Kinematic Rupture Model of the 2021 M6.0 Antelope Valley Earthquake from Joint Inversion of Seismic, GNSS and Sentinel-1 InSAR Data

The July 2021 magnitude 6.0 Antelope Valley earthquake in eastern California is associated with the complex seismically active Walker Lane shear zone. This area is characterized by normal and strike-slip faulting with the July 2021 mainshock inferred to have ruptured on a north-south striking normal fault. The observations from this moderate magnitude earthquake provide an opportunity to examine slip behavior occurring within a diffuse zone of deformation. We perform kinematic slip inversions using seismic and geodetic observations to model the coseismic rupture process of the Antelope Valley mainshock. Broadband and strong motion stations from the Berkeley Digital Seismograph Network and Nevada Seismic Network provide regional seismic observations. SAR images from the Sentinel-1 satellite ascending and descending acquisitions over the mainshock area are utilized to produce a coseismic interferogram. Regional 5-Hz GNSS recordings are also used with the closest station to the event within 40 km. We test fault parameters from published CMT solutions to obtain a best fitting finite-fault model from joint inversion of velocity waveforms, GNSS displacement waveforms, and InSAR line-of-sight offsets. We conclude by discussing the fault rupture implications characterized by the coseismic slip distribution and aftershock locations for the regional deformation field and hazards.