SEGJ Technical Conference

Estimation of Underground Structure Using Densed Gravity Survey at Northeastern Part of Fukuoka City

Abstract There are some faults at northeastern part of Fukuoka city. Umi fault is an active fault which is discovered at northeastern part of Fukuoka city recently, but the detailed structure of the fault is not shown. We have carried out the densed gravity survey at 1891 points, using Scintrex CG-3 and CG-3M gravimeters at Fukuoka city. Using these data, we made a Bouguer anomaly map to estimate underground structure at northeastern part of Fukuoka city. We detected some high gradient zones of Bouguer anomaly. These high gradient zones of Bouguer anomaly were caused by structural boundaries such as faults. We carried out 2D structural analysis and 3D structural analysis to estimate underground structure. From these results and faults at northeastern part of Fukuoka city, we consider the relation between structural boundaries due to gravity anomaly and assumed faults.