Abstract
Abstract The Fukuoka area is located in the southwestern part of Japan. The Yokote-Ijiri area, located in the southern part of Fukuoka city, has several low-temperature geothermal systems, including eleven hot springs. From 1996 to 2008, the Fukuoka area was investigated by gravity survey, using Scintrex CG-3 and CG-3M gravimeters, in an attempt to delineate its subsurface structure. The surveys were intended to improve the understanding of the relation between the geothermal systems and the subsurface structure as well as to locate the active faults in the surveyed area, which are responsible for generating large earthquakes. The gravity data were analyzed using integrated gradient interpretation techniques, such as the Horizontal Gradient (HG), Tilt Derivative (TDR), and Euler deconvolution methods. With these techniques, many faults were detected, including the famous Kego fault, which is an active fault in Fukuoka city. A 2-D gravity model was constructed to show the relationship between the faults and the geothermal systems. The results of the present study will hopefully lead to an understanding of the relationships between the interpreted faults and the location of the low-temperature geothermal systems and possibly aid in future geothermal exploration of the area.
Highlights
Several low-temperature hot springs are located in the Yokote-Ijiri area of the southern part of Fukuoka city
Many scientists believed that the earthquake occurred along the extension of the Kego fault, which runs from the northwest to the southeast under the Sea of Genkai
Eleven hot springs were detected in the Fukuoka area
Summary
Several low-temperature hot springs are located in the Yokote-Ijiri area of the southern part of Fukuoka city. Fujimitsu et al (2003) stated that the hot springs were likely generated by a specific subsurface structure of unknown origin. Karakida et al (1994) suggested that an active fault, named the Kego fault, passes through the Yokote-Ijiri area, but no scientific investigations have been conducted to locate the Kego fault. The aim of this study is to delineate the subsurface structure of the Fukuoka area and to determine its relationship with low-temperature geothermal systems by applying gradient interpretation methods to the available gravity data. The results of the present study will delineate the boundaries of the Kego fault, which is of interest to those studying the seismology of the area
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
