This project is part of an integrated geothermal exploration concept, which includes structural geology, geochemistry, and seismology for the geothermal field near Sipoholon, North Sumatra Province, Indonesia. The study area is located in the Tarutung basin, which is part of the active the strike slip Sumatra Fault, in the vicinity of the Imun and Martimbang inactive volcanoes. Magnetotelluric data were measured in an area of 22 x 25 km2 (see figure). 2D and 3D inversions are carried out to understand and characterize the reservoir and the heat source of this geothermal system. By joint interpretation of the MT results together with data from structural geology, geochemistry, and seismology we intend to develop a conceptual model of the geothermal system (reservoir, heat source, fluid path, border/ cap/ boundary) which is still disputed.

Time Frame

• 10/2009 -09/2013

Principal investigators

• PD Dr. Oliver Ritter (GFZ)
• Dr. Gerard Muñoz (GFZ)

Personnel

• Sintia Windhi Niasari (GFZ)

Cooperations

• GFZ (coordinating role)
• Leibniz-Institut für Angewandte Geophysik – LIAG
• Georg-August-Universität Göttingen
• Bundesanstalt für Materialforschung und –prüfung – BAM
• Karlsruher Institut für Technologie - KIT
• Geological Agency of Indonesia Bandung - PSDG

Methods & Equipment   

• Magnetotellurics, geothermal exploration
• SPAM Mk IV real time instruments
• induction coils (Metronix)
• Ag/AgCl electrodes (GFZ)

Publications/Results 

• Windhi, S.; Muñoz, G.; Muhammad, K.; Suhanto, E.; Sugianto, A.; Ritter, O. (2011): Magnetotelluric Exploration of the Sipoholon Geothermal Field, Indonesia. 24. Schmucker-Weidelt-Kolloquium für Elektromagnetische Tiefenforschung (Neustadt/Weinstraße 2011).

Acknowledgements  

• The project is funded by the German Federal Ministry of Education and Research (BMBF, 03G0753A), the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences and PSDG.
• MT Instruments for the field campaign in 2011 were provided by the magnetotelluric component of the Geophysical Instrument Pool Potsdam (GIPP-MT).
• MT Instruments for the field campaign in 2010 were provided by the PSDG - Geological Agency of Indonesia Bandung.

Additional information

• Leibniz Institute for Applied Geophysics - Project information about seismic exploration and safety risk study for decentralised geothermal plants in Indonesia
• Field work: 07/2011 (GFZ) and 2010 (PSDG)