Abstract
While there are numerous hypotheses concerning glacial–interglacial environmental and climatic regime shifts in the Arctic Ocean, a holistic view on the Northern Hemisphere's late Quaternary ice-sheet extent and their impact on ocean and sea-ice dynamics remains to be established. Here we aim to provide a step in this direction by presenting an overview of Arctic Ocean glacial history, based on the present state-of-the-art knowledge gained from field work and chronological studies, and with a specific focus on ice-sheet extent and environmental conditions during the Last Glacial Maximum (LGM). The maximum Quaternary extension of ice sheets is discussed and compared to LGM. We bring together recent results from the circum-Arctic continental margins and the deep central basin; extent of ice sheets and ice streams bordering the Arctic Ocean as well as evidence for ice shelves extending into the central deep basin. Discrepancies between new results and published LGM ice-sheet reconstructions in the high Arctic are highlighted and outstanding questions are identified. Finally, we address the ability to simulate the Arctic Ocean ice sheet complexes and their dynamics, including ice streams and ice shelves, using presently available ice-sheet models. Our review shows that while we are able to firmly reject some of the earlier hypotheses formulated to describe Arctic Ocean glacial conditions, we still lack information from key areas to compile the holistic Arctic Ocean glacial history.
Highlights
The glacial history of the Arctic Ocean involves the build-up and decay of marine-based ice sheets on the continental shelves, the development and disintegration of ice shelves, and significant changes in ocean-circulation regimes and sea-ice cover
This present circumpolar overview of glacial landforms, stratigraphies, and chronologies summarizes the current state of knowledge and identifies a set of outstanding questions arising from this synthesis
The question of huge ice shelves in the central Arctic Ocean and how these were fed from circumpolar margins is far from resolved
Summary
The glacial history of the Arctic Ocean involves the build-up and decay of marine-based ice sheets on the continental shelves, the development and disintegration of ice shelves, and significant changes in ocean-circulation regimes and sea-ice cover. Since the Arctic Palaeoclimate and its Extremes (APEX) program started in 2007 as a continuation of two preceding programs PONAM (The Late Cenozoic Evolution of the Polar North Atlantic Margins, 1988e1994 (Elverhøi et al, 1998a)) and QUEEN (the Quaternary Environment of the Eurasian North, 1996e 2002 (Thiede et al, 2004)) numerous field campaigns to the Arctic Ocean have been carried out (Jakobsson et al, 2010a) These have revealed new insights into the extent of ice sheets on the continental margins bordering the central Arctic Ocean, and how they fed into ice shelves that occupied regions of the central basin. The overarching question is what do we currently know about the past extent of ice sheets, ice streams and ice shelves, and related oceanographic changes, in the Arctic Ocean during the Quaternary? Which are the most important outstanding questions today? all data presented in our review allow us to revisit and shed new light on previous hypotheses regarding glacial conditions in the Arctic Ocean
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