Records of environmental changes during the Holocene from Isla de los Estados (54.4°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°S, 64°W, east of A...
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ftconicet:oai:ri.conicet.gov.ar:11336/12693 2023-10-09T21:47:16+02:00 Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego Unkel, Ingmar Fernández, Marilén Björck, Svante Ljung, Karl Wohlfarth, Barbara application/pdf http://hdl.handle.net/11336/12693 eng eng Elsevier Science info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0921818110001542 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gloplacha.2010.07.003 http://hdl.handle.net/11336/12693 Unkel, Ingmar Fernández, Marilén; Björck, Svante Ljung, Karl; Wohlfarth, Barbara Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego; Elsevier Science; Global And Planetary Change; 74; 3-4; 12-2010; 99-113 0921-8181 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-nd/2.5/ar/ Holocene Lake Sediments Peat Diatom Analysis Xrf Paleoclimate Southern Westerlies Sea Level Changes Tierra del Fuego https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion ftconicet https://doi.org/10.1016/j.gloplacha.2010.07.003 2023-09-24T18:55:42Z 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°S, 64°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 10 600 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-14C 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. 10 600 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 sedimentation ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Tierra del Fuego CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) Antarctic The Antarctic Patagonia Island C ENVELOPE(-115.753,-115.753,60.834,60.834) Narrow Passage ENVELOPE(-79.266,-79.266,55.684,55.684) Peat Lake ENVELOPE(-137.390,-137.390,68.919,68.919) Global and Planetary Change 74 3-4 99 113 |
institution |
Open Polar |
collection |
CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) |
op_collection_id |
ftconicet |
language |
English |
topic |
Holocene Lake Sediments Peat Diatom Analysis Xrf Paleoclimate Southern Westerlies Sea Level Changes Tierra del Fuego https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
spellingShingle |
Holocene Lake Sediments Peat Diatom Analysis Xrf Paleoclimate Southern Westerlies Sea Level Changes Tierra del Fuego https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 Unkel, Ingmar Fernández, Marilén Björck, Svante Ljung, Karl Wohlfarth, Barbara Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego |
topic_facet |
Holocene Lake Sediments Peat Diatom Analysis Xrf Paleoclimate Southern Westerlies Sea Level Changes Tierra del Fuego https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
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°S, 64°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 10 600 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-14C 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. 10 600 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 sedimentation ... |
format |
Article in Journal/Newspaper |
author |
Unkel, Ingmar Fernández, Marilén Björck, Svante Ljung, Karl Wohlfarth, Barbara |
author_facet |
Unkel, Ingmar Fernández, Marilén 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°S), southeastern Tierra del Fuego |
title_short |
Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego |
title_full |
Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego |
title_fullStr |
Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego |
title_full_unstemmed |
Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego |
title_sort |
records of environmental changes during the holocene from isla de los estados (54.4°s), southeastern tierra del fuego |
publisher |
Elsevier Science |
url |
http://hdl.handle.net/11336/12693 |
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 The Antarctic Patagonia Island C Narrow Passage Peat Lake |
geographic_facet |
Antarctic The Antarctic Patagonia Island C Narrow Passage Peat Lake |
genre |
Antarc* Antarctic Antarctica Tierra del Fuego |
genre_facet |
Antarc* Antarctic Antarctica Tierra del Fuego |
op_relation |
info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0921818110001542 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gloplacha.2010.07.003 http://hdl.handle.net/11336/12693 Unkel, Ingmar Fernández, Marilén; Björck, Svante Ljung, Karl; Wohlfarth, Barbara Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego; Elsevier Science; Global And Planetary Change; 74; 3-4; 12-2010; 99-113 0921-8181 |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-nd/2.5/ar/ |
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_ |
1779310266843922432 |