Slab tear and tensional fault systems in the Sunda–Andaman Benioff zone: implications on tectonics and potential seismic hazard

Abstract

Transverse slab tear faults and longitudinal trench parallel extensional faults present on the top part of Benioff zone in Sunda–Andaman arc between latitude 6°–15°N and longitude 90°–98°E are marked by seismotectonic analysis using contemporary data related to regional tectonics, seismicity, centroid moment tensor (CMT) fault plane solutions, etc. Characteristics of ten numbers of transverse slab tear faults is taken from our previous studies, whereas four numbers of longitudinal trench parallel extensional faults are marked by the present study. These two sets of fault systems make high angle between them and tectonically complement each other. The disposition, origin, tectonic framework, depth of penetration and seismotectonic evaluations of the fault systems are analyzed. An effort is made to identify the potential seismic hazard in the zone between trench and forearc containing Andaman Group of Island.