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InSAR Community Geodetic Model Version 2: Moving beyond Ridgecrest

Ekaterina Tymofyeyeva, Michael Floyd, Kang Wang, Katherine A. Guns, Kathryn Materna, Zhen Liu, Gareth J. Funning, Eric J. Fielding, David T. Sandwell, David Bekaert, Simran S. Sangha, Marin Govorcin, Alejandro Gonzalez-Ortega, & Xiaohua Xu

Submitted September 10, 2023, SCEC Contribution #13253, 2023 SCEC Annual Meeting Poster #196

The Community Geodetic Model (CGM) Working Group has been focused on investigating methods for the generation of geodetic (GNSS and InSAR) time series and velocities over Southern California, creating a set of self-consistent and well documented products, and making them accessible to the Earth science community. Our work on continued development of the CGM was done as part of a collaboration among a large number of SCEC-affiliated researchers at a number of contributing institutions. The InSAR subgroup has focused on advancing the research into improving InSAR processing techniques, establishing best practices, reaching a community consensus for the best InSAR-based deformation model, and exploring integration with GNSS. The InSAR component of the CGM, which is comprised of consensus line-of-sight deformation time series and velocities in Southern California between 2015 and 2019, including the latest corrections and uncertainties as well as the tools for working with the dataset, is available on the SCEC website: http://moho.scec.org/cgm-viewer/.

The occurrence of the July 2019 Ridgecrest earthquakes created an invaluable opportunity for detailed investigation of co- and post-seismic deformation using space geodetic data, the effect of which is particularly critical to crustal motion studies in Southern California. Any time series product that spans the earthquake event will observe an offset, which creates an obstacle to some InSAR time series algorithms. As we progress to incorporating the Ridgecrest earthquakes into the CGM, our group has worked on discussing, testing, and comparing the distinct methods used by the participating working groups, including varying versions of a pure InSAR time series approach to solve for the earthquake offset, as well as workflows that estimate coseismic and postseismic contributions in the time series using physical models. In this presentation, we show the comparison between the methods employed by the different research groups, as well as a preliminary version of the consensus continuous InSAR time series spanning the earthquakes. In addition, we present a summary of the plans of our working group going forward, including our proposed strategies for aligning InSAR and GNSS data, the extension of the coverage of our model in both space and time, and our intentions regarding workflows that will allow us to make more frequent and regular updates of our model.

Key Words
InSAR, CGM, deformation, collaboration

Tymofyeyeva, E., Floyd, M., Wang, K., Guns, K. A., Materna, K., Liu, Z., Funning, G. J., Fielding, E. J., Sandwell, D. T., Bekaert, D., Sangha, S. S., Govorcin, M., Gonzalez-Ortega, A., & Xu, X. (2023, 09). InSAR Community Geodetic Model Version 2: Moving beyond Ridgecrest. Poster Presentation at 2023 SCEC Annual Meeting.

Related Projects & Working Groups
SCEC Community Models (CXM)