Glacial onset predated Late Ordovician climate cooling
The Ordovician glaciation represents the acme of one of only three major icehouse periods in Earth's Phanerozoic history and is notorious for setting the scene for one of the big five mass extinction events. Nevertheless, the mechanisms that drove ice sheet growth remain poorly understood and t...
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ftunivgent:oai:archive.ugent.be:8057556 2023-06-11T04:05:59+02:00 Glacial onset predated Late Ordovician climate cooling Pohl, Alexandre Donnadieu, Yannick Le Hir, Guillaume Ladant, Jean-Baptiste Dumas, Christophe Alvarez-Solas, Jorge Vandenbroucke, Thijs 2016 application/pdf https://biblio.ugent.be/publication/8057556 http://hdl.handle.net/1854/LU-8057556 https://doi.org/10.1002/2016PA002928 https://biblio.ugent.be/publication/8057556/file/8057571 eng eng https://biblio.ugent.be/publication/8057556 http://hdl.handle.net/1854/LU-8057556 http://dx.doi.org/10.1002/2016PA002928 https://biblio.ugent.be/publication/8057556/file/8057571 No license (in copyright) info:eu-repo/semantics/openAccess PALEOCEANOGRAPHY ISSN: 0883-8305 Earth and Environmental Sciences Ordovician glaciation Earth system model pCO2 ANTARCTIC ICE-SHEET ATMOSPHERIC CARBON-DIOXIDE EARLY SILURIAN GLACIATION SEA-LEVEL RISE LAND PLANTS CO2 LEVELS MODEL CYCLE PALEOGEOGRAPHY PERIOD journalArticle info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2016 ftunivgent https://doi.org/10.1002/2016PA002928 2023-05-10T22:30:01Z The Ordovician glaciation represents the acme of one of only three major icehouse periods in Earth's Phanerozoic history and is notorious for setting the scene for one of the big five mass extinction events. Nevertheless, the mechanisms that drove ice sheet growth remain poorly understood and the final extent of the ice sheet crudely constrained. Here using an Earth system model with an innovative coupling method between ocean, atmosphere, and land ice accounting for climate and ice sheet feedback processes, we report simulations portraying for the first time the detailed evolution of the Ordovician ice sheet. We show that the emergence of the ice sheet happened in two discrete phases. In a counterintuitive sequence of events, the continental ice sheet appeared suddenly in a warm climate. Only during the second act, and set against a background of decreasing atmospheric CO2, followed steeply dropping temperatures and extending sea ice. The comparison with abundant sedimentological, geochemical, and micropaleontological data suggests that glacial onset may have occurred as early as the Middle Ordovician Darriwilian, in agreement with recent studies reporting third-order glacioeustatic cycles during the same period. The second step in ice sheet growth, typified by a sudden drop in tropical sea surface temperatures by approximate to 8 degrees C and the further extension of a single, continental-scale ice sheet over Gondwana, marked the onset of the Hirnantian glacial maximum. By suggesting the presence of an ice sheet over Gondwana throughout most of the Middle and Late Ordovician, our models embrace the emerging paradigm of an early Paleozoic Ice Age. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Sea ice Ghent University Academic Bibliography Antarctic Paleoceanography 31 6 800 821 |
institution |
Open Polar |
collection |
Ghent University Academic Bibliography |
op_collection_id |
ftunivgent |
language |
English |
topic |
Earth and Environmental Sciences Ordovician glaciation Earth system model pCO2 ANTARCTIC ICE-SHEET ATMOSPHERIC CARBON-DIOXIDE EARLY SILURIAN GLACIATION SEA-LEVEL RISE LAND PLANTS CO2 LEVELS MODEL CYCLE PALEOGEOGRAPHY PERIOD |
spellingShingle |
Earth and Environmental Sciences Ordovician glaciation Earth system model pCO2 ANTARCTIC ICE-SHEET ATMOSPHERIC CARBON-DIOXIDE EARLY SILURIAN GLACIATION SEA-LEVEL RISE LAND PLANTS CO2 LEVELS MODEL CYCLE PALEOGEOGRAPHY PERIOD Pohl, Alexandre Donnadieu, Yannick Le Hir, Guillaume Ladant, Jean-Baptiste Dumas, Christophe Alvarez-Solas, Jorge Vandenbroucke, Thijs Glacial onset predated Late Ordovician climate cooling |
topic_facet |
Earth and Environmental Sciences Ordovician glaciation Earth system model pCO2 ANTARCTIC ICE-SHEET ATMOSPHERIC CARBON-DIOXIDE EARLY SILURIAN GLACIATION SEA-LEVEL RISE LAND PLANTS CO2 LEVELS MODEL CYCLE PALEOGEOGRAPHY PERIOD |
description |
The Ordovician glaciation represents the acme of one of only three major icehouse periods in Earth's Phanerozoic history and is notorious for setting the scene for one of the big five mass extinction events. Nevertheless, the mechanisms that drove ice sheet growth remain poorly understood and the final extent of the ice sheet crudely constrained. Here using an Earth system model with an innovative coupling method between ocean, atmosphere, and land ice accounting for climate and ice sheet feedback processes, we report simulations portraying for the first time the detailed evolution of the Ordovician ice sheet. We show that the emergence of the ice sheet happened in two discrete phases. In a counterintuitive sequence of events, the continental ice sheet appeared suddenly in a warm climate. Only during the second act, and set against a background of decreasing atmospheric CO2, followed steeply dropping temperatures and extending sea ice. The comparison with abundant sedimentological, geochemical, and micropaleontological data suggests that glacial onset may have occurred as early as the Middle Ordovician Darriwilian, in agreement with recent studies reporting third-order glacioeustatic cycles during the same period. The second step in ice sheet growth, typified by a sudden drop in tropical sea surface temperatures by approximate to 8 degrees C and the further extension of a single, continental-scale ice sheet over Gondwana, marked the onset of the Hirnantian glacial maximum. By suggesting the presence of an ice sheet over Gondwana throughout most of the Middle and Late Ordovician, our models embrace the emerging paradigm of an early Paleozoic Ice Age. |
format |
Article in Journal/Newspaper |
author |
Pohl, Alexandre Donnadieu, Yannick Le Hir, Guillaume Ladant, Jean-Baptiste Dumas, Christophe Alvarez-Solas, Jorge Vandenbroucke, Thijs |
author_facet |
Pohl, Alexandre Donnadieu, Yannick Le Hir, Guillaume Ladant, Jean-Baptiste Dumas, Christophe Alvarez-Solas, Jorge Vandenbroucke, Thijs |
author_sort |
Pohl, Alexandre |
title |
Glacial onset predated Late Ordovician climate cooling |
title_short |
Glacial onset predated Late Ordovician climate cooling |
title_full |
Glacial onset predated Late Ordovician climate cooling |
title_fullStr |
Glacial onset predated Late Ordovician climate cooling |
title_full_unstemmed |
Glacial onset predated Late Ordovician climate cooling |
title_sort |
glacial onset predated late ordovician climate cooling |
publishDate |
2016 |
url |
https://biblio.ugent.be/publication/8057556 http://hdl.handle.net/1854/LU-8057556 https://doi.org/10.1002/2016PA002928 https://biblio.ugent.be/publication/8057556/file/8057571 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Ice Sheet Sea ice |
genre_facet |
Antarc* Antarctic Ice Sheet Sea ice |
op_source |
PALEOCEANOGRAPHY ISSN: 0883-8305 |
op_relation |
https://biblio.ugent.be/publication/8057556 http://hdl.handle.net/1854/LU-8057556 http://dx.doi.org/10.1002/2016PA002928 https://biblio.ugent.be/publication/8057556/file/8057571 |
op_rights |
No license (in copyright) info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1002/2016PA002928 |
container_title |
Paleoceanography |
container_volume |
31 |
container_issue |
6 |
container_start_page |
800 |
op_container_end_page |
821 |
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1768377703367442432 |