NanTroSEIZE Workshop 2002
Developing a Community Sediment Mode

The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is a multi-disciplinary, integrated study of the SW Japan subduction interface, with proposed deep drilling of the plate boundary fault system as its centerpiece. Great subduction earthquakes are responsible for ~90% of global seismic energy release and are among the most destructive natural hazards. The fundamental goal of the NanTroSEIZE project is to investigate poorly-understood faulting processes at depth.

Geophysical studies, submersible diving, and Ocean Drilling Program (ODP) boreholes have been or are now being carried out as part of this project. The successor to ODP, the Integrated Ocean Drilling Program (IODP), is slated to begin in late 2003. In IODP, the new research drilling ship Chikyu will have the unprecedented ability to access depths of many kilometers below the seafloor to sample rocks and fluids and to emplace long-term instrumentation. The centerpiece of the NanTroSEIZE proposal to IODP is the deep borehole observatory, to be drilled into a region within the rupture zone of the 1944 M8.1 Nankai earthquake.

The NanTroSEIZE workshop was held in Boulder, Colorado on July 21-23, 2002, in order to reach consensus among a broad cross-section of the fault-zone studies community on the key scientific questions and how they should be approached. A document laying out the NanTroSEIZE Science Plan, as well as specific drilling proposals for IODP, is now being prepared by workshop participants and others.