The growth of forearc basins along the oblique western Sunda subduction zone and its implication to seismic hazards

Abstract

The growth of forearc basins in an oblique subduction system has been proposed to have related to strike-slip faulting due to strain partitioning. We reviewed several models of the primary controls on the evolution of the forearc basin in the western Sunda subduction zone: formation of the sliver plate, the occurrence of continental backstop, development of strike-slip faults traversing the basins, flexure, and uplift of the forearc high. It appears that the major control of the subsidence of the basin is due to the uplift of forearc high. However, the present day morphology of the forearc high and forearc basin seems to have been largely controlled by the subduction of roughness morphology on the oceanic crust. The occurrence of subducting bathymetric highs on the oceanic crust is likely to have contributed on the spatial distribution of large earthquakes in the forearc region.