17:15 〜 18:30
[SEM12-P02] Three-dimensional inversion of magnetotelluric data in a geothermal area near Hakkoda volcano
キーワード：地磁気地電流法、3次元インバージョン、地形、地熱探査
Three-dimensional (3D) inversion was carried out to a magnetotelluric (MT) dataset obtained in a geothermal area on a western flank of northern Hakkoda volcano, Aomori Prefecture, Japan. The 3D inversion code used is WSINV3DMT (Siripunvaraporn and Egbert, 2009). The number of MT stations is 34, and the number of frequencies used as observed data in the inversion is 15, ranging from 0.0067 Hz to 115 Hz. The surface topography was included in the finite-difference mesh with a small vertical discretization in order to achieve accurate forward modeling. The size of a cell at the ground surface for the elevation range where the MT stations are located was set to 150m x 150m x 10m, basically. The resultant 3D model indicated a good correlation with logging data in a few boreholes obtained in the surveys about 30 years ago. The procedure of the 3D inversion and geothermal interpretation of the model are presented in this paper.