IODP 3 Expedition 507 “Late Cenozoic Glaciers, LAndscapes, Climates, and Ecosystems of the North Sea (GLACE-NS)” Scientific Prospectus

Abstract

Abstract. Intensification of glacial–interglacial cycles at the Pleistocene onset (∼ 2.6 Ma) was a critical transition in Earth's climate history. The increased severity of cold conditions triggered the development of continental-scale ice sheets, which then affected the global climate system through complex ocean–atmosphere–cryosphere linkages. Besides estimates of global ice volume with poor spatio-temporal control, little is known about late Plio-Pleistocene ice sheet fluctuations during the transition from late Pliocene warmth to intensified Pleistocene glaciations, or the apparent change to greater ice volumes during the Middle Pleistocene Transition (∼ 1.2–0.8 Ma). Our inability to reconstruct the extent of ice sheets through these major climate shifts limits our understanding of the causes of long-term climate change and the ways in which ice sheet feedback loops influence environmental change. The North Sea Basin (NSB) contains a ∼ 1.2 km thick marine record of the late Plio-Pleistocene that, unlike the land-based record, preserves an almost complete archive of erosion and deposition by Europe's ice sheets and large river systems. Thus, the sequence preserved in the NSB is a significant palaeoclimate archive of late Plio-Pleistocene climate–environmental linkages. While the NSB is extensively covered by industry data, the late Plio-Pleistocene interval lacks samples providing geological control on existing palaeoclimate interpretations. The International Ocean Drilling Programme (IODP3) Expedition 507 will unravel how glaciers, landscapes, climate, and ecosystems evolved and interacted through the late Plio-Pleistocene. The expedition will contribute knowledge on natural climate variability, analogues of past warmer climates, tipping points, and rates of change. The mid-latitude location of the NSB allows for linkages between low- and high-latitude records, and potential feedbacks and teleconnections of north-west European climate with other parts of the climate system – e.g. European ice sheet influence on North Atlantic storm tracks. A particular focus on ecosystem evolution will reveal climate- and biology-related feedbacks, resilience, recovery, and carbon cycle dynamics. The results will tie into the 2050 Science Framework through Strategic Objectives 3–5 and Flagship Initiative 1 (ground-truthing future climate change) and will contribute to better calibration of numerical Earth-system models, knowledge on climate sensitivity and variability, and a wider appreciation of feedbacks within the Earth system.