Constraints on fault mechanics and seismic hazard from the integration of high- resolution topography and InSAR datasets

Scott Chelsea P, Ithaca NY

Investigators

Abstract

Dr. Chelsea P. Scott has been granted an NSF EAR Postdoctoral fellowship to carry out research and education activities at Arizona State University. The investigation will aim at improving constraints on fault slip rates estimated from both geologic and geodetic datasets. Accurate slip rates are critical to properly estimate future seismic activity in a region. Dr. Scott will use a novel approach of combining high-resolution topography and satellite radar datasets, bringing together complementary constraints on near- and far- field ground deformation. The improved understanding of fault mechanics from this study will result in better determination of fault slip rates in the geologic record and on quantified uncertainties of paleoseismic slip rates. In addition, the PI will lead workshops at the NSF-sponsored Open Topography facility, co-develop undergraduate courses at ASU, and promote computer-coding skills with high school women. This research will focus on using near- and far- field constraints on the magnitude and distribution of surface strain to infer the depth variability of fault slip. The fault slip models produced with InSAR data typically suggest little fault slip in the upper several kilometers of the crust, which is at odds with the topography data. The first goal of this project is to examine the distribution of fault slip inferred from the joint inversion of InSAR and differential topography data. The second goal of the project is to examine the implications for strain accumulation over many earthquake cycles. The study will improve constraints on the relative proportions of coseismic fault slip in the seismogenic crust. The improved understanding on fault mechanics will serve as input to further work in this project that will focus on quantifying the long-term variation in along-strike coseismic fault slip and the ratio between slip at the surface and at depth over many simulated earthquake cycles.