Geometry of the Décollement Below Eastern Bangladesh and Implications for Seismic Hazard

Eastern Bangladesh sits on the seismically active Chittagong-Myanmar fold and thrust belt (CMFB), a north-trending accretionary wedge eastern side of India-Eurasia collision. Earthquakes basal décollement associated thrusts within CMFB present hazard to this densely populated region. In study, we interpret 28 seismic reflection profiles from both published unpublished sources constrain depth décollement. To convert time domain domain, integrate sonic log stacking velocity data generate time-velocity relationships for different parts CMFB. Our analysis reveals that is ∼9 km deep in northeast southeast Bangladesh, but shallows ∼5 east-central Bangladesh. The has an area 7.25 × 104 km2 (∼150 450 km), making it capable Mw 8.5 earthquake. However, warped geometry fault might act as rupture barrier were large earthquake occur combined model lay groundwork future studies address segmentation, ground shaking, modeling Finally, use our compiled set analyze evolution kinematics We observe folding style failure mode varies, mainly ductile deformation foreland brittle hinterland. dual-failure modes support hypothesis region with may still be behavior.