IODP Expedition 391
Walvis Ridge Hotspot
Daily Science Report for 4 February 2022
Location: Underway to Cape Town, South Africa
Science Update: The vessel completed 220 nmi, and a total of 906 nmi, of the 971 nmi voyage to Cape Town at an average speed of 9.2 kt. The estimated time of arrival is 0730 h on 5 February.
We backed up the database and cleaned the laboratories. Scientists completed all remaining science reports and held a final science meeting to review postexpedition activities.
Daily Science Report for 3 February 2022
Location: Underway to Cape Town, South Africa
Science Update: The vessel completed 271 nmi, and a total of 686 nmi, of the 971 nmi voyage to Cape Town at an average speed of 11.3 kt. The estimated time of arrival is 0730 h on 5 February.
Scientists continued to collect, analyze, and write up data from Hole U1578A. They submitted the first draft of their Site U1578 reports. The laboratory groups presented their Site U1578 results at a science summary meeting.
Daily Science Report for 2 February 2022
Location: Underway to Cape Town, South Africa
Science Update: The vessel completed 271 nmi, and a total of 415 nmi, of the 971 nmi voyage to Cape Town at an average speed of 11.3 kt. The estimated time of arrival is 0730 h on 5 February.
Scientists continued to collect, analyze, and write up data from Hole U1578A.
Daily Science Report for 1 February 2022
Location:
- Hole U1578A (32°19.6836′S, 0°38.5876′W; water depth 3793.8 mbsl; proposed Site CT-05A)
- Underway to Cape Town, South Africa
Science Update: We began pulling the drill string out of Hole U1578A with the top drive installed. When the bit reached 425.9 mbsf, we flushed the drilling service lines (such as mud pumps) with fresh water. At 0045 h, the knobby drilling joints were removed and the top drive was set back. We then continued pulling the drill string out of the hole and the bit cleared the seafloor at 0200 h. When the drill string had been raised to a water depth of 1488.7 m at 0530 h, a repair of a detached wire on the piperacker skate was implemented. After raising the drill pipe to 170 mbsl by 0830 h, we started pulling the RCB BHA to the surface and laid out the drill collars to the drill collar rack. The bit arrived at the rig floor at 1040 h. The rig floor was secured at 1100 h, ending Site U1578. The thrusters were raised and the vessel was switched from DP to cruise mode. We then secured the ship for transit and began our sea passage back to Cape Town at 1130 h, completing 144 nmi of the 971 nmi voyage by the end of the day. The estimated time of arrival is 0730 h on 5 February.
Scientists continued to collect, analyze, and write up data from Hole U1578A.