Site summaries

Site JFAST-3

Priority: Primary
Position: ~37°56.3022′N, 143°54.8405′E  
Water depth (m): 6910
Target drilling depth (mbsf): ~1000
Survey coverage (track map; seismic profile): Lines HD33B and HS41B; Figure F1B
Objective: Determine stress state on the fault Characterize large earthquakes in the fault zone
Drilling program: Hole A: LWD to ~950 mbsf; install casing/​temperature monitoring string to ~950 mbsf
Hole B: RCB to ~950 mbsf; install casing/​temperature and pressure monitoring string to ~850 mbsf
Logging/downhole measurements program: Hole A: LWD⁄MWD to ~950 mbsf
LWD: resistivity, electrical imaging, gamma ray
MWD: annular pressure while drilling, temperature
Nature of rock anticipated: Highly disrupted hemipelagic deposits. A chert layer is anticipated within a 100 m zone above TD.