Reconstructing paleoclimate and ice-sheet dynamics from continental slope deposits

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The aim of the project is to determine the different sediment types on the eastern Ross Sea continental slope, Antarctica. This will help to understand how the Ross Sea shelf and slope developed over time, and the different processes that operated there. This will allow us to reconstruct how the West Antarctic Ice Sheet and climate changed in the past, for example, how far ice extended from the Antarctic continent, how the ice fluctuated, and when these changes occurred. This is important in order for us to understand how ice may change around Antarctica in the future, and the effects this will have on global sea level. Understanding these changes is of significant global importance because Antarctica is experiencing rapid ice loss. This ice loss has doubled in recent years in places. This is due to changes in ocean and atmospheric circulation, with increased observations of warm water masses on the Antarctic shelf. Ocean warming is understood to be one of the main factors causing rapid ice-sheet retreat and instability, leading to potentially irreversible effects. There have also been changes in deep ocean currents in recent years. These currents have global importance as they transfer cold, salty waters to the deep ocean which eventually feed into global ocean currents. This ultimately affects global climate. Oceanographic measurements over the last three decades show significant changes in temperature, salinity, density and depth of the currents, impacting the supply of dense water to the deep ocean. To understand the record of past processes over millions of years, we will collect sediment samples by drilling up to 1 km beneath the seafloor using the drill ship JOIDES Resolution during the International Ocean Discovery Program (IODP) Expedition 374. The expedition is scheduled for January 2018. The main scientific objective is to identify what processes were operating on the continental slope over millions of years and how these processes were influenced by glacial / climate cycles. We will use a range of sampling techniques including obtaining sediment samples and downhole logging data, collected by lowering specialised logging equipment down the drilled holes in the seafloor. We will identify the different slope processes by analysing the sediment core material. This will help us to understand the occurrence, characteristics, frequency and timing of the different sediment deposits which will shed light on what processes were operating in the region. We will look at how the sediment deposits relate to glacial / climate cycles, based on analysis carried out during IODP Expedition 374. We will combine this with regional geophysical data, including information on the seafloor bathymetry and structure beneath the seafloor, to provide information about the shape of the seafloor surface and sub-surface. This will allow recent processes to be identified from seafloor morphology.