Magnetotelluric survey and three-dimensional resistivity structure in and around the Niseko area, southwestern Hokkaido

Supercritical geothermal systems (SGS) have the potential to drastically increase geothermal power generation. The New Energy and Industrial Technology Development Organization (NEDO, Japan) has recently started to research and develop supercritical geothermal power generation. Our team conducted a field survey and data collection at three areas in Japan, to characterize the SGS and evaluate the potential for supercritical geothermal power generation. Here, we present a three-dimensional resistivity structure by observing 112 magnetotelluric and 4 telluric sites in and around the Niseko area, southwestern Hokkaido. The final resistivity structure showed a dominant sub-vertical conductor beneath the central part of the Niseko volcanic group. We inferred that the supercritical geothermal fluids possibly exist below an altitude of about-3 km inside or edge of the conductor.