Thermal Anomaly, Co-Seismic Deformation and Seismic Source Parameters Estimation of June 21 2022, Afghanistan Earthquake Employing InSAR Observations

On June 21, 2022, a shallow earthquake of Mw 6.0 struck southeastern Afghanistan at the interaction of the Eurasian and Indian Plates. The earthquake was VIII (severe) intensity. It drew the attention of many seismologists and earth scientists. The presented work brings satellite-based detection of pre-earthquake transient thermal anomaly, co-seismic ground deformations estimation using InSAR (SAR Interferometry) and inversion of InSAR deformations results to estimate focal solution parameters. Near the Afghanistan earthquake, a rise of 5–7 °C from the normal temperature in both day and night Land Surface Temperature (LST) time series along the SW, NW, NE and east parts of the fault is observed using MODIS satellite thermal data. Sentinel-1A microwave satellite data with the InSAR technique is used to analyze co-seismic ground deformations for both passes, and the estimation of source parameters of the fault and slip distribution of the earthquake using the Bayesian inversion approach is carried out. InSAR-based ground deformations estimate upliftment of about 325 mm and subsidence of –160 mm. The inversion results of ground deformations show that the event might be occurred due to the left lateral slip mechanism. The fault seems to be steeply dipping in eastward with NE–SW trends at a depth of 7 km. A number of aftershocks have occurred till now in the regions as evident by the Coulomb static stress along the NE, east side of the fault. The correlation between high-stress regions using thermal anomaly before the occurrence of event and coulomb static stress map after the occurrence of event have been also observed. The total seismic moment for the event using the inversion result yields a value of 1.08 × 10 25 dyne-cm, which is equivalent to M w 5.99.