Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica
The geomorphic record indicates that alpine glaciers in the McMurdo Dry Valleys of southern Victoria Land, Antarctica appear to advance during interglacial periods in response to ice-free conditions in the Ross Sea. Few records of these advances are preserved and/or subaerially exposed, complicating...
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ftcopernicus:oai:publications.copernicus.org:tcd77102 2023-05-15T13:35:06+02:00 Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica Winsor, Kelsey Swanger, Kate M. Babcock, Esther Valletta, Rachel D. Dickson, James L. 2019-06-18 application/pdf https://doi.org/10.5194/tc-2019-135 https://www.the-cryosphere-discuss.net/tc-2019-135/ eng eng doi:10.5194/tc-2019-135 https://www.the-cryosphere-discuss.net/tc-2019-135/ eISSN: 1994-0424 Text 2019 ftcopernicus https://doi.org/10.5194/tc-2019-135 2019-12-24T09:49:01Z The geomorphic record indicates that alpine glaciers in the McMurdo Dry Valleys of southern Victoria Land, Antarctica appear to advance during interglacial periods in response to ice-free conditions in the Ross Sea. Few records of these advances are preserved and/or subaerially exposed, complicating the interpretations of regional glacier response to climate changes. Here, we present geophysical and geochemical analyses of a rock glacier that originates from icefalls fed by alpine Doran Glacier in central Taylor Valley. The rock glacier exhibits a trend of increased weathering of granitic clasts via ventifaction and grussification down-flow. Meltwater ponds on the rock glacier exhibit variable salinity that ranges from freshwater to higher than seawater, with the highest salinity pond near the rock glacier toe. Ground-penetrating radar analyses reveal the feature to possess a primarily clean ice interior, with layers of englacial debris. Stable isotopic data from three ice cores support a glacial origin for the ice within the rock glacier. These data suggest that the current morphology of the rock glacier is the result of multiple events of increased ice contribution caused by advances of Doran Glacier, which is the main source of the ice that cores the rock glacier. We therefore demonstrate the potential of ice-cored rock glaciers to record multiple advances and retreats of Dry Valley glaciers, permitting the interpretation of glacial responses to Pleistocene and Holocene climate change even where direct records are not present. Text Antarc* Antarctica McMurdo Dry Valleys Ross Sea Victoria Land Copernicus Publications: E-Journals Doran Glacier ENVELOPE(162.667,162.667,-77.717,-77.717) McMurdo Dry Valleys Ross Sea Taylor Valley ENVELOPE(163.000,163.000,-77.617,-77.617) Victoria Land |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The geomorphic record indicates that alpine glaciers in the McMurdo Dry Valleys of southern Victoria Land, Antarctica appear to advance during interglacial periods in response to ice-free conditions in the Ross Sea. Few records of these advances are preserved and/or subaerially exposed, complicating the interpretations of regional glacier response to climate changes. Here, we present geophysical and geochemical analyses of a rock glacier that originates from icefalls fed by alpine Doran Glacier in central Taylor Valley. The rock glacier exhibits a trend of increased weathering of granitic clasts via ventifaction and grussification down-flow. Meltwater ponds on the rock glacier exhibit variable salinity that ranges from freshwater to higher than seawater, with the highest salinity pond near the rock glacier toe. Ground-penetrating radar analyses reveal the feature to possess a primarily clean ice interior, with layers of englacial debris. Stable isotopic data from three ice cores support a glacial origin for the ice within the rock glacier. These data suggest that the current morphology of the rock glacier is the result of multiple events of increased ice contribution caused by advances of Doran Glacier, which is the main source of the ice that cores the rock glacier. We therefore demonstrate the potential of ice-cored rock glaciers to record multiple advances and retreats of Dry Valley glaciers, permitting the interpretation of glacial responses to Pleistocene and Holocene climate change even where direct records are not present. |
format |
Text |
author |
Winsor, Kelsey Swanger, Kate M. Babcock, Esther Valletta, Rachel D. Dickson, James L. |
spellingShingle |
Winsor, Kelsey Swanger, Kate M. Babcock, Esther Valletta, Rachel D. Dickson, James L. Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica |
author_facet |
Winsor, Kelsey Swanger, Kate M. Babcock, Esther Valletta, Rachel D. Dickson, James L. |
author_sort |
Winsor, Kelsey |
title |
Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica |
title_short |
Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica |
title_full |
Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica |
title_fullStr |
Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica |
title_full_unstemmed |
Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica |
title_sort |
rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in taylor valley, antarctica |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-2019-135 https://www.the-cryosphere-discuss.net/tc-2019-135/ |
long_lat |
ENVELOPE(162.667,162.667,-77.717,-77.717) ENVELOPE(163.000,163.000,-77.617,-77.617) |
geographic |
Doran Glacier McMurdo Dry Valleys Ross Sea Taylor Valley Victoria Land |
geographic_facet |
Doran Glacier McMurdo Dry Valleys Ross Sea Taylor Valley Victoria Land |
genre |
Antarc* Antarctica McMurdo Dry Valleys Ross Sea Victoria Land |
genre_facet |
Antarc* Antarctica McMurdo Dry Valleys Ross Sea Victoria Land |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2019-135 https://www.the-cryosphere-discuss.net/tc-2019-135/ |
op_doi |
https://doi.org/10.5194/tc-2019-135 |
_version_ |
1766060847290908672 |