidence is available and it is exactly the kind of evidence that we do not have for the similar earthquake in California 1906, due to the heavy rains and rapid rebuilding that occurred there immediately afterwards.’

Professor Das believes that future research into rupture speeds could take scientists one step closer to predicting the potential impact of earthquakes in particular regions. She commented: ‘It appears that the 1857 and 1906 California earthquakes may have propagated faster than was previously thought. If this is the case then we need to apply the same analysis to other similar faults around the world. By developing a measure of the ‘straightness’ of faults and finding and recording evidence such as off-fault open cracks we hope to better understand these potentially devastating phenomena.’ The full article, entitled ‘The Need to Study Speed’, is published in Science on 17 August 2007.


Story Source:

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


Cite This Page:

University of Oxford. "San Andreas Fault Likely Much More Destructive Than Current Models Predict." ScienceDaily. ScienceDaily, 21 August 2007. <www.sciencedaily.com/releases/2007/08/070819085711.htm>.
University of Oxford. (2007, August 21). San Andreas Fault Likely Much More Destructive Than Current Models Predict. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2007/08/070819085711.htm
University of Oxford. "San Andreas Fault Likely Much More Destructive Than Current Models Predict." ScienceDaily. www.sciencedaily.com/releases/2007/08/070819085711.htm (accessed October 21, 2014).

Share This



More Earth & Climate News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
White Rhino's Death In Kenya Means Just 6 Are Left

White Rhino's Death In Kenya Means Just 6 Are Left

Newsy (Oct. 20, 2014) Suni, a rare northern white rhino at Ol Pejeta Conservancy, died Friday. This, as many media have pointed out, leaves people fearing extinction. Video provided by Newsy
Powered by NewsLook.com
New Organic Fertilizer Helps Reforestation of Monarch Butterflies’ Winter Retreat

New Organic Fertilizer Helps Reforestation of Monarch Butterflies’ Winter Retreat

Reuters - Innovations Video Online (Oct. 20, 2014) Using an organic fertiliser, a conservationist from the National Autonomous University of Mexico (UNAM), leads an award-winning project to reforest the sanctuary of monarch butterflies. Sharon Reich reports. Video provided by Reuters
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