The Holocene hypsithermal in the Australian region
Close examination of key and well-dated Holocene sites, both on land and at sea in the Australian region indicate that at the very beginning of the Holocene, as a result of strong westerlies, there must have been a continuous positive Southern Annular Mode (SAM). Following from that, the entire regi...
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ftarchimer:oai:archimer.ifremer.fr:90527 2023-05-15T14:05:26+02:00 The Holocene hypsithermal in the Australian region De Deckker, Patrick 2022-07 application/pdf https://archimer.ifremer.fr/doc/00793/90527/96098.pdf https://archimer.ifremer.fr/doc/00793/90527/96218.pdf https://doi.org/10.1016/j.qsa.2022.100061 https://archimer.ifremer.fr/doc/00793/90527/ eng eng Elsevier BV https://archimer.ifremer.fr/doc/00793/90527/96098.pdf https://archimer.ifremer.fr/doc/00793/90527/96218.pdf doi:10.1016/j.qsa.2022.100061 https://archimer.ifremer.fr/doc/00793/90527/ info:eu-repo/semantics/openAccess restricted use Quaternary Science Advances (2666-0334) (Elsevier BV), 2022-07 , Vol. 7 , P. 100061 (12p.) Westerlies Holocene optimum Upwelling Sea-surface temperature Rainfall Pollen Rainforest Speleothem Southern annular mode Human population ENSO text Publication info:eu-repo/semantics/article 2022 ftarchimer https://doi.org/10.1016/j.qsa.2022.100061 2023-03-14T23:55:22Z Close examination of key and well-dated Holocene sites, both on land and at sea in the Australian region indicate that at the very beginning of the Holocene, as a result of strong westerlies, there must have been a continuous positive Southern Annular Mode (SAM). Following from that, the entire region switched to a negative SAM scenario and, during that time, the westerlies must have retreated further south. Afterwards, a period of time spaning ∼8200 to ∼5500 years ago temperatures were higher than today. We refer to it as the Holocene Hyspithermal. Coincident to this period, lake levels and postulated rainfall were extraordinarily high and vegetation spectra in places very different compared to today. The extent of this period varies by a few centuries between sites, but this may result from the level of resolution and also appears to be controlled by latitude. There is also clear indication that the influence of the westerlies was reduced over Australia during those two and a half millennia. Nevertheless, air temperatures recognised in Antarctic ice cores are at the opposite to those recognised in Australia. In addition, during the Australian Holocene Hypsithermal, CO2 levels were at their lowest in Antarctic ice cores. Climatic conditions then progressively deteriorated everywhere a bit after ∼6000 years BP until recent times as ENSO signals with alternating El Niño and La Niña conditions across the entire Pacific region as already described by Perner et al. (2018) based on the same cores studied here. Brief mention is also made to the presence of humans in SE Australia during the Holocene. It seems that human activities changed well after the period of high temperatures and rainfall, with more sedentary activities along the major rivers, with an enhancement of food production in organized settings suggestive of villages. Article in Journal/Newspaper Antarc* Antarctic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Antarctic Pacific Quaternary Science Advances 7 100061 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Westerlies Holocene optimum Upwelling Sea-surface temperature Rainfall Pollen Rainforest Speleothem Southern annular mode Human population ENSO |
spellingShingle |
Westerlies Holocene optimum Upwelling Sea-surface temperature Rainfall Pollen Rainforest Speleothem Southern annular mode Human population ENSO De Deckker, Patrick The Holocene hypsithermal in the Australian region |
topic_facet |
Westerlies Holocene optimum Upwelling Sea-surface temperature Rainfall Pollen Rainforest Speleothem Southern annular mode Human population ENSO |
description |
Close examination of key and well-dated Holocene sites, both on land and at sea in the Australian region indicate that at the very beginning of the Holocene, as a result of strong westerlies, there must have been a continuous positive Southern Annular Mode (SAM). Following from that, the entire region switched to a negative SAM scenario and, during that time, the westerlies must have retreated further south. Afterwards, a period of time spaning ∼8200 to ∼5500 years ago temperatures were higher than today. We refer to it as the Holocene Hyspithermal. Coincident to this period, lake levels and postulated rainfall were extraordinarily high and vegetation spectra in places very different compared to today. The extent of this period varies by a few centuries between sites, but this may result from the level of resolution and also appears to be controlled by latitude. There is also clear indication that the influence of the westerlies was reduced over Australia during those two and a half millennia. Nevertheless, air temperatures recognised in Antarctic ice cores are at the opposite to those recognised in Australia. In addition, during the Australian Holocene Hypsithermal, CO2 levels were at their lowest in Antarctic ice cores. Climatic conditions then progressively deteriorated everywhere a bit after ∼6000 years BP until recent times as ENSO signals with alternating El Niño and La Niña conditions across the entire Pacific region as already described by Perner et al. (2018) based on the same cores studied here. Brief mention is also made to the presence of humans in SE Australia during the Holocene. It seems that human activities changed well after the period of high temperatures and rainfall, with more sedentary activities along the major rivers, with an enhancement of food production in organized settings suggestive of villages. |
format |
Article in Journal/Newspaper |
author |
De Deckker, Patrick |
author_facet |
De Deckker, Patrick |
author_sort |
De Deckker, Patrick |
title |
The Holocene hypsithermal in the Australian region |
title_short |
The Holocene hypsithermal in the Australian region |
title_full |
The Holocene hypsithermal in the Australian region |
title_fullStr |
The Holocene hypsithermal in the Australian region |
title_full_unstemmed |
The Holocene hypsithermal in the Australian region |
title_sort |
holocene hypsithermal in the australian region |
publisher |
Elsevier BV |
publishDate |
2022 |
url |
https://archimer.ifremer.fr/doc/00793/90527/96098.pdf https://archimer.ifremer.fr/doc/00793/90527/96218.pdf https://doi.org/10.1016/j.qsa.2022.100061 https://archimer.ifremer.fr/doc/00793/90527/ |
geographic |
Antarctic Pacific |
geographic_facet |
Antarctic Pacific |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Quaternary Science Advances (2666-0334) (Elsevier BV), 2022-07 , Vol. 7 , P. 100061 (12p.) |
op_relation |
https://archimer.ifremer.fr/doc/00793/90527/96098.pdf https://archimer.ifremer.fr/doc/00793/90527/96218.pdf doi:10.1016/j.qsa.2022.100061 https://archimer.ifremer.fr/doc/00793/90527/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1016/j.qsa.2022.100061 |
container_title |
Quaternary Science Advances |
container_volume |
7 |
container_start_page |
100061 |
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1766277333569765376 |