Permalink : http://hdl.handle.net/2115/60915

JaLCDOI : 10.14943/gbhu.79.9

Measurements for vertical gradient of gravity were carried out on mountain slope of active Tokachidake volcano. Round-trip gravity measurements at a lower and an upper surfaces of a tripod with about 0.97 m height difference using four SCINTREX CG5 gravimeters were conducted. Estimated gravity gradient were 0.285 to 0.290 mGal/m. These values were smaller than the Free-air gradient of 0 .3086 mGal/m, which is usually referred. Effect from local terrain was suggested because of precipitous topography. Estimations of gravity gradient near active crater by direct measurements and numerical simulation are desirable to evaluate ground deformation effects in gravity change due to volcanic activity.