Community Geodetic Model: Current status of the consensus InSAR model for deformation time series and velocities in Southern California

Ekaterina Tymofyeyeva, Michael Floyd, David Bekaert, Gareth J. Funning, Katherine A. Guns, Zhen Liu, Kathryn Materna, David T. Sandwell, Kang Wang, & Xiaohua Xu

Published August 16, 2021, SCEC Contribution #11641, 2021 SCEC Annual Meeting Poster #019

The Community Geodetic Model (CGM; https://www.scec.org/research/cgm) aims to create a consensus model of the crustal motions in Southern California at high spatiotemporal resolution, and provide the model as a product that is accessible to the wider scientific community. The InSAR CGM working group has been building upon previous work towards CGM development by comparing the impact of different methodologies on the time series and velocity calculations and establishing best practices, as well as assembling and testing an InSAR CGM product.

We present InSAR line-of-sight (LOS) time series and velocities from four overlapping ascending and descending Sentinel-1 Tracks over Southern California, spanning the time from 2015 to the Ridgecrest earthquakes in mid-2019. In order to establish a consensus community model, we combine six different time series and velocity solutions, provided by groups at SIO/UC San Diego, UC Berkeley, USGS, UC Riverside, and NASA JPL. In addition to the combined CGM, we present the individual models, and quantify uncertainties due to the variation in InSAR processing methods and applied corrections. We find that a combined model improves on the individual models by mitigating methodology-specific artifacts and emphasizing common features that are likely to represent real deformation signals.

Future work will involve extending the time series and computing the interseismic velocities past the Ridgecrest earthquakes, aligning the InSAR results with those from the GNSS CGM working group to create a consistent reference frame for geophysical interpretation, resolving 3-dimensional motions from a combination of InSAR measurements from different lines of sight with GNSS observations, and making the CGM product available online.

Citation
Tymofyeyeva, E., Floyd, M., Bekaert, D., Funning, G. J., Guns, K. A., Liu, Z., Materna, K., Sandwell, D. T., Wang, K., & Xu, X. (2021, 08). Community Geodetic Model: Current status of the consensus InSAR model for deformation time series and velocities in Southern California. Poster Presentation at 2021 SCEC Annual Meeting.

Related Projects & Working Groups
SCEC Community Models (CXM)