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doi:10.2204/iodp.proc.325.104.2011

Hole M0045A

Operations

Site 8, Hole M0045A

The Greatship Maya was on station over Hole M0045A in 4 min, with the downpipe camera still deployed (Table T1). A precoring camera survey was conducted, and the camera was recovered to deck by 1910 h. The seabed was tagged at 1945 h, and coring commenced. However, after initially appearing to core, the drill string then dropped 3 m abruptly. It was believed that the drill string was skipping down the side of the target coral pinnacle, so the vessel was moved 2 m closer to Hole M0044A before trying another run. The seabed was again tagged, and the drill string appeared to be compensating at 2115 h. However, the first and second standard rotary corer runs again appeared to skip down the side of the pinnacle, with the drill string dropping quickly and with no apparent force. The last 70 cm of the third run appeared to drill very hard material. However, while recovering the barrel, the drill string fell abruptly by 8 m—it was thought that the string had reentered Hole M0044A. If this was so, the drill string should have stopped at the total depth for Hole M0044A of 11 mbsf, but it continued to freefall until 14.6 “mbsf.” As it was not clear whether the API string had actually penetrated the target pinnacle or was skipping down its side, the decision was made to abandon Hole M0045A and move the vessel. Two API pipes were tripped by 0025 h on 11 March, and the Greatship Maya was moved 3 m under dynamic positioning to the opposite side of Hole M0044A.

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