HR: 09:00h
AN: S41D-05    [Abstracts]
TI: NanTroSEIZE: The Nankai Trough Seismogenic Zone Drilling Project
AU: * Tobin, H
EM: tobin@nmt.edu
AF: Earth and Env. Sci. Dept., New Mexico Tech, Socorro, NM 87801 United States
AU: Kinoshita, M
EM: masa@jamstec.go.jp
AF: Deep Sea Research Program, JAMSTEC, Yokosuka, 237-0061 Japan
AU: Kimura, G
EM: gaku@eps.s.u-tokyo.ac.jp
AF: Earth and Planetary Sci. Dept., University of Tokyo, Tokyo, 113-0033 Japan
AU: Underwood, M
EM: UnderwoodM@missouri.edu
AF: Dept. of Geol. Sci., Un. of Missouri, Columbia, MO 65211 United States
AU: Ashi, J
EM: ashi@ori.u-tokyo.ac.jp
AF: ORI, Un. of Tokyo, Tokyo, 113-0033 Japan
AU: Saffer, D
EM: dsaffer@uwyo.edu
AF: Dept. of Geol. and Geop., Un. of Wyoming, Laramie, WY 82071 United States
AU: Brown, K
EM: kmbrown@ucsd.edu
AF: Scripps Inst. Oceanog., UCSD, La Jolla, CA 92093
AU: Henry, P
EM: henry@cdf.u-3mrs.fr
AF: CNRS, College de France, Aix-en-Provence, 13545 France
AU: Suyehiro, K
EM: suyehiro@jamstec.go.jp
AF: Deep Sea Research Program, JAMSTEC, Yokosuka, 237-0061 Japan
AB: The Integrated Ocean Drilling Program has recently accepted NanTroSEIZE as a multi-year, multi-phase drilling and observatory installation project of unprecedented scope. NanTroSEIZE is an integrated program of geophysical studies, drilling, and instrumentation designed to investigate the aseismic to seismic transition of the megathrust system and the processes of earthquake propagation and tsunami generation at the Nankai Trough subduction zone. The fundamental goal is the creation of a distributed observatory spanning the up-dip limit of seismogenic and tsunamigenic behavior. This will involve sampling and instrumenting key elements of the active plate boundary fault system at several locations off the Kii Peninsula, Japan. Here, the plate interface and active mega-splay faults are accessible to drilling within the region of coseismic rupture and tsunami source in the 1944 Tonankai M8 great earthquake. The ultimate objective is to access and instrument the Nankai plate interface to advance our knowledge of fundamental aseismic and seismic faulting processes and controls on the transition between them. NanTroSEIZE will test models for the frictional behavior of fault rocks across the aseismic - seismogenic transition, the composition of faults and fluids and associated pore pressure and state of stress, partitioning of strain spatially between basal interface and splays, temporally between coseismic and interseismic periods, and between infraseismic and aseismic events vs. seismic events. Long-term borehole observations potentially will ultimately test whether interseismic variations or detectable precursory phenomena exist prior to great subduction earthquakes. Drilling and instrumentation will span the zone from input of sediment, crust, and fluids at the trench through the mega-splay and decollement fault systems at up to 6 km below the sea floor. Eight distinct drilling sites are targeted, with a comprehensive program of coring, geophysical logging, downhole geophysical and hydrological experiments. Opportunities exist for many new researchers to become involved in the NanTroSEIZE effort.
UR: http://ees.nmt.edu/nantroseize
DE: 7230 Seismicity and seismotectonics
DE: 8010 Fractures and faults
DE: 8150 Plate boundary--general (3040)
DE: 8159 Rheology--crust and lithosphere
DE: 7209 Earthquake dynamics and mechanics
SC: Seismology [S]
MN: 2004 AGU Fall Meeting