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Priority:
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Alternate
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Position:
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27°56.5189′S, 148°35.3969′W (WGS 84)
(27.9420°S, 148.5899°W)
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Water depth (m)
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4852
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Target drilling depth (mbsf):
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106 m, including 100 into basement
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Approved maximum penetration (mbsf):
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Up to 100 m basement penetration. EPSP requested that TAMU considers the steepness of the slope.
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Previous drilling in area:
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Closest drilling:
• IODP Expedition 310 Site 15, 610 nmi away (drilling of corals on Tahiti Platform)
• DSDP Leg 33 Site 318, 800 nmi away (Tuomotu Ridge volcanics)
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Comments:
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International waters; 230 nmi from Rapa, French Polynesia
Preferred weather window: November–December
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Survey coverage
(track map, seismic profile):
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High-resolution seismics:
• Primary line(s): MCS Line 3 - Shotpoint 5072 (Fig. AF7)
• Crossing line(s): None (Fig. AF8)
• Subbottom profile, 3.5 kHz: Line 3 - JDay 360 at 22:08 GMT
• Detailed bathymetry and site location (swath bathymetry: collected with SIMRAD EM120) (Fig. AF9)
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Sediment cores:
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Two piston cores, two trigger cores, one gravity core, and five cores of an eight-barrel multicore
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Objectives
(see text for complete details):
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• Document the habitats, metabolic activities, genetic composition, and biomass of microbial communities in subseafloor sediments with very low total activity.
• Test how oceanographic factors (such as surface ocean productivity) control variation in sedimentary habitats, activities, and communities from gyre center to gyre margin.
• Quantify the extent to which these sedimentary communities may be supplied with electron donors by water radiolysis, a process independent of the surface photosynthetic world.
• Determine how the basement habitats, potential activities, and communities vary with crust age and hydrologic regime (from ridge crest to abyssal plain).
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Drilling/Coring program:
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• Quadruple APC to basement
• RCB upper 100 m of basement
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Downhole logging program:
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None specified
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Anticipated lithology:
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Homogeneous dark brown to very dark brown clay; manganese nodules recovered from core tops
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