[S-SS26_30PO1] Crustal Structure

[SSS26-P11] Seismic Reflection Surver around the Mouth of Fuji River

*Shinobu ITO¹, Kazuo YAMAGUCHI¹, Ryohei IRITANI¹, Yoshiaki YAMANAKA², Shun'ichiro ITO², Kazunori MURATA² (1.GSJ, AIST, 2.Suncoh Consultants Co., Ltd)

Keywords:seismic reflection survey, Fuji River

We conducted seismic reflection survey around the mouth of Fuji River in February 2014. Fujikawa-kako fault zone is identified around this area. Shimokawa et. al. (1996) conducted seismic reflection survey in this area, and identified the Iriyamase fault. Shizuoka Pref. (1996) also identified the Nakayama fault. Our purpose of the survey is that we understand structure around both the Iriyamase and the Nakayama fault in more detail than the previous studies. There are two seismic survey lines. A survey line FJK1 is located from the mouth of Fuji river toward Mukaida river along the coastline, and the length of the line is about 3.5km. A survey line FJK2 is located on the right bank of Fuji river and at about 2km north from the coastline, and cross over the Kambara Jishinyama. The length of FJK2 is a little bit longer than 1km. We used IVI Y2400 as seismic source. Sweep frequency for FJK1 and FJK2 is 10 to 100Hz and 10 to 120Hz, respectively. Sweep length is 12s, and record length is 16s for both lines. We used SG-10 (10Hz of natural frequency) and DSS-12 that is a distributed seismic data acquisition system. Temporal spread length of FJK1 is about 1km. We fixed the spread of FJK2. Geophones are set at intervals of 5 meters for both lines. Some events can be deduced as reflected waves in some samples of shot records for FJK1. However, we are afraid that they are produced by a bank. Soon, we are going to show detailed results.