SEGJ Technical Conference

Airborne gravity measurements in Japan and some attempt for improving measuring accuracy for the study of active seismic faults

Abstract We have been working with the helicopter-borne gravity measurement for almost 10 years using a Japan-made airborne gravimeter. Our main objective is to fill in the gravity void along the coastal zones of the Japanese Islands. Since we aim at searching for active seismic faults running across the land-sea border lines of the Japanese Islands it is important to have a land-to-sea continuous map of gravity anomalies. In addition to gravity void along the coasts the marine gravity data are likely to have large errors of measurement particularly with the case of old data. It is desired that the accuracy of gravity data would be better than 1 mgal. We regard the airborne gravimetry as the only means to solve this problem. We are going to discuss on this.