2-D Resistivity Structure of Cubadak Geothermal Area Revealed from Magnetotelluric Data

Cubadak area in Pasaman Regency, West Sumatra, Indonesia is one of many potential geothermal areas in Indonesia. This paper deals with resistivity structure beneath Cubadak area obtained from magnetotelluric data. The subsurface resistivity image of Cubadak reveals the components of Cubadak geothermal system clearly such as the altered clay having very low resistivity values, the possible reservoir zone having intermediate resistivity values underlying the altered clay as well as the indication of geological structures controlling the system. The top boundaries of the reservoir vary from elevation of 250 m to -500 m above sea level.