Findings
NanTroSEIZE Logo
  • Science Party

Expedition result
CDEX plans to implement IODP Expedition 358: NanTroSEIZE Plate Boundary Riser 4, beginning on 7 October 2018. The main expedition goal is to deepen riser hole C0002F/N/P from 3000 mbsf to the primary megathrust fault target at ~5200 mbsf, using logging-while-drilling (LWD), downhole measurements, and drill cuttings analysis extensively, in addition to limited coring intervals. This expedition will be the culmination of 10 years of IODP NanTroSEIZE deep drilling efforts to reach the plate interface fault system at seismogenic / slow slip depths.

IODP Site C0002 is the deep centerpiece of the NanTroSEIZE Project, intended to access the plate interface fault system at a location where it is believed to be capable of seismogenic locking and slip, and to have slipped coseismically in the 1944 Tonankai earthquake. This drilling target also is in close proximity to the location where a cluster of very low frequency (VLF) seismic events and the first tectonic tremor recorded in any accretionary prism setting has been found, all suggesting fault processes related to the up-dip limit of megathrust seismogenic mechanics are active here.