Subsurface Deformation and Recovery From the Ridgecrest Mw 7.1 Earthquake Revealed by P ‐Wave Velocity Time‐Lapse Tomography

Abstract We investigate co‐ and post‐seismic P ‐wave velocity ( V p ) changes following the July 2019 Mw 7.1 Ridgecrest strike‐slip earthquake using time‐lapse tomography from 50,345 P ‐wave arrivals (2011–2024). Co‐seismically, V p changes correspond to the volumetric strain change lobes of the earthquake, increasing in compressional zones and decreasing in tensional zones. Post‐seismically, V p changes exhibit a reverse pattern, suggesting ongoing subsurface recovery. Notably, the Coso volcanic field, although distal to the rupture, shows significant co‐seismic velocity reduction and rapid post‐seismic recovery, likely indicating fluid migration or poroelastic effects. These results reveal the complex mechanical and hydrological responses to co‐seismic stress changes and provide important insights into post‐seismic healing processes. Our findings offer robust seismic evidence for the response of material properties to crustal deformation, contributing to improved understanding of structure changes in the earthquake process.