Poster #105, Tectonic Geodesy

Rheological implications of post-seismic deformation following the 2019 Ridgecrest Earthquakes

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Poster Presentation

2020 SCEC Annual Meeting, Poster #105, SCEC Contribution #10705
Post-seismic deformation following large earthquakes offers insights into the rheology of the lithosphere and upper asthenosphere. Unprecedented geodetic coverage of the 2019 Ridgecrest earthquakes provides an opportunity to test whether rheological models developed for the Mojave, from the Landers, Hector Mine and El Major Cucapah earthquakes, are applicable north of the Garlock fault, and to place bounds on the effects of local rheological heterogeneties associated with the Coso volcanic field. We use variational Bayesian independent component analysis to isolate postseismic deformation in GPS time series around the earthquakes. We use forward models driven by coseismic stress changes to assess the respective contributions of poroelastic rebound, afterslip and viscoelastic deformation to the first year of GPS-recorded surface displacements. We use these models to identify features of the GPS- and InSAR-derived surface deformation which are, or may become, diagnostic of different post-seismic mechanisms and rheological heterogeneities.