MIKROZONASI TINGKAT POTENSI RISIKO BENCANA GEMPABUMI DI WILAYAH KABUPATEN CILACAP BERDASARKAN DATA MIKROTREMOR

PURNAMASARI, TRI WULAN, Wiwit Suryanto

2016 | Skripsi | FMIPA

Microseismic survey has been carried out in the district of Cilacap on November 13th to 20th 2014 by Center for Volcanology and Geological Hazard Mitigation. This research was conducted to provide the values of Peak Ground Acceleration (PGA) and vulnerability indeks (Kg) as hazard factor of earthquake. The received data consists of 104 measurement points of microtremor data. The calculation of the PGA value used the dominant period data as the input. The dominant period is calculated by using the Horizontal to Vertical Spectral Ratio (HVSR). The calculation of the value of PGA is obtained by empirical method for the Kanai earthquake on January 25, 2014 with a moment magnitude of 6.1. The result of data processing shows that the district of Cilacap has a value of PGA between 6,3 – 167,86 gal and vulnerability indeks between 0,16 – 158,45. Vulnerability factor is population density every district in Cilacap, and capability factors is number of health facilities every district in Cilacap. The conclusion, Cilacap in general has a high risk of low to high risk potential. The risk potential will be used to provide recommendations within the planning areas in the study area.

Kata Kunci : microseismic, Peak Ground Acceleration (PGA), HVSR, Kanai method, earthquake.