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Priority:
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Primary
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Position:
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26°03.0953′S, 156°53.6566′W (WGS 84)
(26.0516°S, 156.8943°W)
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Water depth (m)
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5127
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Target drilling depth (mbsf):
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17 m
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Approved maximum penetration (mbsf):
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Until basement is encountered
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Previous drilling in area:
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DSDP Leg 91 Site 596, 500 nmi away
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Comments:
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International waters; 255 nmi from Mangaia Island, Cook Islands
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 1 - Shotpoint 2911 (Fig. AF4)
• Crossing line(s): MCS Line 3 - Shotpoint 3608 (Fig. AF5)
• Subbottom profile, 3.5 kHz: Line 1 - JDay 358 at 02:20 GMT
• Detailed bathymetry and site location (swath bathymetry: collected with SIMRAD EM120) (Fig. AF6)
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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 taken at site location
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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 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.
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Drilling/Coring program:
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• Quadruple APC to basement
• Temperature measurements: APCT-3
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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 clay; manganese nodules recovered from core tops
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