Vertical Deformation Dependency on Spatially Variable Elastic Plate Thickness: Insights from the 2019 Ridgecrest Earthquake Sequence

Lauren A. Ward, Bridget R. Smith-Konter, Xiaohua Xu, & David T. Sandwell

Published August 15, 2020, SCEC Contribution #10740, 2020 SCEC Annual Meeting Poster #117

Benefiting from both spatially and temporally dense instrumentation and remotely sensed observations, deformation from the 2019 Ridgecrest earthquake sequence is poised to become one of the best observed co- and postseismic processes to date. These new observations add to an already rich record of crustal motions provided by three other >Mw7 earthquakes in southern California over the last 3 decades. In particular, vertical time series data from Ridgecrest are beginning to reveal transient postseismic motions that are strongly influenced by lithosphere rheology. Here we focus on the vertical earthquake cycle deformation signal and its sensitivity to spatial variations in lithosphere rheology by leveraging new crustal deformation data acquired from the 2019 Ridgecrest earthquake sequence. We utilize a 4-D semi-analytic viscoelastic deformation model that simulates both the elastic and time-dependent viscoelastic response of body force dislocations embedded in an elastic plate overlying a viscoelastic half-space. The model is additionally able to simulate lateral variations in crustal rheology parameters, which we define using the SCEC CTM. Vertical geodetic velocities from the SCEC CGM and GNSS are used to perform a joint inversion for seismic moment rate to investigate the significance of spatially variable rheology on earthquake cycle vertical deformation.

Key Words
Vertical Deformation, Elastic Plate Thickness, Earthquake Cycle Model

Citation
Ward, L. A., Smith-Konter, B. R., Xu, X., & Sandwell, D. T. (2020, 08). Vertical Deformation Dependency on Spatially Variable Elastic Plate Thickness: Insights from the 2019 Ridgecrest Earthquake Sequence. Poster Presentation at 2020 SCEC Annual Meeting.

Related Projects & Working Groups
Stress and Deformation Over Time (SDOT)