Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego

Autores
Unkel, Ingmar; Fernández, Marilén; Björck, Svante; Ljung, Karl; Wohlfarth, Barbara
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
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 around 7900 cal BP shows that the former wet land with peat accumulation had become a lake with a fairly rapid sedimentation. The chemical data from LGB imply a gradually increasing marine influence, probably as an effect of both rising sea level and increased impact of storms and maximum high tides. After a marine high-stand during the mid-Holocene, the LGB site returned into a peat bog again around 3400 cal BP. Our data suggest that since then relative sea level first dropped back below present sea level followed by a rise to present day sea level.
Fil: Unkel, Ingmar . Lund University; Suecia. Kiel University. Institute for Ecosystem Research; Alemania
Fil: Fernández, Marilén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Lund University; Suecia
Fil: Björck, Svante . Lund University; Suecia
Fil: Ljung, Karl. University of Bristol; Reino Unido. Lund University; Suecia
Fil: Wohlfarth, Barbara . Stockholms Universitet; Suecia
Materia
Holocene
Lake Sediments
Peat
Diatom Analysis
Xrf
Paleoclimate
Southern Westerlies
Sea Level Changes
Tierra del Fuego
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/12693

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network_name_str CONICET Digital (CONICET)
spelling Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del FuegoUnkel, Ingmar Fernández, MarilénBjörck, Svante Ljung, KarlWohlfarth, Barbara HoloceneLake SedimentsPeatDiatom AnalysisXrfPaleoclimateSouthern WesterliesSea Level ChangesTierra del Fuegohttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Southernmost 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 around 7900 cal BP shows that the former wet land with peat accumulation had become a lake with a fairly rapid sedimentation. The chemical data from LGB imply a gradually increasing marine influence, probably as an effect of both rising sea level and increased impact of storms and maximum high tides. After a marine high-stand during the mid-Holocene, the LGB site returned into a peat bog again around 3400 cal BP. Our data suggest that since then relative sea level first dropped back below present sea level followed by a rise to present day sea level.Fil: Unkel, Ingmar . Lund University; Suecia. Kiel University. Institute for Ecosystem Research; AlemaniaFil: Fernández, Marilén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Lund University; SueciaFil: Björck, Svante . Lund University; SueciaFil: Ljung, Karl. University of Bristol; Reino Unido. Lund University; SueciaFil: Wohlfarth, Barbara . Stockholms Universitet; SueciaElsevier Science2010-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/12693Unkel, 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; 99-1130921-8181enginfo:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0921818110001542info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gloplacha.2010.07.003info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:52:05Zoai:ri.conicet.gov.ar:11336/12693instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 09:52:05.468CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego
title Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego
spellingShingle Records of environmental changes during the Holocene from Isla de los Estados (54.4°S), southeastern Tierra del Fuego
Unkel, Ingmar
Holocene
Lake Sediments
Peat
Diatom Analysis
Xrf
Paleoclimate
Southern Westerlies
Sea Level Changes
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
dc.creator.none.fl_str_mv Unkel, Ingmar
Fernández, Marilén
Björck, Svante
Ljung, Karl
Wohlfarth, Barbara
author Unkel, Ingmar
author_facet Unkel, Ingmar
Fernández, Marilén
Björck, Svante
Ljung, Karl
Wohlfarth, Barbara
author_role author
author2 Fernández, Marilén
Björck, Svante
Ljung, Karl
Wohlfarth, Barbara
author2_role author
author
author
author
dc.subject.none.fl_str_mv Holocene
Lake Sediments
Peat
Diatom Analysis
Xrf
Paleoclimate
Southern Westerlies
Sea Level Changes
Tierra del Fuego
topic Holocene
Lake Sediments
Peat
Diatom Analysis
Xrf
Paleoclimate
Southern Westerlies
Sea Level Changes
Tierra del Fuego
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv 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 around 7900 cal BP shows that the former wet land with peat accumulation had become a lake with a fairly rapid sedimentation. The chemical data from LGB imply a gradually increasing marine influence, probably as an effect of both rising sea level and increased impact of storms and maximum high tides. After a marine high-stand during the mid-Holocene, the LGB site returned into a peat bog again around 3400 cal BP. Our data suggest that since then relative sea level first dropped back below present sea level followed by a rise to present day sea level.
Fil: Unkel, Ingmar . Lund University; Suecia. Kiel University. Institute for Ecosystem Research; Alemania
Fil: Fernández, Marilén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Lund University; Suecia
Fil: Björck, Svante . Lund University; Suecia
Fil: Ljung, Karl. University of Bristol; Reino Unido. Lund University; Suecia
Fil: Wohlfarth, Barbara . Stockholms Universitet; Suecia
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 around 7900 cal BP shows that the former wet land with peat accumulation had become a lake with a fairly rapid sedimentation. The chemical data from LGB imply a gradually increasing marine influence, probably as an effect of both rising sea level and increased impact of storms and maximum high tides. After a marine high-stand during the mid-Holocene, the LGB site returned into a peat bog again around 3400 cal BP. Our data suggest that since then relative sea level first dropped back below present sea level followed by a rise to present day sea level.
publishDate 2010
dc.date.none.fl_str_mv 2010-12
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv 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
url http://hdl.handle.net/11336/12693
identifier_str_mv 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
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 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
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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