Rapid Response Research (RAPID) Proposal for the April 4, 2010 Mw 7.2 El Mayor-Cucapah Earthquake, Northern Baja California, Mexico

University Of Arizona, Tucson AZ

Investigators

Abstract

This project is focusing on ongoing crustal motions in northern Baja Califorrnia, Mexico, associated with the 4 April 2010 Mw7.2 Sierra El Mayor-Cucapah earthquake. The project is utilizing new continuous GPS (CGPS) stations located in northern Baja California to measure transient crustal motions following the earthquake. The new 6-station network complements and enhances the EarthScope PBO network, providing needed data for studies of lithospheric rheology and for monitoring earthquake hazards in northern Baja and southern California. A model for pre-earthquake crustal velocities at the six new CGPS stations is being developed for direct comparison with post-earthquake motions, using existing campaign GPS measurements collected over the past two decades. New data from the continuous GPS stations and precise estimates for pre-earthquake crustal velocities are forming the basis for an evaluation of perturbations to the velocity field caused by the earthquake, including determination of realistic uncertainties in the earthquake-related velocity change estimates. These geodetic results are enabling a robust study of crust and mantle rheology and the role that postseismic processes play in the evolution of crustal stresses in southern California and northern Mexico, with implications for earthquake hazards assessment. This project is helping to support one PhD student at The University of Arizona, and is strengthening scientific ties with our Mexican collaborators at CICESE, who are our natural partners in earthquake science and hazard research associated with the southern San Andreas fault system.