HR: 1340h
AN: OS23A-1040    [Abstracts]
TI: Deep-sea floor instability to cause of deep-water cable fault, off East Taiwan
AU: * Soh, W
EM: soh@jamstec.go.jp
AF: Kochi Institute for Core Sample Research, JAMSTEC, B200, Monobe, Nankoku, 783-8502, Japan
AU: Machiyama, H
EM: bucci@jamstec.go.jp
AF: Kochi Institute for Core Sample Research, JAMSTEC, B200, Monobe, Nankoku, 783-8502, Japan
AU: Shiraishi, Y
EM: shirasaki@marine-tech.co,jp
AF: Marine Eco Tech Ltd., 200, Yayoi, Machida, 194-0004, Japan
AU: Kasahara, J
EM: Kasahara@tairiku.co.jp
AF: Tone Geoscience Center, 1-20, Tsukiyoshi, Mizunami, 509-6100, Japan
AB: In 2002 to 2003 years, many deep-water cable faults were taken place in the sites deeper than 4,700 m of water depth, off east Taiwan to the Okinawa Trench. Many commercial base cables were seriousely brocken in the events. To investgate the cause of the cable fault in the deep water environment we examined the location and timing of the cable faults and compared them with data/records of the bathymetry, sesimic records and precipitation of the coast range of Taiwan. Because the events were most likely to be caused by turbidite flows that run and developed along the submarine channels such as Taitung and Hualien Channels. Velocity of the turbidites reached 10 to 12 m/s on an average in the setting. The turbidtes were not hyperpicnal flow being caused by onland food event but seismoturbidite. The events were taken place just after earthqaukes ranging from 5.0 to 6.0, and the depths of the EQ sources were shallower than 23 km in and around the coast range of Taiwan. What we learn from this case is that the cable fault may be happened if the condition (or rule) is satisfied. If it is true, the cable fault in the deep water environment in the region can be predicted.
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 3070 Submarine landslides
DE: 7221 Paleoseismology (8036)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting