Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation
Two global glaciations occurred during the Neoproterozoic. Snowball Earth theory posits that these were terminated after millions of years of frigidity when initial warming from rising atmospheric CO2concentrations was amplified by the reduction of ice cover and hence a reduction in planetary albedo...
Published in: | Nature Geoscience |
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Online Access: | https://digitalcommons.lsu.edu/geo_pubs/218 https://doi.org/10.1038/ngeo2502 https://digitalcommons.lsu.edu/context/geo_pubs/article/1217/viewcontent/218.pdf |
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ftlouisianastuir:oai:digitalcommons.lsu.edu:geo_pubs-1217 2023-06-11T04:03:15+02:00 Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation Benn, Douglas I. Le Hir, Guillaume Bao, Huiming Donnadieu, Yannick Dumas, Christophe Fleming, Edward J. Hambrey, Michael J. McMillan, Emily A. Petronis, Michael S. Ramstein, Gilles Stevenson, Carl T.E. Wynn, Peter M. Fairchild, Ian J. 2015-01-01T08:00:00Z application/pdf https://digitalcommons.lsu.edu/geo_pubs/218 https://doi.org/10.1038/ngeo2502 https://digitalcommons.lsu.edu/context/geo_pubs/article/1217/viewcontent/218.pdf unknown LSU Digital Commons https://digitalcommons.lsu.edu/geo_pubs/218 doi:10.1038/ngeo2502 https://digitalcommons.lsu.edu/context/geo_pubs/article/1217/viewcontent/218.pdf Faculty Publications text 2015 ftlouisianastuir https://doi.org/10.1038/ngeo2502 2023-05-28T18:24:40Z Two global glaciations occurred during the Neoproterozoic. Snowball Earth theory posits that these were terminated after millions of years of frigidity when initial warming from rising atmospheric CO2concentrations was amplified by the reduction of ice cover and hence a reduction in planetary albedo. This scenario implies that most of the geological record of ice cover was deposited in a brief period of melt-back. However, deposits in low palaeo-latitudes show evidence of glacial-interglacial cycles. Here we analyse the sedimentology and oxygen and sulphur isotopic signatures of Marinoan Snowball glaciation deposits from Svalbard, in the Norwegian High Arctic. The deposits preserve a record of oscillations in glacier extent and hydrologic conditions under uniformly high atmospheric CO2concentrations. We use simulations from a coupled three-dimensional ice sheet and atmospheric general circulation model to show that such oscillations can be explained by orbital forcing in the late stages of a Snowball glaciation. The simulations suggest that while atmospheric CO2concentrations were rising, but not yet at the threshold required for complete melt-back, the ice sheets would have been sensitive to orbital forcing. We conclude that a similar dynamic can potentially explain the complex successions observed at other localities. Text albedo Arctic glacier Ice Sheet Svalbard LSU Digital Commons (Louisiana State University) Arctic Svalbard Nature Geoscience 8 9 704 707 |
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LSU Digital Commons (Louisiana State University) |
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description |
Two global glaciations occurred during the Neoproterozoic. Snowball Earth theory posits that these were terminated after millions of years of frigidity when initial warming from rising atmospheric CO2concentrations was amplified by the reduction of ice cover and hence a reduction in planetary albedo. This scenario implies that most of the geological record of ice cover was deposited in a brief period of melt-back. However, deposits in low palaeo-latitudes show evidence of glacial-interglacial cycles. Here we analyse the sedimentology and oxygen and sulphur isotopic signatures of Marinoan Snowball glaciation deposits from Svalbard, in the Norwegian High Arctic. The deposits preserve a record of oscillations in glacier extent and hydrologic conditions under uniformly high atmospheric CO2concentrations. We use simulations from a coupled three-dimensional ice sheet and atmospheric general circulation model to show that such oscillations can be explained by orbital forcing in the late stages of a Snowball glaciation. The simulations suggest that while atmospheric CO2concentrations were rising, but not yet at the threshold required for complete melt-back, the ice sheets would have been sensitive to orbital forcing. We conclude that a similar dynamic can potentially explain the complex successions observed at other localities. |
format |
Text |
author |
Benn, Douglas I. Le Hir, Guillaume Bao, Huiming Donnadieu, Yannick Dumas, Christophe Fleming, Edward J. Hambrey, Michael J. McMillan, Emily A. Petronis, Michael S. Ramstein, Gilles Stevenson, Carl T.E. Wynn, Peter M. Fairchild, Ian J. |
spellingShingle |
Benn, Douglas I. Le Hir, Guillaume Bao, Huiming Donnadieu, Yannick Dumas, Christophe Fleming, Edward J. Hambrey, Michael J. McMillan, Emily A. Petronis, Michael S. Ramstein, Gilles Stevenson, Carl T.E. Wynn, Peter M. Fairchild, Ian J. Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation |
author_facet |
Benn, Douglas I. Le Hir, Guillaume Bao, Huiming Donnadieu, Yannick Dumas, Christophe Fleming, Edward J. Hambrey, Michael J. McMillan, Emily A. Petronis, Michael S. Ramstein, Gilles Stevenson, Carl T.E. Wynn, Peter M. Fairchild, Ian J. |
author_sort |
Benn, Douglas I. |
title |
Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation |
title_short |
Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation |
title_full |
Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation |
title_fullStr |
Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation |
title_full_unstemmed |
Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation |
title_sort |
orbitally forced ice sheet fluctuations during the marinoan snowball earth glaciation |
publisher |
LSU Digital Commons |
publishDate |
2015 |
url |
https://digitalcommons.lsu.edu/geo_pubs/218 https://doi.org/10.1038/ngeo2502 https://digitalcommons.lsu.edu/context/geo_pubs/article/1217/viewcontent/218.pdf |
geographic |
Arctic Svalbard |
geographic_facet |
Arctic Svalbard |
genre |
albedo Arctic glacier Ice Sheet Svalbard |
genre_facet |
albedo Arctic glacier Ice Sheet Svalbard |
op_source |
Faculty Publications |
op_relation |
https://digitalcommons.lsu.edu/geo_pubs/218 doi:10.1038/ngeo2502 https://digitalcommons.lsu.edu/context/geo_pubs/article/1217/viewcontent/218.pdf |
op_doi |
https://doi.org/10.1038/ngeo2502 |
container_title |
Nature Geoscience |
container_volume |
8 |
container_issue |
9 |
container_start_page |
704 |
op_container_end_page |
707 |
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1768378018315632640 |