著者

2003年九州日奈久断層域構造探査グループ

出版者

東京大学地震研究所

雑誌

地震研究所彙報 (ISSN:00408972)

巻号頁・発行日

vol.83, no.1, pp.103-130, 2008

---

The Hinagu fault system, Kyushu, Japan, is located in the westernmost part of the Beppu-Shimabara graben. This fault system is characterized by a quite high seismic activity and estimated to have a higher seismic risk among active faults in Kyushu Island. In 2003, we conducted an extensive seismic expedition in and around the Hinagu fault area. This expedition involves seismic refraction/wide-angle reflection experiment using dynamite shots and seismic array observation both for the active and passive seismic sources. For the refraction/wide-angle reflection study, two profile lines of 56.4 and 32.1km lengths were set in EW and NNE-SSW directions, respectively, on which 7 dynamite shots of 100-200kg charge and 359 recorders were deployed. The array observations, which were designed for high-resolution imaging of crustal scatterors and reflectors, were undertaken at 5 sites in the fault region. This paper presents the outline of this seismic expedition and fundamental data obtained.