Spectra analysis for source dynamic identification of deep volcano tectonic underneath mounth Sinabung, North Sumatera

Spectra frequency of VT indicates the effective stress of volcanic activity. Spectra frequency of VT indicates the effective stress of volcanic activity. These spectra parameters could be applied to determine source and the dynamics of the source of the VT earthquake. This study analyzed the spectra VTA earthquake in the Sinabung volcano between July and November 2013, by applying the FFT algorithm based on the Brune model. Analysis show that the corner frequency of VTA earthquakes of Sinabung volcano were dominated by frequency of 12 – 13 Hz. Hypocenter positions were at a depth of 2 km - 20 km from the summit. Epicenter positions were spread towards the Northwest from the summit, i.e to the Lake Kawar direction. Most of the VTA source mechanisms are strike slip and oblique, and small portion of normal faults and reverse faults. Energy accumulation before the eruption was occurred from July to August and after eruptions in October. On this October accompanied by the formation of a new dome and followed by a magmatic eruption in November. Fractures that triggered the eruption was happened on September 12nd, 2013 and ended on September 22nd.