Seismic gap identification along Sunda trench using mapping analysis of energy accumulation zone

摘要

Sunda trench is stretched from Andaman Island past the southern coast of Sumatra extend to southern Java and around East Nusa Tenggara and became the source of some significant earthquakes. Those earthquakes were Aceh M9.2 December 2004, Pangandaran M7.7 July 2006, and Flores M7.7 December 1992. Therefore, the awareness and preparedness toward seismic activity at the Sunda Trench must be improved and strengthened. The mapping analysis of energy accumulation zone should be done to evaluate the potency of earthquake events because the high accumulation of energy zone has a high probability release a strong earthquake. In this work, we analyze the gap of the seismic event along the Sunda Trench to discover a high accumulated energy zone indicated by low seismic activity comparing its adjacent area. We use rupture dimension data from finite fault referring existing research, earthquake catalog from 1976-2018, and slip rate of the subduction zone along Sunda Trench. The determination of high and low accumulated energy zone was done using rupture dimension mapping. This study yielded identification of low and high energy accumulation zones or seismic gap zone, and level of seismic activity, and earthquake time recurrent period at the zone.