Poster #181, SCEC Community Models (CXM)

Current status and future plans for the Community Geodetic Model (InSAR) products

Ekaterina Tymofyeyeva, David T. Sandwell, Xiaohua Xu, Zhen Liu, Kathryn Materna, Kang Wang, Gareth J. Funning, David Bekaert, & Michael Floyd
Poster Image: 

Poster Presentation

2020 SCEC Annual Meeting, Poster #181, SCEC Contribution #10713 VIEW PDF
The goals of the Community Geodetic Model (CGM; areis to create a consensus model of the crustal motions in Southern California at high spatial and temporal resolutions and to provide a product that is easily accessible to the wider scientific community. Constraining the ground deformation associated with earthquake cycle processes, long-term tectonics, hydrologic cycles, geothermal features, and other processes is crucial to understanding seismogenic phenomena in Southern California. With the launch of Sentinel-1 SAR satellites, which provide frequent acquisitions and tight orbital control, new avenues of InSAR time series techniques have become possible. ...Building upon previous work towards CGM development, we present InSAR line-of-sight (LOS) time series and velocities from Sentinel-1 descending track 71 in Southern California from 2015 to the Ridgecrest earthquakes in mid-2019, as a proof of concept before expanding the products to cover all tracks within the SCEC region.

In order to establish a consensus community model, we evaluate the impact of diverse processing techniques on the time series and velocity results, with the goal of establishing best practices for the computation of InSAR time series. We create a joint model by combining six different time series and velocity results, 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. Corrections we consider include those similar to GNSS processing, such as tropospheric delays and solid Earth and ocean tide loading, which will ultimately facilitate the combination of the InSAR CGM with GNSS products. Future work will involve completing the processing of these products for the full region and aligning them with the CGM GNSS results to create a consistent reference frame for geophysical interpretation.