Shallow Ground Characterization Of Gedongsongo Geothermal Field Based On Microtremor Data

The research has been conducted in the Gedongsongo manifestation area, Mount Ungaran Geothermal Field. This study aims to characterize shallow subsurface manifestations using microtremor data. Microtremor data were recorded Candi Village, Bandungan Subdistrict and Jubelan Sumowono Subdistrict, Semarang Regency. recording can be done directly a seismometer with three components. measurement is by simultaneous at two or more points, one of points selected an area that hard rock structure avoid frequency amplification due ground motion. spectrum ratio other areas will compared rock, so as obtain site response microtremors. Based on Vp/Vs values, most field composed very stiff types. distribution Poisson's values ranges from 0.20 - 0.50 steaming range 0.10 0.47. it shows partly water prospect form hot springs, while dry rocks filled steam gas.