IODP Expedition 307:
Modern Carbonate Mounds: Porcupine Drilling

Week 5 Report

PDF file is available for download.

May 29, 2005

Operations

The second week of the transit to the United States has been accomplished in generally mild to moderate conditions. As of 1800 hr on 29 May, the vessel has sailed 3360 nmi since leaving Ponta Delgada at an average speed of 10.7 knots. The total distance since leaving the Site U1317 is 4386 nmi. The average speed for the entire transit is also 10.7 knots. During the voyage from the Azores, the clock has been retarded a total of five hours placing the vessel on Central Daylight Time (CDT). The E.T.A. at the Mobile Pilot station is presently 1200 hr CDT on 30 May.

During the second week of the transit from Ponta Delgada, the drilling crew continued routine inspections and addressed additional long-standing maintenance issues. The replacement of the corroded sections of the 12-inch supporting beams on the mud motors was also completed this period. Weathered steel sections on the port and starboard ladderways connecting the rig floor to the core receiving platform were also removed and replaced during this week.

In preparation for the extensive mud requirements of Expedition 308, all the bulk sepiolite and attapulgite were mixed and sheared in the mud pits. The remaining barite (1086 sacks) in Bulk Tank No.4 was blended into selected mud pits to increase the mud weight. Once the vessel is in Mobil, there will be an extensive resupply of bulk material and the blending of additional mud products into the mud pits.

The vessel continues to operate under a MARSEC Security Level I (lowest).

Technical Support Activities

The technical staff finished up the splitting of cores from Hole U1317C. The chemistry lab marine specialists trained on the ICP. Labs are being cleaned and readied for handover to next Expeditions staff.