Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr.
International audience Even though Patagonia is ideally located to study climate of the southern mid-latitudes, many questions on the late Quaternary climate evolution remain unresolved. The timing of maximum glacier extent is still uncertain in vast areas, and the postglacial evolution of the South...
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ftunivnantes:oai:HAL:hal-01319270v1 2023-05-15T16:41:32+02:00 Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr. van Daele, M. Bertrand, S. Meyer, I. Moernaut, J. Vandoome, W. Siani, G. Tanghe, N. Ghazoui, Z. Pino, M. Urrutia, R. de Batist, M. Renard Centre of Marine Geology Universiteit Gent = Ghent University Belgium (UGENT) Géosciences Paris Sud (GEOPS) Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) 2016 https://hal.archives-ouvertes.fr/hal-01319270 en eng HAL CCSD Elsevier hal-01319270 https://hal.archives-ouvertes.fr/hal-01319270 ISSN: 0277-3791 Quaternary Science Reviews https://hal.archives-ouvertes.fr/hal-01319270 Quaternary Science Reviews, Elsevier, 2016, 133: (130-146 (IF 4,572)) [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2016 ftunivnantes 2022-10-12T00:00:40Z International audience Even though Patagonia is ideally located to study climate of the southern mid-latitudes, many questions on the late Quaternary climate evolution remain unresolved. The timing of maximum glacier extent is still uncertain in vast areas, and the postglacial evolution of the Southern Westerly Wind Belt (SWWB) remains highly debated. Here, we study the sedimentary infill of a glacigenic lake (Lago Castor; 45.6°S, 71.8°W) located at the leeside of the Andes in Chilean Patagonia to i) reconstruct the deglacial evolution of the eastern flank of the Patagonian Ice Sheet (PIS), and ii) discuss postglacial changes in wind strength at a critical location where westerly wind records are critically lacking. A dense grid of high-resolution reflection-seismic data was used to reconstruct the large-scale infill history of the lake, and a radiocarbon dated sediment core penetrating all lacustrine seismic units, was retrieved. Results indicate that the deglaciation of the lake basin and its catchment occurred no later than ∼28 cal kyr BP (i.e. an early LGM), but possibly even already after MIS 4. Afterwards, the Lago Castor area was covered by a large proglacial lake that drained – possibly through an outburst flood – when the PIS outlet glaciers retreated to a critical location. Subsequently, very dry conditions caused the lake to desiccate, as evidenced by an unconformity visible on the seismic profiles and in the sediment core. This dry period likely resulted from the increased orographic effect of the PIS-covered Andes, accompanied by weaker westerlies. From ∼20 kyr BP onwards, the combination of a shrinking PIS and a southward shift of the SWWB resulted in increased precipitation, which caused the lake level to rise. After ∼17 cal kyr BP, lake sedimentation was more directly influenced by the southern westerlies, with the formation of sediment drifts resulting from strong bottom current during periods of intense westerly winds. Our results suggest a progressive increase in wind strength at 46°S from ... Article in Journal/Newspaper Ice Sheet Université de Nantes: HAL-UNIV-NANTES Patagonia |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] van Daele, M. Bertrand, S. Meyer, I. Moernaut, J. Vandoome, W. Siani, G. Tanghe, N. Ghazoui, Z. Pino, M. Urrutia, R. de Batist, M. Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr. |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience Even though Patagonia is ideally located to study climate of the southern mid-latitudes, many questions on the late Quaternary climate evolution remain unresolved. The timing of maximum glacier extent is still uncertain in vast areas, and the postglacial evolution of the Southern Westerly Wind Belt (SWWB) remains highly debated. Here, we study the sedimentary infill of a glacigenic lake (Lago Castor; 45.6°S, 71.8°W) located at the leeside of the Andes in Chilean Patagonia to i) reconstruct the deglacial evolution of the eastern flank of the Patagonian Ice Sheet (PIS), and ii) discuss postglacial changes in wind strength at a critical location where westerly wind records are critically lacking. A dense grid of high-resolution reflection-seismic data was used to reconstruct the large-scale infill history of the lake, and a radiocarbon dated sediment core penetrating all lacustrine seismic units, was retrieved. Results indicate that the deglaciation of the lake basin and its catchment occurred no later than ∼28 cal kyr BP (i.e. an early LGM), but possibly even already after MIS 4. Afterwards, the Lago Castor area was covered by a large proglacial lake that drained – possibly through an outburst flood – when the PIS outlet glaciers retreated to a critical location. Subsequently, very dry conditions caused the lake to desiccate, as evidenced by an unconformity visible on the seismic profiles and in the sediment core. This dry period likely resulted from the increased orographic effect of the PIS-covered Andes, accompanied by weaker westerlies. From ∼20 kyr BP onwards, the combination of a shrinking PIS and a southward shift of the SWWB resulted in increased precipitation, which caused the lake level to rise. After ∼17 cal kyr BP, lake sedimentation was more directly influenced by the southern westerlies, with the formation of sediment drifts resulting from strong bottom current during periods of intense westerly winds. Our results suggest a progressive increase in wind strength at 46°S from ... |
author2 |
Renard Centre of Marine Geology Universiteit Gent = Ghent University Belgium (UGENT) Géosciences Paris Sud (GEOPS) Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
van Daele, M. Bertrand, S. Meyer, I. Moernaut, J. Vandoome, W. Siani, G. Tanghe, N. Ghazoui, Z. Pino, M. Urrutia, R. de Batist, M. |
author_facet |
van Daele, M. Bertrand, S. Meyer, I. Moernaut, J. Vandoome, W. Siani, G. Tanghe, N. Ghazoui, Z. Pino, M. Urrutia, R. de Batist, M. |
author_sort |
van Daele, M. |
title |
Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr. |
title_short |
Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr. |
title_full |
Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr. |
title_fullStr |
Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr. |
title_full_unstemmed |
Late Quaternary evolution of Lago Castor (Chile, 45.6°S) : timing of the deglaciation in northern Patagonia and evolution of the westerlies during the last 17 kyr. |
title_sort |
late quaternary evolution of lago castor (chile, 45.6°s) : timing of the deglaciation in northern patagonia and evolution of the westerlies during the last 17 kyr. |
publisher |
HAL CCSD |
publishDate |
2016 |
url |
https://hal.archives-ouvertes.fr/hal-01319270 |
geographic |
Patagonia |
geographic_facet |
Patagonia |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
ISSN: 0277-3791 Quaternary Science Reviews https://hal.archives-ouvertes.fr/hal-01319270 Quaternary Science Reviews, Elsevier, 2016, 133: (130-146 (IF 4,572)) |
op_relation |
hal-01319270 https://hal.archives-ouvertes.fr/hal-01319270 |
_version_ |
1766031979712610304 |