SOURCE PARAMETER ESTIMATES OF THE 4 NOVEMBER 2016 mb= 4.7 EARTHQUAKE NEAR LAWU MOUNTAIN IN EAST JAVA, INDONESIA

Due to its geological conditions, Indonesia is home for a series of active volcanoes and fault zones spanning over the Sunda-arc in the country. With respect to possible volcano eruptions, earthquakes, and tsunamis, recent research development has therefore covered areas (previously not classified into areas vulnerable to potential threats)that are possibly suffering from tectonic movement. These include regions in the northern East Java, where Mount Lawu exists. This work aims to estimate source parameters of the 4 November 2016 earthquake with mb= 4.7 that occurred in the region of interest. The methods were seismic data inversions using full moment tensors implemented in a MTINV software, where waveforms provided by 4 local stations from IA network: PCJI, UGM, SMRI, and KMMI were used. The results show a seismic moment of 5.03 x1022 dyne cm, corresponding to a moment magnitude of Mw4.40, variance reduction of 60.8% with a 0.9% ISO component, a 73.8% CLVD component and 25.3%, DC component, and a centroid depth of 33 km. These suggest a complex fault interaction in the source mechanisms with the volcanoes earthquake is found to be complex interaction between fault about mountain Lawu and mountain Lawu