SEISMIC IMAGING BENEATH SUMATRA ISLAND AND ITS SURROUNDINGS, INDONESIA, FROM LOCAL-REGIONAL P-WAVE EARTHQUAKE TOMOGRAPHY

Sumatra Island and its surroundings, Indonesia, are one of the most active tectonics in world. The Aceh-Andaman earthquake, destructive earthquakes world, occurred there. It has attracted many earth scientists to apply various methods, including seismic tomography, understand island’s subsurface structure tectonic system. This study is first delineate imaging beneath island surroundings using a local-regional earthquake catalogue from Indonesian Agency for Meteorology, Climatology, Geophysics (BMKG) seismicnetwork. tomographic P-wave (Vp) conducted this successfully delineated subduction slabs (high Vp), partial melting zones (low volcanic arcs Sumatran Fault Vp). relationship between zone arc on can be seen several vertical sections where occurs at depth about 100 km, which functions as magma feeding some volcanoes island. oceanic slab model also exhibits more pronounced steeper slope towards southern regions Island, possibly attributed slab’s aging process that direction. results highlight importance BMKG network structures Indonesia’s archipelago, especially main islands such Sumatra.