Featured Research

from universities, journals, and other organizations

3-D laser map shows earthquake before and after

Date:
February 9, 2012
Source:
University of California - Davis
Summary:
Geologists have a new tool to study how earthquakes change the landscape down to a few inches, and it's giving them insight into how earthquake faults behave.

An image of the 3-D visualization of an earthquake zone.
Credit: Image courtesy of University of California - Davis

Geologists have a new tool to study how earthquakes change the landscape down to a few inches, and it's giving them insight into how earthquake faults behave. In the Feb. 10 issue of the journal Science, a team of scientists from the U.S., Mexico and China reports the most comprehensive before-and-after picture yet of an earthquake zone, using data from the magnitude 7.2 event that struck near Mexicali, northern Mexico in April, 2010.

Related Articles


"We can learn so much about how earthquakes work by studying fresh fault ruptures," said Michael Oskin, geology professor at the University of California, Davis, and lead author on the paper.

The team, working with the National Center for Airborne Laser Mapping (NCALM), flew over the area with LiDAR (light detection and ranging), which bounces a stream of laser pulses off the ground. New airborne LiDAR equipment can measure surface features to within a few inches. The researchers were able to make a detailed scan over about 140 square miles in less than three days, Oskin said.

Oskin said that they knew the area had been mapped with LiDAR in 2006 by the Mexican government. When the earthquake occurred, Oskin and Ramon Arrowsmith at Arizona State University applied for and got funding from the National Science Foundation to carry out an immediate aerial survey to compare the results.

Co-authors John Fletcher and graduate student Orlando Teran from the Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) carried out a traditional ground survey of the fault rupture, which helped guide planning of the aerial LiDAR survey and the interpretation of the results.

From the ground, features like the five-foot escarpment created when part of a hillside abruptly moved up and sideways are readily visible. But the LiDAR survey further reveals warping of the ground surface adjacent to faults that previously could not easily be detected, Oskin said. For example, it revealed the folding above the Indiviso fault running beneath agricultural fields in the floodplain of the Colorado River.

"This would be very hard to see in the field," Oskin said.

Team members used the "virtual reality" facility at UC Davis' W.M. Keck Center for Active Visualization in Earth Sciences to handle and view the data from the survey. By comparing pre- and post-earthquake surveys, they could see exactly where the ground moved and by how much.

The survey revealed deformation around the system of small faults that caused the earthquake, and allowed measurements that provide clues to understanding how these multifault earthquakes occur.

The 2010 Mexicali earthquake did not occur on a major fault, like the San Andreas, but ran through a series of smaller faults in Earth's crust. These minor faults are common around major faults but are "underappreciated," Oskin said.

"This sort of earthquake happens out of the blue," he said.

The new LiDAR survey shows how seven of these small faults came together to cause a major earthquake, Oskin said.

Ken Hudnut, a geophysicist with the U.S. Geological Survey and co-author on the paper, made the first use of airborne LiDAR about 10 years ago to document surface faulting from the Hector Mine earthquake. But "pre-earthquake" data were lacking. Since then, NCALM has carried out LiDAR scans of the San Andreas system (the "B4 Project") and other active faults in the western U.S. (a component of the EarthScope Project), thereby setting a trap for future earthquakes, he said.

"In this case, fortunately, our CICESE colleagues had set such a trap, and this earthquake fell right into it and became the first ever to be imaged by 'before' and 'after' LiDAR. It is a thrill for me to be on the team that reached this important milestone," Hudnut said.

The post-event dataset collected by the team is publicly available through http://opentopography.org/.

Other authors on the paper are, at UC Davis: graduate student Austin Elliott and researcher Peter Gold; J. Ramon Arrowsmith, Arizona State University; Alejandro Hinojosa Corona and J. Javier Gonzalez Garcia, CICESE, Mexico; Eric Fielding, NASA Jet Propulsion Laboratory, Pasadena; and Jing Liu-Zeng, Chinese Academy of Sciences, Beijing. The work was supported by the National Science Foundation, the U.S. Geological Survey, Consejo Nacional de Ciencia y Tecnología (Mexico) and NASA.


Story Source:

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


Journal Reference:

  1. M. E. Oskin, J. R. Arrowsmith, A. H. Corona, A. J. Elliott, J. M. Fletcher, E. J. Fielding, P. O. Gold, J. J. G. Garcia, K. W. Hudnut, J. Liu-Zeng, O. J. Teran. Near-Field Deformation from the El Mayor-Cucapah Earthquake Revealed by Differential LIDAR. Science, 2012; 335 (6069): 702 DOI: 10.1126/science.1213778

Cite This Page:

University of California - Davis. "3-D laser map shows earthquake before and after." ScienceDaily. ScienceDaily, 9 February 2012. <www.sciencedaily.com/releases/2012/02/120209144007.htm>.
University of California - Davis. (2012, February 9). 3-D laser map shows earthquake before and after. ScienceDaily. Retrieved February 28, 2015 from www.sciencedaily.com/releases/2012/02/120209144007.htm
University of California - Davis. "3-D laser map shows earthquake before and after." ScienceDaily. www.sciencedaily.com/releases/2012/02/120209144007.htm (accessed February 28, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Saturday, February 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Whale-Watching Scientists Spot Baby Orca

Whale-Watching Scientists Spot Baby Orca

AP (Feb. 28, 2015) — Researchers following endangered killer whales spotted a baby orca off the coast of Washington state, the third birth documented this winter but still leaving the population dangerously low. (Feb. 28) Video provided by AP
Powered by NewsLook.com
Bridge Collapses Due to Flooding in Bolivia

Bridge Collapses Due to Flooding in Bolivia

Reuters - News Video Online (Feb. 28, 2015) — Heavy rain and flooding sweep through parts of Bolivia causing damage and leaves more than 2,000 people homeless. Sophia Soo reports. Video provided by Reuters
Powered by NewsLook.com
Death Toll from Afghan Avalanches Tops 200

Death Toll from Afghan Avalanches Tops 200

AFP (Feb. 27, 2015) — More than 200 people have been killed in a series of avalanches triggered by heavy snowfall in Afghanistan. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
France, Philippines Call for Agreement on Climate Change

France, Philippines Call for Agreement on Climate Change

Reuters - News Video Online (Feb. 27, 2015) — The presidents of France and the Philippines issue a joint appeal for a binding agreement on climate change. Katie Sargent 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:

More Coverage


3-D Map Study Shows Before-After of 2010 Mexico Quake

Feb. 13, 2012 — Geologists have a new tool to study how earthquakes change the landscape, and it's giving them insight into how earthquake faults behave. Scientists from the United States, Mexico and China ... read more

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