Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego
Southernmost Patagonia, located at the relatively narrow passage between Antarctica and South America, is a highly sensitive region for recording meridional and zonal changes in the pattern of oceanic and atmospheric circulation. The island of Isla de los Estados, situated at 54.5 degrees S, 64 degr...
Published in: | Global and Planetary Change |
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Format: | Article in Journal/Newspaper |
Language: | English |
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2010
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Online Access: | https://lup.lub.lu.se/record/1811477 https://doi.org/10.1016/j.gloplacha.2010.07.003 |
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ftulundlup:oai:lup.lub.lu.se:23ccd254-a055-479d-b906-5b719e9119c5 2023-05-15T13:35:34+02:00 Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego Unkel, Ingmar Fernandez, Marilen Björck, Svante Ljung, Karl Wohlfarth, Barbara 2010 https://lup.lub.lu.se/record/1811477 https://doi.org/10.1016/j.gloplacha.2010.07.003 eng eng Elsevier https://lup.lub.lu.se/record/1811477 http://dx.doi.org/10.1016/j.gloplacha.2010.07.003 wos:000285909100001 scopus:78649634552 Global and Planetary Change; 74(3-4), pp 99-113 (2010) ISSN: 1872-6364 Geology Tierra del Fuego sea-level changes southern westerlies paleoclimate XRF diatom analysis peat lake sediments Holocene contributiontojournal/article info:eu-repo/semantics/article text 2010 ftulundlup https://doi.org/10.1016/j.gloplacha.2010.07.003 2023-02-01T23:29:22Z Southernmost Patagonia, located at the relatively narrow passage between Antarctica and South America, is a highly sensitive region for recording meridional and zonal changes in the pattern of oceanic and atmospheric circulation. The island of Isla de los Estados, situated at 54.5 degrees S, 64 degrees W, east of Argentinean Tierra del Fuego, provides an exceptional possibility, to investigate terrestrial records of atmospheric conditions in an oceanic setting during the last deglaciation and the Holocene. Here we present geochemical and diatom analyses from 10600 to c. 1500 cal BP of one sequence (LGB) with peat, lake sediments and lagoon deposits at the northern coast of the island, and a lake sediment sequence (CAS) 3 km further inland. The data comprise TC, TN, loss on ignition analyses and continuous XRF scanning as well as age-depth modeling based on AMS-C-14 dating on both cores. Diatom analysis of the CAS record complements the geochemical proxies. During the Holocene, our two sites have been impacted by two different forcings: changes in the regional climate regime largely influenced by the varying strength and position of the Southern Hemisphere Westerlies (SHW), while relative sea-level changes affected the deposits of the coastal site. In concert with the onset of the Antarctic thermal optimum, our data suggest fairly warm conditions and the establishment of denser peat and forest vegetation on the island c. 10600 cal BP. Between 8500 and 4500 cal BP geochemistry and diatoms from the CAS record indicate stronger Westerlies at this latitude, which means higher wind speed or higher storm frequency and more precipitation, resulting in more pronounced surface run-off. After 4500 cal BP, the geochemical proxies and large changes in diatom assemblages indicate a decrease in precipitation, weaker winds and possibly cooler conditions, probably as an effect of weaker SHW and/or a latitudinal shift. The depositional environment of CAS changed from gyttja to peat around 1000 cal BP. At LGB, the onset of gyttja ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Tierra del Fuego Lund University Publications (LUP) Antarctic Island C ENVELOPE(-115.753,-115.753,60.834,60.834) Narrow Passage ENVELOPE(-79.266,-79.266,55.684,55.684) Patagonia Peat Lake ENVELOPE(-137.390,-137.390,68.919,68.919) The Antarctic Global and Planetary Change 74 3-4 99 113 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology Tierra del Fuego sea-level changes southern westerlies paleoclimate XRF diatom analysis peat lake sediments Holocene |
spellingShingle |
Geology Tierra del Fuego sea-level changes southern westerlies paleoclimate XRF diatom analysis peat lake sediments Holocene Unkel, Ingmar Fernandez, Marilen Björck, Svante Ljung, Karl Wohlfarth, Barbara Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego |
topic_facet |
Geology Tierra del Fuego sea-level changes southern westerlies paleoclimate XRF diatom analysis peat lake sediments Holocene |
description |
Southernmost Patagonia, located at the relatively narrow passage between Antarctica and South America, is a highly sensitive region for recording meridional and zonal changes in the pattern of oceanic and atmospheric circulation. The island of Isla de los Estados, situated at 54.5 degrees S, 64 degrees W, east of Argentinean Tierra del Fuego, provides an exceptional possibility, to investigate terrestrial records of atmospheric conditions in an oceanic setting during the last deglaciation and the Holocene. Here we present geochemical and diatom analyses from 10600 to c. 1500 cal BP of one sequence (LGB) with peat, lake sediments and lagoon deposits at the northern coast of the island, and a lake sediment sequence (CAS) 3 km further inland. The data comprise TC, TN, loss on ignition analyses and continuous XRF scanning as well as age-depth modeling based on AMS-C-14 dating on both cores. Diatom analysis of the CAS record complements the geochemical proxies. During the Holocene, our two sites have been impacted by two different forcings: changes in the regional climate regime largely influenced by the varying strength and position of the Southern Hemisphere Westerlies (SHW), while relative sea-level changes affected the deposits of the coastal site. In concert with the onset of the Antarctic thermal optimum, our data suggest fairly warm conditions and the establishment of denser peat and forest vegetation on the island c. 10600 cal BP. Between 8500 and 4500 cal BP geochemistry and diatoms from the CAS record indicate stronger Westerlies at this latitude, which means higher wind speed or higher storm frequency and more precipitation, resulting in more pronounced surface run-off. After 4500 cal BP, the geochemical proxies and large changes in diatom assemblages indicate a decrease in precipitation, weaker winds and possibly cooler conditions, probably as an effect of weaker SHW and/or a latitudinal shift. The depositional environment of CAS changed from gyttja to peat around 1000 cal BP. At LGB, the onset of gyttja ... |
format |
Article in Journal/Newspaper |
author |
Unkel, Ingmar Fernandez, Marilen Björck, Svante Ljung, Karl Wohlfarth, Barbara |
author_facet |
Unkel, Ingmar Fernandez, Marilen Björck, Svante Ljung, Karl Wohlfarth, Barbara |
author_sort |
Unkel, Ingmar |
title |
Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego |
title_short |
Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego |
title_full |
Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego |
title_fullStr |
Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego |
title_full_unstemmed |
Records of environmental changes during the Holocene from Isla de los Estados (54.4 degrees S), southeastern Tierra del Fuego |
title_sort |
records of environmental changes during the holocene from isla de los estados (54.4 degrees s), southeastern tierra del fuego |
publisher |
Elsevier |
publishDate |
2010 |
url |
https://lup.lub.lu.se/record/1811477 https://doi.org/10.1016/j.gloplacha.2010.07.003 |
long_lat |
ENVELOPE(-115.753,-115.753,60.834,60.834) ENVELOPE(-79.266,-79.266,55.684,55.684) ENVELOPE(-137.390,-137.390,68.919,68.919) |
geographic |
Antarctic Island C Narrow Passage Patagonia Peat Lake The Antarctic |
geographic_facet |
Antarctic Island C Narrow Passage Patagonia Peat Lake The Antarctic |
genre |
Antarc* Antarctic Antarctica Tierra del Fuego |
genre_facet |
Antarc* Antarctic Antarctica Tierra del Fuego |
op_source |
Global and Planetary Change; 74(3-4), pp 99-113 (2010) ISSN: 1872-6364 |
op_relation |
https://lup.lub.lu.se/record/1811477 http://dx.doi.org/10.1016/j.gloplacha.2010.07.003 wos:000285909100001 scopus:78649634552 |
op_doi |
https://doi.org/10.1016/j.gloplacha.2010.07.003 |
container_title |
Global and Planetary Change |
container_volume |
74 |
container_issue |
3-4 |
container_start_page |
99 |
op_container_end_page |
113 |
_version_ |
1766067259550203904 |