Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation
Isla de los Estados (54A degrees 45'S, 63A degrees 10'aEuro"64A degrees 46'W) lies east of the main island of Tierra del Fuego and is the southeastern-most point in Argentina. Because of its geographic position near the latitudes of the Southern Hemisphere Westerlies and the stro...
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Online Access: | https://lup.lub.lu.se/record/4197940 https://doi.org/10.1007/s10933-013-9736-4 |
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ftulundlup:oai:lup.lub.lu.se:187aa38a-684c-461d-b54d-75654f518f55 2023-05-15T13:48:54+02:00 Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation Fernandez, Marilen Björck, Svante Wohlfarth, Barbara Maidana, Nora I. Unkel, Ingmar Van der Putten, Nathalie 2013 https://lup.lub.lu.se/record/4197940 https://doi.org/10.1007/s10933-013-9736-4 eng eng Springer https://lup.lub.lu.se/record/4197940 http://dx.doi.org/10.1007/s10933-013-9736-4 wos:000326622200002 scopus:84887317713 Journal of Paleolimnology; 50(4), pp 433-446 (2013) ISSN: 0921-2728 Geology Diatoms Biogenic silica Isla de los Estados Late glacial-early Holocene Paleoenvironments contributiontojournal/article info:eu-repo/semantics/article text 2013 ftulundlup https://doi.org/10.1007/s10933-013-9736-4 2023-02-01T23:27:05Z Isla de los Estados (54A degrees 45'S, 63A degrees 10'aEuro"64A degrees 46'W) lies east of the main island of Tierra del Fuego and is the southeastern-most point in Argentina. Because of its geographic position near the latitudes of the Southern Hemisphere Westerlies and the strong influence of the Antarctic Circumpolar Current (ACC), the area is suitable for paleoecological and paleoclimate research. The island is not far north of the Subantarctic Front, which limits the northern boundary of the ACC. Paleoenvironmental study in this geographic location can shed light on past changes in atmospheric and marine circulation patterns. Diatom analysis of the lower part of a sediment sequence from Laguna Cascada (54A degrees 45' 51.3''S, 64A degrees 20' 20.07''W) enabled inference of changing lake conditions between 16 and 11.1 cal ka BP. Between 16 and 14.4 cal ka BP fragilarioid diatom species, often a pioneer group, dominated the record. Their presence shows seasonally open-water conditions from the onset of sedimentation. In zone II (14.4-12.8 cal ka BP), the dominance of planktonic/tychoplanktonic Aulacoseira spp. might represent longer ice-free periods and windier conditions, which would have kept this heavy species suspended in the water column. This period corresponds to the Antarctic Cold Reversal, when the Southern Hemisphere Westerlies were possibly centered on the latitudes of Tierra del Fuego, resulting in windy and wet conditions. Zone III (12.8-11.1 cal ka BP) is dominated by benthic diatom taxa that are mainly associated with peat and wetland vegetation. This suggests that climate conditions had become milder and less windy, favoring aquatic productivity and terrestrial vegetation development. This change in environmental conditions may have been a consequence of the southward movement of the Southern Hemisphere Westerlies at the start of the Antarctic Holocene thermal optimum. Article in Journal/Newspaper Antarc* Antarctic Tierra del Fuego Lund University Publications (LUP) Antarctic Argentina Changing Lake ENVELOPE(-45.619,-45.619,-60.708,-60.708) Main Island ENVELOPE(-38.220,-38.220,-54.007,-54.007) The Antarctic Journal of Paleolimnology 50 4 433 446 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology Diatoms Biogenic silica Isla de los Estados Late glacial-early Holocene Paleoenvironments |
spellingShingle |
Geology Diatoms Biogenic silica Isla de los Estados Late glacial-early Holocene Paleoenvironments Fernandez, Marilen Björck, Svante Wohlfarth, Barbara Maidana, Nora I. Unkel, Ingmar Van der Putten, Nathalie Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation |
topic_facet |
Geology Diatoms Biogenic silica Isla de los Estados Late glacial-early Holocene Paleoenvironments |
description |
Isla de los Estados (54A degrees 45'S, 63A degrees 10'aEuro"64A degrees 46'W) lies east of the main island of Tierra del Fuego and is the southeastern-most point in Argentina. Because of its geographic position near the latitudes of the Southern Hemisphere Westerlies and the strong influence of the Antarctic Circumpolar Current (ACC), the area is suitable for paleoecological and paleoclimate research. The island is not far north of the Subantarctic Front, which limits the northern boundary of the ACC. Paleoenvironmental study in this geographic location can shed light on past changes in atmospheric and marine circulation patterns. Diatom analysis of the lower part of a sediment sequence from Laguna Cascada (54A degrees 45' 51.3''S, 64A degrees 20' 20.07''W) enabled inference of changing lake conditions between 16 and 11.1 cal ka BP. Between 16 and 14.4 cal ka BP fragilarioid diatom species, often a pioneer group, dominated the record. Their presence shows seasonally open-water conditions from the onset of sedimentation. In zone II (14.4-12.8 cal ka BP), the dominance of planktonic/tychoplanktonic Aulacoseira spp. might represent longer ice-free periods and windier conditions, which would have kept this heavy species suspended in the water column. This period corresponds to the Antarctic Cold Reversal, when the Southern Hemisphere Westerlies were possibly centered on the latitudes of Tierra del Fuego, resulting in windy and wet conditions. Zone III (12.8-11.1 cal ka BP) is dominated by benthic diatom taxa that are mainly associated with peat and wetland vegetation. This suggests that climate conditions had become milder and less windy, favoring aquatic productivity and terrestrial vegetation development. This change in environmental conditions may have been a consequence of the southward movement of the Southern Hemisphere Westerlies at the start of the Antarctic Holocene thermal optimum. |
format |
Article in Journal/Newspaper |
author |
Fernandez, Marilen Björck, Svante Wohlfarth, Barbara Maidana, Nora I. Unkel, Ingmar Van der Putten, Nathalie |
author_facet |
Fernandez, Marilen Björck, Svante Wohlfarth, Barbara Maidana, Nora I. Unkel, Ingmar Van der Putten, Nathalie |
author_sort |
Fernandez, Marilen |
title |
Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation |
title_short |
Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation |
title_full |
Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation |
title_fullStr |
Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation |
title_full_unstemmed |
Diatom assemblage changes in lacustrine sediments from Isla de los Estados, southernmost South America, in response to shifts in the southwesterly wind belt during the last deglaciation |
title_sort |
diatom assemblage changes in lacustrine sediments from isla de los estados, southernmost south america, in response to shifts in the southwesterly wind belt during the last deglaciation |
publisher |
Springer |
publishDate |
2013 |
url |
https://lup.lub.lu.se/record/4197940 https://doi.org/10.1007/s10933-013-9736-4 |
long_lat |
ENVELOPE(-45.619,-45.619,-60.708,-60.708) ENVELOPE(-38.220,-38.220,-54.007,-54.007) |
geographic |
Antarctic Argentina Changing Lake Main Island The Antarctic |
geographic_facet |
Antarctic Argentina Changing Lake Main Island The Antarctic |
genre |
Antarc* Antarctic Tierra del Fuego |
genre_facet |
Antarc* Antarctic Tierra del Fuego |
op_source |
Journal of Paleolimnology; 50(4), pp 433-446 (2013) ISSN: 0921-2728 |
op_relation |
https://lup.lub.lu.se/record/4197940 http://dx.doi.org/10.1007/s10933-013-9736-4 wos:000326622200002 scopus:84887317713 |
op_doi |
https://doi.org/10.1007/s10933-013-9736-4 |
container_title |
Journal of Paleolimnology |
container_volume |
50 |
container_issue |
4 |
container_start_page |
433 |
op_container_end_page |
446 |
_version_ |
1766249936314171392 |