SCEC Award Number 11094 View PDF
Proposal Category Collaborative Proposal (Data Gathering and Products)
Proposal Title Terrestrial Laser Scanning of the El Mayor-Cucapah Earthquake Rupture
Investigator(s)
Name Organization
Michael Oskin University of California, Davis Michael Taylor University of Kansas
Other Participants Eric Cowgill
SCEC Priorities A2, A9, B1 SCEC Groups Geology, Geodesy, FARM
Report Due Date 02/29/2012 Date Report Submitted N/A
Project Abstract
 We quantify one year of modification of fault scarps formed by the 2010 El Mayor-Cucapah (EMC) earthquake using terrestrial laser scanning (T-lidar). The first set of scans was acquired in late April, 2010 – 12-18 days after the earthquake. A second set of scans was acquired in April 2011, one year after the event. By comparing these scans we seek to measure three processes: (1) near-field post seismic deformation due to afterslip; (2) near-field subsidence from recovery of dilation induced by distributed deformation of fault-zone rocks; (3) erosion of the fault scarp and paleoseismic preservation of the rupture in fault-zone stratigraphy. We are also analyzing the first year of scans to precisely measure fault slip to understand sources of epistemic uncertainty that lead to scatter in fault slip measurements.
Intellectual Merit This study is among the first to scan and analyze fresh, meter-scale fault scarps. Occurring close to the U.S. border with Mexico, the EMC earthquake provided an opportunity to apply both airborne and terrestrial lidar to measure fault displacement and changes over time. By comparing these scans we seek to measure three processes: (1) near-field post seismic deformation due to afterslip; (2) near-field subsidence from recovery of dilation induced by distributed deformation of fault-zone rocks; (3) erosion of the fault scarp and paleoseismic preservation of the rupture in fault-zone stratigraphy. We are also analyzing the first year of scans to precisely measure fault slip to understand sources of epistemic uncertainty that lead to scatter in fault slip measurements.
Broader Impacts This research furthers collaboration between U.C. Davis, U. Kansas, and CICESE established after the 2010 EMC earthquake. Students from all of these institutions work together in the field, and UC Davis and U. Kansas students have also visited CICESE and collaborated directly with researchers and students there as a part of this project. For example, they produced a scan of the interior of a classroom at CICESE to demonstrate the hardware and provide a data set for use in a class project by CICESE students. CICESE researchers and students have also visited UC Davis to participate in training workshops on lidar. This project also represents an example of SCEC collaboration with UNAVCO, which provided the Reigl scanners at no charge to this project.
Exemplary Figure Figure 1 (lower 3 maps + profile example). By Austin Elliott. High resolution scans allow precise coregistration of 2011 scans with 2010 scans. Aside from vegetation that appears in the year 2 scans and not the year 1 scans, changes in elevation appear predominantly along the scarp, where gravity and wind have degraded the scarp crest and built talus cones upon the colluvial wedge at the base of the scarp.