Environmental and climate changes in Antarctica in the Geological Past
In the Cretaceous time, Antarctica was characterized by subtropical and tropical climate. The Early Eocene was warmest in the Antarctic history but this Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica at about 34 Ma ago. There...
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ftdoajarticles:oai:doaj.org/article:39acdc8a156349888d6e7ef7ef51bd5c 2023-05-15T14:13:32+02:00 Environmental and climate changes in Antarctica in the Geological Past G. L. Leitchenkov 2015-03-01T00:00:00Z https://doi.org/10.15356/2076-6734-2014-4-107-116 https://doaj.org/article/39acdc8a156349888d6e7ef7ef51bd5c RU rus Nauka https://ice-snow.igras.ru/jour/article/view/74 https://doaj.org/toc/2076-6734 https://doaj.org/toc/2412-3765 2076-6734 2412-3765 doi:10.15356/2076-6734-2014-4-107-116 https://doaj.org/article/39acdc8a156349888d6e7ef7ef51bd5c Лëд и снег, Vol 54, Iss 4, Pp 107-116 (2015) антарктида геолого-геофизические данные изменение климата ледниковый покров природная среда Science Q article 2015 ftdoajarticles https://doi.org/10.15356/2076-6734-2014-4-107-116 2023-03-19T01:40:13Z In the Cretaceous time, Antarctica was characterized by subtropical and tropical climate. The Early Eocene was warmest in the Antarctic history but this Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica at about 34 Ma ago. There is indirect evidence that small ice caps developed within central Antarctica in the Late Eocene (42−34 Ma). From the Early Oligocene to the Middle Miocene (34−13 Ma) ice sheet was wet-based and fluctuated considerably in volume, but about 14 m.y. ago it became dry-based and more stable. Seismic data collected on the East Antarctic margin give valuable information on dynamics of the past ice sheets. These data shows that the sedimentary cover of the western Wilkes Land margin includes a giant (c. 200 000 km2) deep-water fan which formed between c. 43 and 34 Ma ago. The average rate of sedimentation in the central part of fan was 230–250 m/m.y. Active input of terrigenous sediments into deep-water denotes high-energy fluvial system within the Wilkes Land. Emergence of this fluvial system evidences earliest glaciation in the Antarctic interior which fed full-flowing rivers. The thickness of strata deposited during post-Early Oligocene glaciations on the Antarctic margin generally reflects the averaged energy of depositional environments. The thickest sediments (up to 2.0 km, i.e. almost twice more than in other parts of East Antarctic margin) and inferred highest energy are seen in the central Cooperation Sea, on the central Wilkes Land margin and in the D'Urville Sea. The areas with the thickest post-Early Oligocene strata correlate with places where present-day ice discharge is highest, such as via the Lambert, Totten and Mertz/Ninnis Glaciers. The correlation points to high ice (and sediment) flux in the same areas since the Early Oligocene. Article in Journal/Newspaper Antarc* Antarctic Antarctica Cooperation Sea D'Urville Sea Ice Sheet Wilkes Land Антарктида Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) D'Urville Sea ENVELOPE(140.000,140.000,-65.000,-65.000) Cooperation Sea ENVELOPE(70.000,70.000,-67.000,-67.000) Ice and Snow 128 4 107 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
Russian |
topic |
антарктида геолого-геофизические данные изменение климата ледниковый покров природная среда Science Q |
spellingShingle |
антарктида геолого-геофизические данные изменение климата ледниковый покров природная среда Science Q G. L. Leitchenkov Environmental and climate changes in Antarctica in the Geological Past |
topic_facet |
антарктида геолого-геофизические данные изменение климата ледниковый покров природная среда Science Q |
description |
In the Cretaceous time, Antarctica was characterized by subtropical and tropical climate. The Early Eocene was warmest in the Antarctic history but this Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica at about 34 Ma ago. There is indirect evidence that small ice caps developed within central Antarctica in the Late Eocene (42−34 Ma). From the Early Oligocene to the Middle Miocene (34−13 Ma) ice sheet was wet-based and fluctuated considerably in volume, but about 14 m.y. ago it became dry-based and more stable. Seismic data collected on the East Antarctic margin give valuable information on dynamics of the past ice sheets. These data shows that the sedimentary cover of the western Wilkes Land margin includes a giant (c. 200 000 km2) deep-water fan which formed between c. 43 and 34 Ma ago. The average rate of sedimentation in the central part of fan was 230–250 m/m.y. Active input of terrigenous sediments into deep-water denotes high-energy fluvial system within the Wilkes Land. Emergence of this fluvial system evidences earliest glaciation in the Antarctic interior which fed full-flowing rivers. The thickness of strata deposited during post-Early Oligocene glaciations on the Antarctic margin generally reflects the averaged energy of depositional environments. The thickest sediments (up to 2.0 km, i.e. almost twice more than in other parts of East Antarctic margin) and inferred highest energy are seen in the central Cooperation Sea, on the central Wilkes Land margin and in the D'Urville Sea. The areas with the thickest post-Early Oligocene strata correlate with places where present-day ice discharge is highest, such as via the Lambert, Totten and Mertz/Ninnis Glaciers. The correlation points to high ice (and sediment) flux in the same areas since the Early Oligocene. |
format |
Article in Journal/Newspaper |
author |
G. L. Leitchenkov |
author_facet |
G. L. Leitchenkov |
author_sort |
G. L. Leitchenkov |
title |
Environmental and climate changes in Antarctica in the Geological Past |
title_short |
Environmental and climate changes in Antarctica in the Geological Past |
title_full |
Environmental and climate changes in Antarctica in the Geological Past |
title_fullStr |
Environmental and climate changes in Antarctica in the Geological Past |
title_full_unstemmed |
Environmental and climate changes in Antarctica in the Geological Past |
title_sort |
environmental and climate changes in antarctica in the geological past |
publisher |
Nauka |
publishDate |
2015 |
url |
https://doi.org/10.15356/2076-6734-2014-4-107-116 https://doaj.org/article/39acdc8a156349888d6e7ef7ef51bd5c |
long_lat |
ENVELOPE(120.000,120.000,-69.000,-69.000) ENVELOPE(140.000,140.000,-65.000,-65.000) ENVELOPE(70.000,70.000,-67.000,-67.000) |
geographic |
Antarctic The Antarctic Wilkes Land D'Urville Sea Cooperation Sea |
geographic_facet |
Antarctic The Antarctic Wilkes Land D'Urville Sea Cooperation Sea |
genre |
Antarc* Antarctic Antarctica Cooperation Sea D'Urville Sea Ice Sheet Wilkes Land Антарктида |
genre_facet |
Antarc* Antarctic Antarctica Cooperation Sea D'Urville Sea Ice Sheet Wilkes Land Антарктида |
op_source |
Лëд и снег, Vol 54, Iss 4, Pp 107-116 (2015) |
op_relation |
https://ice-snow.igras.ru/jour/article/view/74 https://doaj.org/toc/2076-6734 https://doaj.org/toc/2412-3765 2076-6734 2412-3765 doi:10.15356/2076-6734-2014-4-107-116 https://doaj.org/article/39acdc8a156349888d6e7ef7ef51bd5c |
op_doi |
https://doi.org/10.15356/2076-6734-2014-4-107-116 |
container_title |
Ice and Snow |
container_volume |
128 |
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4 |
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107 |
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