Analysis of M 5.3 Sumbawa, Indonesia earthquake 2020 and its aftershocks based on hypocenter relocation from BMKG seismic stations

Abstract The 2020 Sumbawa earthquake of moderate magnitude (M 5.3) produced very significant aftershocks. Based on the computation Utsu’s method, those aftershocks would be ended after 20th day. Those earthquakes along 20 days were relocated using double-difference method. relocation results show southwest-northeast orientation and getting deeper into northwest direction. two directions strike dip from fault plane which was consistent with focal mechanism released by Indonesian Agency for Meteorology, Climatology, Geophysics (BMKG). showed majority occurred at a depth shallower than km. depths fit previous study showing crustal thickness beneath Island that about 28 We also found splay faults propagating to decollement structure. This is beneficial disaster mitigation especially in updating active Island.