Abstract:
The 2019 Mw 7.1 Ridgecrest earthquake, preceded by a Mw 6.4 events within less than 48 hours, was one of the largest events happened close to the Greater Los Angeles area. In this talk, I will give an overview of the earthquake cycle, recorded seismic and geodetic data including InSAR (Interferometric Synthetic Aperture Radar), and the associated stress and strain changes within the brittle crust. The presentation will focus on more than 2 years of postseismic deformations of the Ridgecrest earthquake sequence, where the obtained spatiotemporal variations of the stress field, the surface deformations and the afterslip models will be discussed in detail. The stress field is estimated inverting more than 4,500 fault plane solutions within the postseismic time period. The surface deformations are estimated obtaining ARIA (Caltech-JPL Advanced Rapid Imaging and Analysis) products, which has been systematically processing InSAR data from the Copernicus Sentinel-1 satellites with two tracks of C-band SAR data covering the study area, and recording more than 30 interferograms from each of the ascending track 64 and the descending track 71 every 6 and 12 days. The afterslip model is obtained combining the InSAR together with the GNSS (Global Navigation Satellite System) data, which are obtained from GeoGateway, a data product and analysis tool developed by NASA consisting of geodetic imaging products. Integrating the obtained analysis, we investigate locations with higher variations in the strain-rate and stress field to detect zones that are potential for higher stress accumulations and seismic hazard.
About the Speaker:
Niloufar Abolfathian is currently a Postdoctoral Scholar at Jet Propulsion Laboratory working under supervision of Dr. Eric Fielding. She is interested in integrating theoretical, observational, and computational methods to come up with a better understanding of earthquake cycles, fault mechanics, and further earthquake likelihood and seismic hazard analysis. She studies the state of the stress and strain in fault zone area, and the associated earthquake fault processes and crustal deformations. Niloufar received her Ph.D. at the University of Southern California in Geophysics in 2020. She has a M.Sc. in Earth Sciences from the ETH Zurich and B.Sc. in Chemical Engineering from the Sharif University of Technology. She was awarded Best Student Presentation award at the Seismological Society of America.
