Evidence for an ice shelf covering the central Arctic Ocean during the penultimate glaciation
| Autor: | Carina Johansson, Jan Backman, Thomas M. Cronin, Leif G. Anderson, Tom Flodén, Larry A. Mayer, Björn Eriksson, Natalia Barrientos Macho, Alexey Khortov, Rezwan Mohammad, Göran Björk, Dennis Cherniykh, Johan Nilsson, Christian Stranne, R. Ananiev, Nina Kirchner, Helen K. Coxall, Kevin Jerram, Matt O'Regan, Igor Semiletov, A. V. Koshurnikov, Martin Jakobsson, Riko Noormets, Laura Gemery, Örjan Gustafsson |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Drift ice
geography Multidisciplinary geography.geographical_feature_category 010504 meteorology & atmospheric sciences Science General Physics and Astronomy General Chemistry Antarctic sea ice 010502 geochemistry & geophysics 01 natural sciences Arctic ice pack General Biochemistry Genetics and Molecular Biology Ice shelf Iceberg Article Oceanography Sea ice Cryosphere Ice sheet Geology 0105 earth and related environmental sciences |
| Zdroj: | Nature Communications Nature Communications, Vol 7, Iss 1, Pp 1-10 (2016) |
| ISSN: | 2041-1723 |
| Popis: | 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. The development of pan-Arctic Ocean ice shelves during peak glacials was proposed in the 1970s, an idea that has been disputed due to lack of evidence. Here, the authors present geophysical mapping data supporting the presence of such an ice shelf during the peak of the penultimate glaciation ∼140–160 ka. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|