Source mechanism, seismicity clustering and tectonic implications of the 2025 Mw 7.1 Dingri earthquake, southern Tibet

Abstract

The 2025 Mw 7.1 Dingri earthquake in southern Tibet was a normal faulting related devastating earthquake that occurred on January 07, 2025. We analyze the temporal nature of earthquake activities and the source mechanisms using stochastic moment tensor (MT) inversion via a regional teleseismic network with rotated seismic waveform at a distance up to 4000 km from the epicenter. We used earthquake catalog data from January 2005 up to January 2025 and performed cluster analysis in terms of space-time-depth-magnitude (STDM) time series. The breaks in the time series indicate preshock and aftershock events before and after the Dingri and other earthquakes. The wavelet analysis is utilized to process the logarithmic STDM time series. The co-seismic line-of-sight (LOS) displacement analysis (along the LOS) was also performed using the differential interferometric synthetic aperture radar (DInSAR) technique on the Sentinel-1 pre- and post-earthquake time-series data for the 2025 Dingri earthquake. For DInSAR results, a coherence threshold was set to deduce the misinterpretations in displacement values often caused by the phase decorrelation among the image pairs. The InSAR phase analysis determined ∼0.11 m to 0.44 m of uplift and a subsidence of up to 1.49 m near the epicenter. Results show various mechanisms for Dingri earthquakes, the potential of the proposed STDM model, and a statistical analysis for future predicted earthquakes in any region can be undertaken in the same line.