Transit activities: drilling operations tour aboard the RV/DV Joides Resolution

The JOIDES Resolution is currently enroute to our rendezvous point with the U.S Antarctic Program’s RV/IB Nathaniel B Palmer, the icebreaker that will lead us through the sea ice and into the Ross Sea polynya. We will then proceed to our first drilling site on the continental shelf. Before we arrive on site, our job as scientists is to put together the methods sections of our reports within our individual science teams. Our science teams are made up of scientists from various countries and experience levels. Aside from working on the methods, touring labs, and listening to science talks related to what we expect to see in our shelf and rise sites, we have also been exploring the shipboard facilities including: the gym, computer room, and movie room. The first-timers are also trying to not get too lost in our new home.

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Our current ship track has us crossing both the Antarctic Circle and the dateline at the same time before we rendezvous with RV/IB N.B. Palmer

Yesterday, all scientists took a drilling operations tour of the ship, where we learned about the technology involved in obtaining the sediment sequences we will be recovering. Hard hats and safety glasses are required at all times in these areas, due to the inherent risks involved with drilling operations. We first had a look at the machinery on the drill floor where the bottom hole assemblies are prepared for drilling. The derrick is the tallest feature on the ship (147 ft), and the drawworks within the derrick make it possible for us to lower the drill string (pipe) to the sea floor. Inside the drill string are additional wirelines, which bring the sediment core barrels to and from the sea floor. This is a very noisy area, which is strictly off-limits, except for authorized personnel.

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View of the derrick and drawworks from the drill floor. The drill string is lowered through the middle of the ship (moon pool) to the sea floor, where drilling begins, and the drill string advances ~10 meters at a time

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Drill pipes aft of the rig floor awaiting the beginning of drilling operations

I am on the Physical Properties team with four other scientists from the U.S, South Korea, France, and the U.K. When our sediments first come into the laboratory, my group runs the cores through various instruments that measure the physical properties of the sediment. This includes density, magnetic susceptibility (related to sediment composition), and background radiation which helps in identification of clay minerals. These analyses allow us to establish first order sedimentological changes downcore and help us to make hole-to-hole correlations, when we drill multiple holes at one site. Dr. Amelia Shevenell is on the Sedimentology team, which includes eight scientists from the U.S, Norway, India, Japan, Brazil, and South Korea. The sedimentologists describe the core and make detailed notes about the lithology, color, sediment structures, biogenic components, and mineralogy. We will work in the core lab on 12-hour day and night shifts, and will be very busy once the first core arrives on deck!

Journeying to the Ross Sea, Antarctica aboard the RV/DV Joides Resolution

My Ph.D. advisor (Dr. Amelia Shevenell) and I (Imogen Browne) are part of an international scientific team who will spend the next two months aboard the International Ocean Discovery Program’s (IODP) drilling vessel, the JOIDES Resolution. The JOIDES Resolution is a 470-foot long floating laboratory that recovers marine sediments from around the globe to investigate the evolution of Earth’s climate, tectonic, and biologic systems.

On January 8, 2018, IODP Expedition 374 left the port of Lyttleton, New Zealand and began our transit across the Southern Ocean towards the Ross Sea, Antarctica to investigate how Antarctica’s ice sheets have evolved over the last ~25 million years. Expedition 374 is led by co-chiefs Rob McKay from Victoria University in New Zealand and Laura De Santis from Trieste University in Italy, but is the result of a collective effort of a number of scientists over the past 15 years. Expedition 374 is the second IODP expedition to Antarctica in the last decade and only the ninth expedition to the seas around the southernmost continent in the 50-year history of scientific ocean drilling.

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Expedition 374 co-chiefs Laura De Santis (Italy) and Rob McKay (NZ)

To investigate Antarctica’s ice sheet history, we will analyze marine sediments collected from the shallow continental shelf and deeper continental rise of the Ross Sea. These sediments document past environmental changes immediately adjacent to Antarctica. By examining physical, geochemical, and biological changes in these sediments, we can start to piece together how Antarctica’s ice sheets have evolved through time, in concert with changing oceanic and atmospheric temperatures. This is important because the amount of ice on Antarctica influences global sea levels and may be sensitive to changes in the concentrations of greenhouse gases, such as carbon dioxide, in the atmosphere. Understanding how Antarctic ice sheet evolution both influenced and responded to past climate change is required to predict the future response of the ice sheet and global sea levels to ongoing atmospheric and oceanic warming. Stay tuned to hear more about IODP Expedition 374 and learn more about life aboard the JOIDES Resolution over the next 60 days.

JR in lyttleton

The JOIDES Resolution in port, Lyttleton, New Zealand