PROCEEDINGS, Thirty-Sixth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, January 30 - February 1, 2012 SGP-TR-194 RECHARGE ELEVATION OF HOT SPRING STUDY IN THE MT. MUAYAT AT THE KOTAMOBAGU GEOTHERMAL FIELD, NORTH SULAWESI, INDONESIA USING THE STABLE ISOTOPE 18O AND 2H Hendra RIOGILANG.1, 3, Ryuichi ITOI.1, Sachihiro TAGUCHI2 1Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-Ku, Fukuoka 819-0395, Japan 2Department of Earth System Science, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-Ku, Fukuoka 814-0180, Japan 3Department of Civil Engineering, Faculty of Engineering Sam Ratulangi University, Manado 95115, Indonesia
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[email protected] ABSTRACT Water samples of Mt. Muayat consisting of hot In the geothermal area, the rain water from that spring and river water were analyzed stable isotope. elevation come to the surface, to infiltrate and Rain water was also collected using a rainwater percolate into the ground, flowing in the shallow collector of open air type from five locations with aquifer, receipt of warming up by an underground elevations ranging from 556m to 1500m during heat source and discharges to the lower elevations or March 2010 to June 2010. Six hot spring waters of continuing to the depth reach the reservoir of Mt. Muayat have shift of less than 2‰. This implies geothermal fluid and flows up again to the surface as that the origin of hot spring water is mainly meteoric the cycles. Meteoric waters are entering the ground water. The meteoric water has recharged to the and are heated to a certain extend depending on the ground of Mt.