PENENTUAN HIPOSENTER GEMPA VOLCANO-TECTONIC MENGGUNAKAN METODE MULTIPLE SIGNAL CLASSIFICATION 3 COMPONENT(MUSIC 3C) PADA GUNUNG MERAPI YOGYAKARTA; DETERMINATION OF VOLCANO - TECTONIC HYPOCENTER USING MULTIPLE SIGNAL CLASSIFICATION 3 COMPONENT (MUSIC 3C) METHOD APPLICATION TO MERAPI VOLCANO YOGYAKARTA

HABIBAH, ERPIN, Imam Suyanto

2016 | Skripsi | FMIPA

Merapi volcano is the one of active volcanoes in Indonesia that has eruption phenomena periodically and located at dense inhabitant. Hence it is important to monitor the activities as the first mitigation. Exertion determination of hypocenter of seismo-volcanic to understand volcano activity using classic method has constraint in picking time arrival of P wave and S wave. This research develop a new framework of source localization method based on the MUSIC 3C algorithm. Input data used for this study is estimation of time arrival P wave plus 20s. The fundamental scheme of the MUSIC 3C method resulting the cross-spectral matrix of 3C array data, corresponding to the first seismic signal arrivals, provides of useful vector components of slowness from the seismic source there are azimuth and incident angle. Real data used in this study was collected during seismic measurements with two seismic arrays (KLA and MEA) in 2015, whose the experiment conduced by BPPTKG Yogyakarta. The vector components (azimuth and incident angle) from the seismic source used to construct 2D model of epicenter and hypocenter of source which associated with the fracture as a consequence of magmatic activity. Analysis model showed a complex mechanism of three Volcano-Tectonic type B. The sources are found at SW-NE direction located at depths of 961 m, 1086 m and 886 m beneath the summit with error ±183 m. It is estimated that the sources are associated with local fracture caused by shallow magma storage activity. According to VT event processing frequency dominant obtained 3,6-6 Hz, azimuth of 120°-170° at KLA dan 240°-250° at MEA with error ±13°, incident angle of 70°-80° at KLA dan 50°-60°at MEA with error ±21° and velocity apparent of 2100-2900 m/s at KLA and 2200-2900 m/s di MEA with error ±367 m/s.

Kata Kunci : N