HR: 10:35h
AN: OS42A-02    [Abstracts]
TI: Cabled Observatory Recorded a M8 earthquake -Revealed phenomena and Necessity to future ocean observatories-
AU: * Mikada, H
EM: mikada@gakushikai.jp
AF: JAMSTEC/Marine Technology Center, 2-15 Natsushima, Yokosuka-shi, 2370061 Japan
AU: Asakawa, K
EM: asakawa@jamstec.go.jp
AF: JAMSTEC/Marine Technology Center, 2-15 Natsushima, Yokosuka-shi, 2370061 Japan
AU: Mitsuzawa, K
EM: mitsuzawak@jamstec.go.jp
AF: JAMSTEC/Marine Technology Center, 2-15 Natsushima, Yokosuka-shi, 2370061 Japan
AU: Shirasaki, Y
EM: yu-shirasaki@k8.dion.ne.jp
AF: Marine Ecotech, Minami-Ohtani, Machida-shi, 1940031 Japan
AB: Scientific results started appearing in the literature using realtime and continuous time series of data obtained on the seafloor for seismic and micro-tsunamic observations. JAMSTEC has developed three out of a total of seven cabled observatories in the Japanese water. The installed observatories are all operating to aid earthquake studies for disaster mitigation at the future potential hazards which take place at plate boundaries surrounding the Japanese islands. Along with earthquake activity monitoring purposes, it has become clear that there are potentially and scientifically meaningful outcome from such observations. We summarize the latest scientific results from monitored data produced by our cabled observatories and, then, to demonstrate advantages of such underwater seismic and tsunamic stations. We also have experienced the latest M8 plate boundary earthquake in September 2003. The cabled observatory has proven the effectiveness of such observation system in the monitoring of earthquakes in the ocean. Discussions finally make it clear that it is necessary to deploy such observatories and to enhance the resolution or signal-to-noise ratio of observations on top of the existing technology of cabled observatories. Especially, much closer access should be tried to seismogenic zones to monitor deep processes or to detect any precursory of plate boundary megathrust earthquakes. It is obvious that newly deployed monitoring systems have revealed meaningful phenomena which have been invisible due to lack of observations in the offshore. Technical and theoretical developments for offshore earthquake minitoring and any related natural events must be well considered.
DE: 7223 Seismic hazard assessment and prediction
DE: 7294 Instruments and techniques
DE: 7209 Earthquake dynamics and mechanics
DE: 4294 Instruments and techniques
DE: 4564 Tsunamis and storm surges
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting