Laser tool maps quake-related devastation in 3D

 A new laser guided tool is helping geologists map in 3D exactly how earthquakes wreck landscapes, down to a few square inches of the devasted zone.

Scientists from the US, Mexico and China reported the most comprehensive before-and-after picture yet of an earthquake zone using data from the magnitude 7.2 event that struck near Mexicali, Mexico, in April 2010.

New airborne LiDAR (light detection and ranging) equipment helped researchers make a detailed scan over about 140 square miles in less than three days, said Michael Oskin, geologist at the University of California, Davis, who led the study.

"We can learn so much about how earthquakes work by studying fresh fault ruptures," Oskin was quoted as saying by the journal Science.

The team, working with the National Centre for Airborne Laser Mapping (NCALM), flew over the area with LiDAR, which bounces a stream of laser pulses off the ground. Oskin said that they knew the area had been mapped with LiDAR in 2006 by the Mexican government, said a univeristy statement.

When the earthquake occurred, Oskin and Ramon Arrowsmith of Arizona State University received rapid-response funding from the National Science Foundation (NSF) to carry out an immediate aerial survey to compare the results.

Co-authors John Fletcher and Orlando Teran from Mexico's Ensenada Center for Scientific
Research and Higher Education (CICESE), carried out a traditional ground survey of the fault rupture, which helped guide planning of the aerial LiDAR survey and interpretation of the results.

"This study is an excellent demonstration of an emerging tool for Earth science," said Greg Anderson, NSF program director for EarthScope, which funded the research.
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