Structural controls on coseismic rupture revealed by the 2020<i>M</i>w 6.0 Jiashi earthquake (Kepingtag belt, SW Tian Shan, China)

SUMMARY The Kepingtag (Kalpin) fold-and-thrust belt of the southern Chinese Tian Shan is characterized by active shortening and intense seismic activity. Geological cross-sections reflection profiles suggest thin-skinned, northward-dipping thrust sheets detached in an Upper Cambrian décollement. 2020 January 19 Mw 6.0 Jiashi earthquake provides opportunity to investigate how coseismic deformation accommodated this structural setting. Coseismic surface resolved with Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) centred on back limb frontal anticline. Elastic dislocation modelling suggests that causative fault located at ∼7 km depth dips ∼7° northward, consistent inferred position Our calibrated relocation main shock hypocentre eastward, unilateral rupture fault. narrow slip pattern (length ∼37 but width only ∼9 km) implies there a strong or lithological control extent, updip propagation possibly halted abrupt change dip angle where branch off A discrepancy between constrained InSAR teleseismic waveform (∼7 well-relocated aftershocks (∼10–20 may faults within sediments above décollement exhibit velocity-strengthening friction.