High-resolution gravity survey in the Fukui plain, central Japan

Authors: Shigeo Okuma and Masahiko Makino

Abstract: A high-resolution gravity survey was conducted to reveal subsurface structure of the Fukui Plain, central Japan. We located two E-W survey lines; 6 km-long Omori-Harue and 250 m-long Maruoka High School lines in the eastern part of the plain. The station intervals of the lines are 50 and 25 m respectively and the locations of the stations were observed by employing the Differential Global Positioning System (DGPS).
Bouguer gravity anomalies were calculated from the gravity observations, with an assumption of the Bouguer density of 2.3 g/cm3. Bouguer gravity anomalies of the both lines decrease westward with several minor fluctuations. These fluctuations exist immediately above the vertical displacements of the basement implied by recent seismic reflection surveys by Fukui Prefecture.
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