| 講演要旨(和文) | | 本研究の目的は，秋田県南部地域の地下比抵抗構造を把握し，地震活動や地質との関係を明らかにすることである．我々は秋田県中部から南部地域で観測を行い，2次元解析の結果、以下のことが明らかになった。（1）測線西側の地下5kmより浅い所は断層や褶曲の影響を受けて低比抵抗を示す．（2）上部地殻下部の地下5kmから10kmの部分は低比抵抗を示す．（3）下部地殻は高比抵抗を示し，地下10kmから25kmに存在する．（4）上部マントルは低比抵抗を示し，その上面は日本海側で地下25km前後，内陸側では地下30km前後に存在する．（5）比抵抗境界部や高比抵抗部において地震活動が多発するが，一部では低比抵抗部でも地震が発生している． |
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| | 講演要旨(英文) | | The purpose of this study is to understand the underground resistivity structure over the south region of Akita prefecture, and moreover to understand the obvious relations among the resistivity structure, seismic activity, and geology. We conducted observation along east-west lines. As a result of 2-D analysis, the followings have been understood. (1) A part shallower than 5km underground in the west part of survey lines show low resistivity because of the influence of the faults and folds. (2) The lower part of the upper crust shows low resistivity, and exists at the depth of 10km to 20km. (3) The lower crust shows high resistivity and exists at the depth of 10km to 25km. (4) The upper mantle shows low resistivity and its upper boundary exists at about the depth of c.a. 30km on the inland side and at the depth of c.a. 25km on the Sea of Japan side. (5) Seismic activities occur often at resistivity boundary and high resistivity part, however some activities are found even in low resistivity part. |
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