The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand
Glacier advances in the southern mid-latitudes during the last glacial cycle (ca. 110-10 ka) were controlled by changes in temperature and precipitation linked to several important ocean-climate systems. As such, the timing of glacial advance and retreat can yield important insights into the mechani...
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2016
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ftunivqespace:oai:espace.library.uq.edu.au:UQ:406945 2023-05-15T13:51:35+02:00 The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand Darvill, Christopher M. Bentley, Michael J. Stokes, Chris R. Shulmeister, James 2016-10-01 https://espace.library.uq.edu.au/view/UQ:406945 eng eng Pergamon Press doi:10.1016/j.quascirev.2016.07.024 issn:0277-3791 issn:1873-457X orcid:0000-0001-5863-9462 NE/j500215/1 1079590 Last glacial cycle Patagonia New Zealand Cosmogenic nuclide exposure dating Glacial advances 1105 Ecology Evolution Behavior and Systematics 1204 Archaeology 1907 Geology 2306 Global and Planetary Change 3302 Archaeology Journal Article 2016 ftunivqespace https://doi.org/10.1016/j.quascirev.2016.07.024 2020-12-08T00:33:11Z Glacier advances in the southern mid-latitudes during the last glacial cycle (ca. 110-10 ka) were controlled by changes in temperature and precipitation linked to several important ocean-climate systems. As such, the timing of glacial advance and retreat can yield important insights into the mechanisms of Southern Hemisphere climate change. This is particularly important given that several recent studies have demonstrated significant glacial advances prior to the global Last Glacial Maximum (gLGM) in Patagonia and New Zealand, the cause of which are uncertain. The recent increase in chronological studies in these regions offers the opportunity to compare regional trends in glacial activity. Here, we compile the first consistent Be-10 exposure-dating chronologies for Patagonia and New Zealand to highlight the broad pattern of mid-latitude glacial activity over the last glacial cycle. Our results show that advances or still stands culminated at 26-27 ka, 18-19 ka and 13-14 ka in both Patagonia and New Zealand and were broadly synchronous, but with an offset between regions of up to 900 years that cannot be explained by age calculation or physically plausible erosion differences. Furthermore, there is evidence in both regions for glacial advances culminating from at least 45 ka, during the latter half of Marine Isotope Stage (MIS) 3. Glacial activity prior to the gLGM differed from the large Northern Hemisphere ice sheets, likely due to favourable Southern Hemisphere conditions during late MIS 3: summer insolation reached a minimum, seasonality was reduced, winter duration was increasing, and sea ice had expanded significantly, inducing stratification of the ocean and triggering northward migration of oceanic fronts and the Southern Westerly Winds. Glacial advances in Patagonia and New Zealand during the gLGM were probably primed by underlying orbital parameters. However, the precise timing is likely to have been intrinsically linked to migration of the coupled ocean-atmosphere system, which may account for the small offset between Patagonia and New Zealand due to differences in oceanic frontal migration. During deglaciation, advances or still stands occurred in both regions during the southern Antarctic Cold Reversal (ca. 14.5-12.9 ka) rather than the northern Younger Dryas (ca. 12.9-11.7 ka). Our findings suggest that major rearrangements of the Southern Hemisphere climate system occurred at various times during the last glacial cycle, with associated impacts on the position and intensity of the Southern Westerly Winds and oceanic fronts, as well as wind-driven upwelling and degassing of the deep Southern Ocean. Thus, reconstructing the timing of glacial advance/retreat using our compilation is a powerful way to understand the mechanisms of past interhemispheric climate change. (C) 2016 Elsevier Ltd. All rights reserved. Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean The University of Queensland: UQ eSpace Antarctic New Zealand Patagonia Southern Ocean Quaternary Science Reviews 149 200 214 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
English |
topic |
Last glacial cycle Patagonia New Zealand Cosmogenic nuclide exposure dating Glacial advances 1105 Ecology Evolution Behavior and Systematics 1204 Archaeology 1907 Geology 2306 Global and Planetary Change 3302 Archaeology |
spellingShingle |
Last glacial cycle Patagonia New Zealand Cosmogenic nuclide exposure dating Glacial advances 1105 Ecology Evolution Behavior and Systematics 1204 Archaeology 1907 Geology 2306 Global and Planetary Change 3302 Archaeology Darvill, Christopher M. Bentley, Michael J. Stokes, Chris R. Shulmeister, James The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand |
topic_facet |
Last glacial cycle Patagonia New Zealand Cosmogenic nuclide exposure dating Glacial advances 1105 Ecology Evolution Behavior and Systematics 1204 Archaeology 1907 Geology 2306 Global and Planetary Change 3302 Archaeology |
description |
Glacier advances in the southern mid-latitudes during the last glacial cycle (ca. 110-10 ka) were controlled by changes in temperature and precipitation linked to several important ocean-climate systems. As such, the timing of glacial advance and retreat can yield important insights into the mechanisms of Southern Hemisphere climate change. This is particularly important given that several recent studies have demonstrated significant glacial advances prior to the global Last Glacial Maximum (gLGM) in Patagonia and New Zealand, the cause of which are uncertain. The recent increase in chronological studies in these regions offers the opportunity to compare regional trends in glacial activity. Here, we compile the first consistent Be-10 exposure-dating chronologies for Patagonia and New Zealand to highlight the broad pattern of mid-latitude glacial activity over the last glacial cycle. Our results show that advances or still stands culminated at 26-27 ka, 18-19 ka and 13-14 ka in both Patagonia and New Zealand and were broadly synchronous, but with an offset between regions of up to 900 years that cannot be explained by age calculation or physically plausible erosion differences. Furthermore, there is evidence in both regions for glacial advances culminating from at least 45 ka, during the latter half of Marine Isotope Stage (MIS) 3. Glacial activity prior to the gLGM differed from the large Northern Hemisphere ice sheets, likely due to favourable Southern Hemisphere conditions during late MIS 3: summer insolation reached a minimum, seasonality was reduced, winter duration was increasing, and sea ice had expanded significantly, inducing stratification of the ocean and triggering northward migration of oceanic fronts and the Southern Westerly Winds. Glacial advances in Patagonia and New Zealand during the gLGM were probably primed by underlying orbital parameters. However, the precise timing is likely to have been intrinsically linked to migration of the coupled ocean-atmosphere system, which may account for the small offset between Patagonia and New Zealand due to differences in oceanic frontal migration. During deglaciation, advances or still stands occurred in both regions during the southern Antarctic Cold Reversal (ca. 14.5-12.9 ka) rather than the northern Younger Dryas (ca. 12.9-11.7 ka). Our findings suggest that major rearrangements of the Southern Hemisphere climate system occurred at various times during the last glacial cycle, with associated impacts on the position and intensity of the Southern Westerly Winds and oceanic fronts, as well as wind-driven upwelling and degassing of the deep Southern Ocean. Thus, reconstructing the timing of glacial advance/retreat using our compilation is a powerful way to understand the mechanisms of past interhemispheric climate change. (C) 2016 Elsevier Ltd. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Darvill, Christopher M. Bentley, Michael J. Stokes, Chris R. Shulmeister, James |
author_facet |
Darvill, Christopher M. Bentley, Michael J. Stokes, Chris R. Shulmeister, James |
author_sort |
Darvill, Christopher M. |
title |
The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand |
title_short |
The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand |
title_full |
The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand |
title_fullStr |
The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand |
title_full_unstemmed |
The timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from Patagonia and New Zealand |
title_sort |
timing and cause of glacial advances in the southern mid-latitudes during the last glacial cycle based on a synthesis of exposure ages from patagonia and new zealand |
publisher |
Pergamon Press |
publishDate |
2016 |
url |
https://espace.library.uq.edu.au/view/UQ:406945 |
geographic |
Antarctic New Zealand Patagonia Southern Ocean |
geographic_facet |
Antarctic New Zealand Patagonia Southern Ocean |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_relation |
doi:10.1016/j.quascirev.2016.07.024 issn:0277-3791 issn:1873-457X orcid:0000-0001-5863-9462 NE/j500215/1 1079590 |
op_doi |
https://doi.org/10.1016/j.quascirev.2016.07.024 |
container_title |
Quaternary Science Reviews |
container_volume |
149 |
container_start_page |
200 |
op_container_end_page |
214 |
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1766255547385905152 |