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doi:10.2204/iodp.proc.324.103.2010

Operations

Times in this chapter are given in local ship time. During transit to Site U1346, shipboard clocks were advanced 1 h, resetting local ship time to Sydney Standard Time (Universal Time Coordinated + 10). No further adjustments to the clock were made during the expedition.

Yokohama port call

Expedition 324 started on 4 September 2009 at the port of Yokohama, Japan, with the changing and crossover of Overseas Drilling Limited and Integrated Ocean Drilling Program personnel. Expedition 324 scientists boarded the ship on 5 September. In addition to the routine resupply of expendables and the offloading of Expedition 323 cores and returning freight, some items of note were the loading of 1800 MT of marine gas oil, overhaul of the passive heave compensator, and service visits by Novenco (air conditioning), RigNet (Very Small Aperture Terminal [VSAT]), and Hose-McCann (ship phone/intercom/alarm system) field engineers. This port call was also noteworthy for the extensive number of visitors that were treated to a tour of the vessel including visitors of the National Museum of Nature and Science in Tokyo, members of the Japanese scientific community, and U.S. embassy personnel. A press conference for Japanese and international media was held on 5 September.

During this ~5 day port call, we were not able to send or receive e-mail or use the ship's phone system because of local electromagnetic interference, which prevented VSAT operation. Although some maintenance was possible on the aft antenna, the RigNet engineer was unable to perform a systems check and calibration to the VSAT system because of the interference.

Once the last line was released at 0950 h on 9 September, the vessel was under way to the pilot station. The RigNet engineer stayed aboard and attempted last-minute adjustments while working with rig-based technicians. The pilot and RigNet representative disembarked at the pilot station at ~1130 h. A short time after this, VSAT operation was restored and remained until the first course change. At this time, the signal was lost and in spite of the best efforts of onboard technicians communicating with the RigNet engineer in the hotel using the Inmarsat GMDSS satellite phone, the VSAT system could not be restored to normal working order. A decision was made to reverse course, return to a convenient rendezvous point close to the head of Boso Peninsula, and bring the RigNet engineer back to work on the system.

The RigNet engineer was welcomed aboard shortly before 0600 h on 10 September and remained for nearly 2 h restoring the VSAT to operation. Once he departed at 0740 h, the vessel began its voyage to Site U1346.

Transit to Shatsky Rise and Site U1346 (Shirshov Massif)

The R/V JOIDES Resolution came to position at Site U1346 at 0930 h on 14 September 2009. The 1129 nmi voyage from Yokohama, Japan, was accomplished at an average speed of 11.8 kt and was without incident. The four-stand RCB drilling assembly was made up and deployed as the drilling crew performed the routine first site measuring and internal clearance check of each tubular.

After the driller tagged seafloor at 3630.0 m drilling depth below rig floor (Table T1; 2.6 m deeper than the corrected precision depth recorder depth), Hole U1346A was spudded with a center bit in place at 0140 h on 15 September. The hole was advanced to 71.0 m drilling depth below seafloor (DSF) at an average rate of penetration (ROP) of 20.8 m/h. During the course of drilling this interval, hard layers were encountered at 60.0, 67.0, and 71.0 m DSF and were assumed to be chert. The worn center bit was retrieved by coring line and replaced with a wash barrel. The hole was advanced by drilling ahead from 71.0 to 100.5 m DSF. The 29.5 m advance through chert layers was accomplished at an average ROP of 8.9 m/h. The wash barrel contained 0.21 m of chert including one nicely cored single-piece sample that was ~15 cm in length.

Rotary coring was initiated at 100.5 m DSF and deepened the hole to a total depth of 191.8 m DSF by 0915 h on 18 September. Basaltic basement was contacted at 139.2 m DSF. Total penetration into basement was 52.6 m (Fig. F3). The average ROP for the cored interval was 2.0 m/h with an average recovery of 28%. The average ROP for basement coring was 1.3 m/h with an average recovery of 38.7%. Because of the slow penetration rate combined with the successful recovery of material suitable to address most of the objectives for this site, it was decided to end coring at this depth and prepare the hole for logging operations. An additional factor in the decision to cease coring operations at this site was the approach of Typhoon Choi-Wan.

Following a wiper trip and displacement of the hole with 38.5 bbl of mud, the triple combination (triple combo) tool string was deployed on 18 September. The tools were able to log the open hole to within 10 m of the bottom of the bore. The poor condition of the hole and significant heave did not warrant deployment of the Formation MicroScanner (FMS)-sonic tool suite. Logging tools were secured by 0845 h on 19 September.

The drilling assembly was pulled free of the seafloor and fully recovered. After the beacon was recovered from 20 ft seas, the thrusters were retracted and the vessel departed for the 370 nmi voyage to Site U1347 (proposed Site SRSH-3B) at 1800 h on 19 September. Because of the proximity of Sites U1348 and U1349 (proposed Sites SRCH-6 and SRSH-5, respectively) to Typhoon Choi-Wan's projected track, it was decided to proceed directly to the more southerly and higher priority site.

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