ANALISIS KARAKTERISTIK SPEKTRAL KEGEMPAAN VULKANIK GUNUNGAPI LEWOTOLO PADA KRISIS JANUARI 2012 DAN HUBUNGANNYA DENGAN GEMPABUMI TEKTONIK DI DAERAH SEKITARNYA; SPECTRAL CHARACTERISTIC ANALYSIS OF VOLCANIC SEISMIC AT LEWOTOLO VOLCANO ON THE CRISIS OF JANUARY 2012 AND ITS CORRELATION WITH TECTONIC EARTHQUAKES SURROUNDING AREA

JULIANY NINGSIH MOHAMAD, Kirbani Sri Brotopuspito

2014 | Disertasi | PROGRAM STUDI S2 ILMU FISIKA

Analysis of volcanic seismic activity at Lewotolo volcano (8° 16' 18" S and 123° 30' 18" E) on the crisis 2012 and its correlation with tectonic earthquakes at its surrounding area has been done. The aim of this study is to analyze the volcanic seismic activity on volcanic crisis in 2012, to determine b - value, focus mechanisms, and Coulomb stress changes of tectonic earthquakes. Data of volcanic seismicity obtained from PVMBG on July 2011 - June 2012. Tectonic eartquake data obtained from the International Catalogue Sesmology Center (ISC) and the U.S. Geological Survey / National Earthquake Information Center (USGS / NEIC) since 1965 to 2013. Spectral analysis of volcanic earthquakes (type A and type B) is used to obtain the dominant frequency. Tectonic eartquake data were used to determine the b-value, focus mechanism and Coulomb stress changes. The reseacrh found that the dominant frequency volcanic earthquakes is 11 to 12 Hz . The b-value before the crisis is 2.3 ± 0.4, towards the crisis is 1.0 ± 0.1 and after the crisis is 1.7 ± 0.3. The research area are dominated by normal and reverse faults. Coulomb stress changes explain the increase of Lewotolo volcanic activity on January 2012 did not correlate directly with the tectonic earthquakes at its surrounding area

Kata Kunci : Lewotolo; b-value; vulkanik; mekanisme sumber; perubahan stress Coulomb