Subsurface structure of the Fukaya fault and its southeastern extension as perceived on seismic reflection profiles

Authors: Kazuo Yamaguchi, Naomi Kano, Takanobu Yokokura, Tsutomu Kiguchi, Toshiyuki Yokota, Akiko Tanaka, Yoshito Nakashima and Toshiki Ohtaki

Index Map

Abstract: Several seismic reflection profiles obtained in the northwest Kanto Plain show that the Fukaya active fault certainly continues southeastward in the subsurface from Mikajiri to Kumagaya Bridge across the Ara River. The fault possibly extends further southeastward to the vicinity of the Yoshimi Hills. The SW-dipping fault plane of the Fukaya fault is inferred to be high angle at shallow part and low angle at deep part. The Konan and Kushibiki faults are interpreted as secondary faults of the Fukaya fault, and their fault planes correspond to the NE-dipping reflectors.

Fig.1.Location map of seismic survey lines.
Fig 2. Seismic depth section of line S1.
Fig 3. Seismic depth section of line S2.
Fig.4. Preliminary seismic depth section of line S3.