The Recent Small Earthquakes around Lembang Fault, West Java, Bandung, Indonesia

Abstract

On May 14^th and 18^th, 2017 felt earthquakes were occurred around western part of Lembang area, Bandung, West Java, Indonesia with magnitude of M2.8 and M2.9, respectively. The first earthquake (M2.8) was felt by some people around epicenter area. We determined the earthquake location through re-picking of P-and S-wave arrival time recording by Indonesian Agency for Meteorological, Climatological and Geophysics (BMKG), network. Earthquake location was determined by using Hypoellipse code that employs a single event determination method. We also conducted focal mechanism analysis to estimate the type of fault slip. The results indicate the hypocenters location in the north and south of the western part of Lembang fault with the focus depth of ∼ 5 km, respectively. Source mechanism solutions showed the type of earthquake is strike-slip fault. The occurrence of two recent small earthquakes need more attention about the activity of Lembang fault. The destructive earthquake related to displacement of the fault occurred on August 28, 2011 (M3.3) located at the western end of the Lembang fault. For further study, we have been deploying 6 temporary seismometers stations around Lembang fault in attempt to detect small events and to delineate subsurface seismic structure by applying tomography method.