Tectonic Evolution and Seismic Hazards in Bangladesh: Insights from Geophysical and Geotechnical Studies

Abstract

Bangladesh is located at the convergence of the Indian, Eurasian, and Burmese plates, a tectonic setting that makes the country one of the most seismically vulnerable regions in South Asia. The regional framework is characterized by active subduction along the Indo-Burmese Arc, strike-slip faulting, and crustal shortening across thrust systems. Among these structures, the Dauki Fault at the southern margin of the Shillong Plateau plays a central role in accommodating crustal strain and controlling regional seismicity. Additional features, including the Naga-Disang thrusts and several concealed intra-basin faults, further contribute to the high hazard potential. This study integrates geophysical and geotechnical approaches to improve seismic hazard understanding in the Bengal Basin. Geophysical datasets, including seismic reflection, gravity, and magnetotelluric surveys, delineate crustal deformation, fault propagation, and basin dynamics. Complementary geotechnical assessments, based on soil stratigraphy, shear-wave velocity (Vs30) profiles, and liquefaction analyses, reveal that unconsolidated alluvial and deltaic deposits significantly amplify ground motion. Probabilistic Seismic Hazard Analysis (PSHA) indicates that northeastern and southeastern Bangladesh, being proximal to active tectonic structures, face the greatest hazard, with peak ground accelerations exceeding 0.3g under worst-case scenarios.