Reconstructing paleoclimate and ice-sheet dynamics from continental slope deposits

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.

Determining the signature of past processes provides huge potential for understanding how ice sheets and ocean circulation changed in the past, for example, when climatic conditions resembled 'worst-case' future climatic scenarios and may provide important clues as to how they may change in the near future; and what effects this may have on ice retreat and sea-level rise. This has inherent global importance for reconstructing ocean circulation and ice-sheet change including seafloor erosion patterns, continental margin and canyon evolution, large-scale slope instability and interpreting sediment core records from the continental slope and rise. The information gained during this project will ultimately improve understanding of the effects of climate and oceanic change on ice-sheet stability / instability, and will improve numerical modelling constraints for determining future ice-sheet and sea-level change.

The results of this study are of significant benefit not only to those working within academia (e.g. internationally within the disciplines of sedimentology, paleoclimate and numerical ice-sheet modelling), but also to those that advise government organisations on future risks, and strategies to mitigate future changes. Modelers at the British Antarctic Survey and the Euro-Mediterranean Center on Climate Change (CMCC) will benefit directly from improvements to ice-sheet modelling constraints. This will lead to greater reliability of ice-sheet reconstructions and sea-level rise predictions, which are of national, international, societal and economic importance. Planners (e.g. DEFRA) tasked with assessing future risks posed by sea-level rise to the UK will also benefit from improved modelling constraints. Policy makers (e.g. the Department of Energy and Climate Change (part of the Department for Business, Energy and Industrial Strategy) and the Intergovernmental Panel on Climate Change) will benefit as this research will support implementation of UK international policy commitments. Environmental groups, such as Friends of the Earth, 350.org and Greenpeace, who are concerned with the impact of climate change on the environment, will benefit from improved understanding of the rate and impacts of future change.

The Public Sector will benefit through internationally important research aiming to mitigate the effects of climate change and sea-level rise. Oceanographic observations show significant changes in water masses in the Ross Sea, with ice loss also doubling in recent years around Antarctica, potentially warning of larger changes to come. There is a clear need to improve understanding of past and present high-latitude processes, the behavior of the West Antarctic Ice Sheet and risks associated with future ice-sheet and sea-level change.

School children will benefit through engagement in research relating to Science Technology Engineering and Math (STEM), in particular challenging perceptions of male-dominated stereotypes that a career in STEM subjects carry. PhD, Masters and Undergraduate Students at Plymouth University will benefit from enhanced curriculum and involvement in leading Antarctic research, including the potential to be involved in research projects relating to this work. Undergraduate and Masters-level students will thus benefit from career development opportunities associated with the project through training, engagement and onward development.