Featured Research

from universities, journals, and other organizations

Unusual fault pattern surfaces in earthquake study

Date:
August 12, 2011
Source:
NASA/Jet Propulsion Laboratory
Summary:
Like scars that remain on the skin long after a wound has healed, earthquake fault lines can be traced on Earth's surface long after their initial rupture. Typically, this line of intersection is more complicated at the surface than at depth. But a new study of the April 4, 2010, El Mayor-Cucapah earthquake in Baja California, Mexico, reveals a reversal of this trend. Superficially, the fault involved in the magnitude 7.2 earthquake appeared to be straight, but at depth, it's warped and complicated.

Horizontal motion measured from radar images reveals the faults that moved in the magnitude 7.2 earthquake in Baja California, Mexico.
Credit: JAXA/METI/NASA/JPL-Caltech

Like scars that remain on the skin long after a wound has healed, earthquake fault lines can be traced on Earth's surface long after their initial rupture. Typically, this line of intersection is more complicated at the surface than at depth. But a new study of the April 4, 2010, El Mayor-Cucapah earthquake in Baja California, Mexico, reveals a reversal of this trend. Superficially, the fault involved in the magnitude 7.2 earthquake appeared to be straight, but at depth, it's warped and complicated.

The study, which was led by researchers at the California Institute of Technology with NASA Jet Propulsion Laboratory geophysicist Eric Fielding serving as a coauthor, is available online in the journal Nature Geoscience.

In a standard model, transform plate boundary structures -- where two plates slide past one another -- tend to be vertically oriented, which allows for lateral side-by-side shear fault motion. However, as the study found, the 75 mile (120 kilometer) long El Mayor-Cucapah rupture involved angled, non-vertical faults and the event began on a connecting extension fault between the two segments.

The new analysis indicates the responsible fault is more segmented deep down than its straight surface trace suggests. This means the evolution and extent of this earthquake's rupture could not have been accurately anticipated from the surface geology alone, says the study's lead author Shengji Wei. Anticipating the characteristics of earthquakes that would likely happen on young fault systems (like the event in the study) is a challenge, since the geologic structures involved in the new fault systems are not clear enough.

Jean-Philippe Avouac, director of Caltech's Tectonics Observatory and principal investigator on the study, says the data can be used to illustrate the process by which the plate boundary -- which separates the Pacific Plate from North America -- evolves and starts connecting the Gulf of California to the Elsinore fault in Southern California.


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. The original article was written by Katie Neith. Note: Materials may be edited for content and length.


Journal Reference:

  1. Shengji Wei, Eric Fielding, Sebastien Leprince, Anthony Sladen, Jean-Philippe Avouac, Don Helmberger, Egill Hauksson, Risheng Chu, Mark Simons, Kenneth Hudnut, Thomas Herring, Richard Briggs. Superficial simplicity of the 2010 El Mayor–Cucapah earthquake of Baja California in Mexico. Nature Geoscience, 2011; DOI: 10.1038/ngeo1213

Cite This Page:

NASA/Jet Propulsion Laboratory. "Unusual fault pattern surfaces in earthquake study." ScienceDaily. ScienceDaily, 12 August 2011. <www.sciencedaily.com/releases/2011/08/110812094507.htm>.
NASA/Jet Propulsion Laboratory. (2011, August 12). Unusual fault pattern surfaces in earthquake study. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2011/08/110812094507.htm
NASA/Jet Propulsion Laboratory. "Unusual fault pattern surfaces in earthquake study." ScienceDaily. www.sciencedaily.com/releases/2011/08/110812094507.htm (accessed April 25, 2014).

Share This



More Earth & Climate News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Fungus Killing Bats, Spreading in US

Deadly Fungus Killing Bats, Spreading in US

AP (Apr. 24, 2014) A disease that has killed more than six million cave-dwelling bats in the United States is on the move and wildlife biologists are worried. White Nose Syndrome, discovered in New York in 2006, has now spread to 25 states. (April 24) Video provided by AP
Powered by NewsLook.com
New Pictures of Ship That Sank in 1888

New Pictures of Ship That Sank in 1888

AP (Apr. 24, 2014) Federal researchers have released new images of the City of Chester, a steamship that sank in San Francisco Bay in 1888. Researchers recently found the shipwreck while mapping shipping routes. (April 24) Video provided by AP
Powered by NewsLook.com
Risk of Asteroid Hitting Earth Higher Than Thought, Study Shows

Risk of Asteroid Hitting Earth Higher Than Thought, Study Shows

Reuters - US Online Video (Apr. 23, 2014) A group of space explorers say the chance of a city-obliterating asteroid striking Earth is higher than scientists previously believed. Deborah Gembara reports. Video provided by Reuters
Powered by NewsLook.com
UN Joint Mission Starts Removing Landmines in Cyprus

UN Joint Mission Starts Removing Landmines in Cyprus

AFP (Apr. 23, 2014) The UN mission in Cyprus (UNFICYP) led a mine clearance demonstration on Wednesday in the UN-controlled buffer zone where demining operations are being conducted near the Cypriot village of Mammari. Duration: 01:00 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:

More Coverage


El Mayor-Cucapah Earthquake Was Simple on Surface, Complicated at Depth, New Data Show

Aug. 11, 2011 Like scars that remain on the skin long after a wound has healed, earthquake fault lines can be traced on Earth's surface long after their initial rupture. Typically, this line of intersection ... read more
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