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IODP Expedition 374

Ross Sea West Antarctic Ice Sheet History


Daily Science Report for 17 January 2018

Location: Hole U1521A (75°41.0351′S, 179°40.3108′W; water depth 566 m)

Science Update: We continued to RCB core in Hole U1521A from Core 3R to 31R (17.0–294.9 mbsf). Core recovery was mixed in the upper 150 mbsf, varying from less than 5% in several cores to as high as 89%. Recovery improved markedly below 150 mbsf to the bottom of the cored section. Overall recovery for the day was better than 50%. The age at the bottom of the recovered section is middle Miocene based on diatoms. Cores 1R through 13R were split and described. The uppermost sediment consists of diatom-rich mud to diatom-bearing sandy mud with clasts. Below this the sediment consists of alternating intervals of dark gray muddy diamict and diatom-rich mud to diatom ooze. The diamicts include varying numbers of clasts. A few shell fragments were found in diatom-bearing mud near the base of the described interval.


Daily Science Report for 16 January 2018

Location:
• Underway to Site U1521 (proposed Site EBOCS-01D)
• Hole U1521A (75°41.0351′S, 179°40.3108′W; water depth 566 m)

Science Update: We arrived at Site U1521 and switched to dynamic positioning at 0938 h. The drilling crew made up and spaced out the outer core barrel, picked up the drill collars, made up the bottom-hole assembly, and then started tripping pipe toward the seafloor. During the trip, the pipe was drifted (checked to ensure that the interior was clear) and strapped (measured). After the drill bit reached 520.11 m below rig floor (mbrf), the drilling crew picked up the top drive and pumped a clean out “pig” to ensure that the interior of the drill string was free of rust and other debris. After dropping a core barrel, we started Hole U1521A at 1845 h with the rotary core barrel coring system. The driller tagged the seafloor at 573 mbrf (566 m below sea level), then slowly advanced the drill bit without rotation to collect a “push core.” After hitting a hard layer, the driller began rotating the drill string to finish cutting the first core. By the end of the day we had collected Cores U1521A-1R and 2R to a depth of 17.0 m below seafloor with average recovery of 35%.

While preparing for the beginning of coring operations later in the day, the scientists received SampleMaster training from the Curator. The Co-Chief scientists introduced the scientific objectives for Site U1521. A scientist also presented initial results from the site survey cruise conducted in this region last year. The Co-Chiefs, Operations Superintendent, Laboratory Officer, Assistant Laboratory Officer, Captain, Ice Observer, Schlumberger Engineer, and Offshore Installation Manager met to discuss drilling and logging operations for the expedition. After initiation of coring operations, the geochemists and paleontologists began processing and analyzing samples. The age of Core U1521A-2R is upper Pliocene based on diatoms and radiolarians.


Daily Science Report for 15 January 2018

Location:
• Underway to Site U1521 (proposed Site EBOCS-01D) 0.5 nmi behind the RVIB Nathaniel B. Palmer
• Underway to Site U1521 (proposed Site EBOCS-01D) without escort

Science Update: We continued to follow the RVIB Nathaniel B. Palmer, reaching the northern edge of the sea ice at ~0630 h. We cleared the southern edge of the sea ice at 1220 h, and the Palmer was released at 1300 h. Our ETA at Site U1521 is 1000 h on 16 January. The scientists continued examining legacy Antarctic cores throughout the day. The sedimentologists and paleontologists on the day shift received training on the desktop scanning electron microscope (SEM). The Co-Chief Scientists, Curator, Assistant Laboratory Officer, and Staff Scientist met with the geochemists and microbiologists conducting catwalk sampling to finalize the site-specific plan. The science party received an overview of the lithological framework of the region based on previous drilling and outcrop-based sampling. The Co-Chiefs also gave an overview of the expedition objectives for the crew and technical staff.


Daily Science Report for 14 January 2018

Location:
• In transit to rendezvous with the RVIB Nathaniel B. Palmer for escort into the Ross Sea polynya
• Underway to Site U1521 (proposed Site EBOCS-01D) 0.5 nmi behind the RVIB Nathaniel B. Palmer

Science Update: The scientists continued practicing laboratory methods and describing legacy cores. The sedimentologists and paleontologists on night shift received training on the desktop scanning electron microscope (SEM). We celebrated crossing the Antarctic Circle with cupcakes and screening of a 20 min film showing footage from past Antarctic scientific expeditions that was originally debuted at the Past Antarctic Ice Sheet (PAIS) science conference in September 2017. We began our rendezvous with the RVIB Nathaniel B. Palmer at 1930 h and commenced following 0.5 nmi behind at a speed of 10.0 kt to transit through the sea ice. The ETA for the northern edge of the sea ice is 0600 h on 15 January.


Daily Science Report for 13 January 2018

Location: In transit to rendezvous with the RVIB Nathaniel B. Palmer for escort into the Ross Sea polynya (updated ETA 2100 h on 14 January 2018)

Science Update: The scientists continued moving onto shifts. The sedimentologists began to practice visual core description and preparation and description of smear slides using legacy cores from previous Antarctic expeditions, including Deep Sea Drilling Project (DSDP) Site 270, Ocean Drilling Program (ODP) Site 1165, and Integrated Ocean Drilling Program Site U1361. They were also introduced to the Vanta handheld X-ray fluorescence (XRF) third-party tool and they used it to measure the legacy cores. The other laboratory groups also continued to practice laboratory methods. We saw our first iceberg of the expedition in midafternoon, and are scheduled to cross the Antarctic Circle at 0400 h on Sunday 14 January.


Daily Science Report for 12 January 2018

Location: In transit to rendezvous with the RVIB Nathaniel B. Palmer for escort into the Ross Sea polynya (ETA 0600 h on 15 January 2018)

Science Update: The scientists continued to work in laboratory groups throughout the day. In the morning, designated Sedimentologists and Geochemists met with the X-ray technician to discuss procedures and setup for the handheld X-ray fluorescence (XRF) tool. Three scientists presented talks on drift sedimentation and correlation of core data with seismic stratigraphy in the North Atlantic, as well as seismic stratigraphic data and facies analysis of piston cores collected on a recent cruise to the Ross Sea. In the afternoon, the Operations Superintendent gave a talk to the science party explaining coring operations on the JOIDES Resolution, after which the Staff Scientist introduced the science party to IODP depth scales. Each laboratory group submitted a first draft of their Methods section. Scientists also began to move onto shifts at the end of the day.


Daily Science Report for 11 January 2018

Location: In transit to rendezvous with the RVIB Nathaniel B. Palmer for escort into the Ross Sea polynya (ETA 0600 h on 15 January 2018)

Science Update: The Co-Chief Scientists and Staff Scientist met with the Operations Superintendent to discuss the expedition operations plan. We decided to rearrange the order of the first three sites to start with proposed Site EBOCS-01D, followed by proposed Sites EBOCS-03C and EBOCS-04B, to minimize transit and maximize operational time. After coring at Site RSCR-02B, we will then occupy Site RSCR-14A (instead of Site RSCR-11A) and Site RSCR-19A (instead of Site EBOCS-02B). Site RSCR-14A should provide a more complete record than Site RSCR-11A, and we added Site RSCR-19A to the primary plan based on the recommendation of the IODP Science Evaluation Panel. The scientists continued to work on laboratory procedures and methods. The Imaging Specialist met with the core describers to set up the microscope for smear slide observation. In the afternoon, the Curator introduced the scientists to shipboard sampling and residues, after which we discussed shipboard measurements and sampling resolution.


Daily Science Report for 10 January 2018

Location: In transit to rendezvous with the RVIB Nathaniel B. Palmer for escort into the Ross Sea polynya

Science Update: The scientists continued to work on laboratory procedures and write methods sections. The Laboratory Officer gave a presentation and showed a video on hydrofluoric acid (HF) safety to the scientists working in the Geochemistry Laboratory where HF will be used to process samples for palynomorphs. The Operations Superintendent gave three ship tours that included the rig floor, core tech shop, and mud rooms. The scheduled rendezvous with the RVIB Nathaniel B. Palmer is set for 0600 h on 15 January.


Daily Science Report for 9 January 2018

Location: In transit to rendezvous with the RVIB Nathaniel B. Palmer for escort into the Ross Sea polynya

Science Update: The Staff Scientist gave a short presentation on best practices for posting to social media. The Education and Outreach officers then introduced the science party to their plans for the expedition and explained how the scientists could participate, including blogging and posting to social media. After lunch, four scientists presented their research from IODP Expedition 318 (Wilkes Land Glacial History). The scientists also continued to work on laboratory methods and protocol. The first abandon ship and fire drill was held in the morning.


Daily Science Report for 8 January 2018

Location:
• Berth No. 7, Lyttelton, New Zealand
• In transit to rendezvous with the RVIB Nathaniel B. Palmer for escort into the Ross Sea polynya

Science Update: New Zealand customs and immigration boarded the vessel in the morning to clear it for departure. Following this, the Staff Scientist gave a core flow laboratory tour to the Paleomagnetists, Physical Property Specialists, Geochemists, and Education and Outreach team. At the same time, the Sedimentologists and Paleontologists continued to work on methods in their laboratory groups. The Imaging Specialist also worked with the Paleontologists to set up their microscopes. The scientists were given from ~1030 to 1400 h to go into town to buy last minute supplies. In the afternoon, the Staff Scientist and Publications Specialist introduced procedures and best practices for writing shipboard reports. Following this, the Staff Scientist gave a core flow laboratory tour to the Sedimentologists and Paleontologists while the other scientists continued working on methods. Port call activities concluded with an inspection for the Polar Code certificate and discharge of remaining items. The pilot boarded the vessel at 1552 h, and the vessel departed Lyttelton with the last line away at 1624 h. Sea passage to the rendezvous with the RVIB Nathaniel B. Palmer began at 1648 h when the pilot departed the vessel.


Daily Science Report for 7 January 2018

Location:
• Oil Berth, Lyttelton, New Zealand
• Berth No. 7, Lyttelton, New Zealand

Science Update: The Co-Chief Scientists introduced the scientific objectives of the Ross Sea West Antarctic Ice Sheet History expedition to start the day. We then conducted a research planning meeting. Each scientist presented a brief (~2–3 min) summary of his or her proposed postcruise research objectives and sampling plan to meet those objectives. After lunch, the science party divided into laboratory groups, with the sedimentologists and paleontologists receiving an introduction to DESClogik. The physical property specialists, paleomagnetists, and geochemists each met with the IODP JRSO technicians in their respective laboratories for an introduction to laboratory equipment and methods. We ended the day with Polar Code cold weather training for all scientists and IODP JRSO technical staff who had not previously completed the training. Port call activities included completing fueling operations, shifting the vessel back to Berth No. 7, and loading of fresh food for the expedition. Departure is planned for 1800 h on 8 January.


Daily Science Report for 6 January 2018

Location:
• Berth No. 7, Lyttelton, New Zealand
• Oil Berth, Lyttelton, New Zealand

Science Update: We began the day with a meet and greet for the scientists and IODP JRSO technical staff, followed by a presentation by the Staff Scientist that explained what we would be doing during the expedition. The Marine Computer Specialists gave the scientists an introduction to I.T. and computing aboard the JOIDES Resolution, then the scientists connected their computers to the shipboard network. After lunch, the Captain welcomed the scientists to the vessel and gave an introduction to policies and procedures aboard the vessel. The Ship’s Doctor then conducted a shipboard safety meeting. The Staff Scientist concluded the day with an introduction to the shipboard server structure. Port call activities included loading of bulk, freight, and frozen food, as well as discharging sea freight and remaining Schlumberger logging-while-drilling tools. In the afternoon the vessel shifted to the Oil Berth to begin taking on fuel for the expedition.


Daily Science Report for 5 January 2018

Location: Berth No. 7, Lyttelton, New Zealand

Science Update: The ship’s crew completed crew change and crossover at ~0730 h. The Expedition 374 science party boarded the vessel at 0930 h and were shown to their berths. After a short introductory meeting, the scientists were given time to settle in and have lunch. At 1300 h, the science party convened for presentations about life aboard the vessel. The science party then divided into three groups for a ship safety tour. Other port call activities included loading of freight for the expedition. We also conducted several tours with faculty, staff, and students from local universities.


Daily Science Report for 4 January 2018

Location: Berth No. 7, Lyttelton, New Zealand

Science Update: The Ross Sea West Antarctic Ice Sheet History Expedition 374 began with the first line ashore at 0706 h. Oncoming IODP JRSO technical staff and the Co-Chief Scientists boarded the vessel at 1000 h and completed crossover with the offgoing staff, who departed the vessel midafternoon. Port call activities included loading of IODP air freight and containers. A press conference was held in the afternoon, with the Expedition 372 Co-Chiefs giving a summary of results from their expedition and the Expedition 374 Co-Chiefs giving an introduction to the expedition scientific objectives. The press conference attendees were then given tours of the vessel. At 1745 h, the vessel was shifted to its current location at Berth No. 7.