| 講演要旨(和文) | | 1970年噴火以降の秋田駒ヶ岳火山の状況推移を地球物理学的諸観測によって追跡してきた．その一つとして定点重力観測が1977年から繰り返し実施された．注目すべき重力変化が1970年火口のある中央火口丘の女岳の山頂・山腹域で観測された．女岳域の地熱活動の減退に伴い重力は1977年から1998年にかけて増加し，近年の地熱活動の再活発化に伴い減少傾向に転じた．各時期の重力変化は地盤の隆起・沈降によるものと解釈される． |
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| | 講演要旨(英文) | | Volcanic condition of Akita-Komagatake volcano after the eruption of 1970 has been monitored by geophysical methods. As one of them gravity observation has been made repeatedly at fixed points since 1977. Remarkable gravity variation was observed at the top and side of the Medake which is the central cone with the 1970 crater. The gravity increased with decay of thermal activity in the Medake area from 1977 to 1998, and then has changed to tendency of decrease with reactivation of the thermal activity for the last several years. The gravity variation in the respective stages is interpreted to be caused mainly by uplift and subsidence of the ground surface. |
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