Next Section | Table of Contents


Site: HR1a

Priority: Primary

Position: 44.586159°N, 125.119213°W

Water Depth: 890 m

Sediment Thickness: ~7 km

Target Drilling Depth: 350 mbsf

Approved Maximum Penetration: 350 mbsf

Seismic Coverage: TTN112 3-D high-resolution seismic survey

Objectives: To determine the source and distribution of hydrate in the steeply dipping, stratified sediments on the eastern flank of Hydrate Ridge; the nature of the B/B' reflections that underlie the BSR; and the composition, structure and gas content of the seismically incoherent unit underlying the deformed and uplifted sediments on the east flank of Hydrate Ridge. To sample subsurface biosphere and determine impact on methanogenesis and oxidation of methane.

Drilling Program: APC to refusal, XCB to refusal, RCB as necessary to reach target depth. Three holes. Frequent use of PCS and/or HYACE.

Logging and Downhole Program: LWD; triple combo, APC-temperature, DVTP, APC methane tools; VSP and walkaway VSP.

Nature of Rock Anticipated: Interlayered silts and clays, some authigenic carbonates possible, highly deformed accretionary complex sediments.

Next Section | Table of Contents