PEMODELAN 3D DATA GAYA BERAT UNTUK MENGIDENTIFIKASI SUMBER PANAS DAERAH PANAS BUMI SIPOHOLON, SUMATERA UTARA

Abstract

Sipoholon area, based on its surface manifestations and geological setting, is a potential area of geothermal resource. Unfortunately, this potential has not been developed for power plant purpose, because the absence of conceptual model, information of working system, and type of heat source of this area. At 2005, series of gravity investigation has been done in this field. The gravity data were measured from 230 stations covering an area of about 16 km x 14 km. Therefore, the author has done 3D modeling of the same gravity data to identify the heat source of this area based on 3D model of density distribution. This modeling use 3D inversion method of Grablox software which combine 2 (two) inversion method namely singular value decomposition (SVD) and Occam inversion. The result of this modeling show that there is a presence of high density blocks whose value between 2,80 – 3,00 g/cm3 which located in the southern and eastern with > 2 km of depth. These blocks is interpreted as an intrusive body and considered as the heat source of Sipoholon geothermal system. The result of this study can be used as an initial information in making conceptual model of geothermal system of this area.