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Evidence for an ice shelf covering the central Arctic Ocean during the penultimate glaciation

Martin Jakobsson·Johan Nilsson·Leif G. Anderson·Jan Backman·Goran Bjork·Thomas M. Cronin·Nina Kirchner·Andrey Koshurnikov·Larry Mayer·Riko Noormets·Matthew O’Regan·Christian Stranne·Roman Ananiev·Natalia Barrientos Macho·Dennis Cherniykh·Helen Coxall·Bjorn Eriksson·Tom Floden·Laura Gemery·Orjan Gustafsson·Kevin Jerram·Carina Johansson·Alexey Khortov·Rezwan Mohammad·Igor Semiletov
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Abstract

The hypothesis of a km-thick ice shelf covering the entire Arctic Ocean during peak glacial conditions was proposed nearly half a century ago. Floating ice shelves preserve few direct traces after their disappearance, making reconstructions difficult. Seafloor imprints of ice shelves should, however, exist where ice grounded along their flow paths. Here we present new evidence of ice-shelf groundings on bathymetric highs in the central Arctic Ocean, resurrecting the concept of an ice shelf extending over the entire central Arctic Ocean during at least one previous ice age. New and previously mapped glacial landforms together reveal flow of a spatially coherent, in some regions >1-km thick, central Arctic Ocean ice shelf dated to marine isotope stage 6 (~140 ka). Bathymetric highs were likely critical in the ice-shelf development by acting as pinning points where stabilizing ice rises formed, thereby providing sufficient back stress to allow ice shelf thickening.

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Martin Jakobsson, Johan Nilsson, Leif G. Anderson, Jan Backman, Goran Bjork, Thomas M. Cronin, Nina Kirchner, Andrey Koshurnikov, Larry Mayer, Riko Noormets, Matthew O’Regan, Christian Stranne, Roman Ananiev, Natalia Barrientos Macho, Dennis Cherniykh, Helen Coxall, Bjorn Eriksson, Tom Floden, Laura Gemery, Orjan Gustafsson, Kevin Jerram, Carina Johansson, Alexey Khortov, Rezwan Mohammad, Igor Semiletov. 2016-01-18. Evidence for an ice shelf covering the central Arctic Ocean during the penultimate glaciation. https://doi.org/10.1038/ncomms10365

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