Unravelling the Holocene history of the Last Ice Area in the Arctic Ocean

Rapid retreat of Arctic sea-ice is one of the most prominent expressions of modern climate change, yet our knowledge of natural sea-ice variability on millennial time scales is limited.

To build a longer-term perspective on Arctic sea-ice dynamics, knowledge on past sea-ice and ocean conditions is required.

Sea-ice conditions during the Holocene (the past 11.600-years) remain poorly constrained; the state of Arctic sea-ice extent during the Holocene Thermal Maximum, Earth’s last relatively warm period when global temperatures reached 0.7°C above Preindustrial levels, is controversial.

This project aims to resolve the status of Arctic sea-ice conditions during the Holocene using Arctic Ocean sediment archives.

To do this, I will exploit sediment cores recovered from recent and upcoming expeditions to a notoriously inaccessible region of the Arctic Ocean known as the ’Last Ice Area’. This is a key region because it represents the last refuge for sea ice under warming conditions.

A multi-proxy approach will be applied using benthic/planktic foraminifera and dinoflagellates – microfossils diagnostic of ocean and sea-ice conditions at the time of deposition. Complementary sea-ice reconstructions will be based on new (%C37:4) and established (IP25) lipid biomarkers.

The produced knowledge will improve our understanding of natural sea-ice variability and its relation to warm ocean currents, which is highly relevant for gaining a better understanding of future climate change.