Effectiveness of Spatially Dense MT Measurements for a Study of Fine Resistivity Structure

A Case Study at Hohi Sugawara, Kyushu, Japan

抄録

One defect of the MT method is its poor resolution of subsurface resistivity structure. We attempted to improve this situation by carrying out spatially continuous MT measurements along a straight line crossing a target area. Here we report the results of our measurements in the Hohi Sugawara area, central Kyushu, Japan. AMT data were also acquired at all the MT sounding sites. Comparison with logging data indicates that AMT data are necessary to estimate the shallow resistivity which is important for static correction in two-dimensional modeling. Analyses of MT data revealed some anomalous areas which seem to be closely related to the geothermal reservoir structure. If we incorporate other data such as logging data for geothermal wells, gravity data, and geological data, we can infer a more detailed reservoir structure.