The 2022 M w 6.7 Menyuan earthquake: a cascade rupture reveals the high stress accumulation on the west section of Tianzhu seismic gap

The January 8th 2022 menyuan earthquake(Mw6.7) occurred along major boundary fault zone in the northeastern Tibetan Plateau.In this study, we derived the co-seismic deformation from pixel offset tracking (POT) and interferometric synthetic aperture radar (InSAR) by using Sentinel-1 data. The inteferograms pattern shows that coseismic deformation is dominated by horizontal movements with the maximum displacement are over 0.5m in both tracks and POT results. Then we inverted the geometry parameters of the causactive fault and the slip distribution of the fault plane based on the finite dislocation model. The result shows the seismogenic fault has an average strike of 108.0 ◦ and a northeast dip angle of 83 ◦ . moreover, the coseismic slip is primarily concentrated on the lenglongling fault with on main asperity of 10 X 23 km and the maximum slip of 3.5m at depth of 4km as well as rupture the eastern of the tuolaishan fault with a small area of 5×5 km at depths of 0–8 km. On the basis of the dCFS results caused by historical earthquakes in tuolaishan fault and geodetic-derived slip rate of the tuolaishan fault, we emphasize the potential seismic risk on western Tianzhu gap is high.