资源环境科技发展态势分析平台

We investigate the spatiotemporal variations of the stress field and the deviatoric stress associated with the 2019 Ridgecrest earthquake sequence using the USGS earthquake focal mechanisms. We find that while the M 6.4 foreshock causes no notable stress changes, the stress field adjustment due to the M 7.1 mainshock exhibits significant spatial complexities. The area of large stress change is generally correlated with the fault segments with large coseismic slip. Although there are no resolvable stress changes at the two terminal ends of the mainshock, the mainshock produces a ~ 5° clockwise rotation of the maximum horizontal stress (SHmax) near the M 6.4 foreshock epicenter. The inferred deviatoric stress is approximately 8.0 MPa, almost equivalent to the coseismic stress drop of 7.4 MPa in its epicenter area. Such nearly complete stress release is supported by the post‐seismic stress heterogeneity near the mainshock epicenter.