Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers
Earth’s climate is undergoing dramatic warming that is unprecedented in at least the last ~2000 years. Outlets of the Antarctic ice sheet are experiencing dynamic thinning, terminus retreat and mass loss, however, we are currently unable to accurately predict their future response. The drivers and m...
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Victoria University of Wellington
2015
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ftvuwellington:oai:researcharchive.vuw.ac.nz:10063/8746 2023-08-15T12:38:38+02:00 Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers Jones, Richard Mackintosh, Andrew Norton, Kevin Golledge, Nicholas 2015-12-02T21:46:28Z http://researcharchive.vuw.ac.nz/handle/10063/8746 http://restrictedarchive.vuw.ac.nz/handle/123456789/9031 en_NZ eng Victoria University of Wellington http://researcharchive.vuw.ac.nz/handle/10063/8746 http://restrictedarchive.vuw.ac.nz/handle/123456789/9031 Author Retains All Rights Antarctica Ice sheet Glaciers Glaciology Palaeoclimate Numerical modelling Surface exposure dating Doctoral 2015 ftvuwellington 2023-07-25T17:29:39Z Earth’s climate is undergoing dramatic warming that is unprecedented in at least the last ~2000 years. Outlets of the Antarctic ice sheet are experiencing dynamic thinning, terminus retreat and mass loss, however, we are currently unable to accurately predict their future response. The drivers and mechanisms responsible for these observed changes can be better understood by studying the behaviour of outlet glaciers in the geological past. Here, I use cosmogenic nuclide surface-exposure dating and numerical glacier modelling to investigate the past configurations and dynamics of Transantarctic Mountain outlet glaciers, in the Ross Sea sector of Antarctica. Numerical modelling was first applied to understand the present-day and past behaviour of Skelton Glacier. A suite of sensitivity experiments reveal that Skelton Glacier is most susceptible to atmospheric temperature through its affect on basal sliding near the groundingline. Under past climates, large changes occurred in the lower reaches of the glacier, with basal sliding and bedrock erosion predicted in the overdeepened basins during both the Pliocene and Quaternary. Skelton Glacier was likely much shorter and thinner during Pliocene interglacials, with warm-based sliding that extended along most of its length. Informed by the glacier modelling, I applied surface-exposure dating to constrain past fluctuations in the geometry of Skelton Glacier. The lower reaches of the glacier were likely thicker at the Last Glacial Maximum (LGM), supporting the idea of buttressing by grounded ice in the Ross Sea during glacial periods. The glacier then thinned to near-modern surface elevations by ~5.8 ka before present (BP). Multiple isotope analysis (²⁶Al-¹⁰Be) and exposure-burial modelling indicates that Skelton Glacier has fluctuated between interglacial and glacial configurations probably at orbital frequencies since the Miocene. These data record a total of >10 Ma of exposure and 2.5 Ma of burial. An unexpected outcome is that the average cosmogenic production rate ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Ice Sheet Ross Sea Skelton Glacier Victoria University of Wellington: ResearchArchive Antarctic Ross Sea Skelton Glacier ENVELOPE(161.500,161.500,-78.583,-78.583) The Antarctic |
institution |
Open Polar |
collection |
Victoria University of Wellington: ResearchArchive |
op_collection_id |
ftvuwellington |
language |
English |
topic |
Antarctica Ice sheet Glaciers Glaciology Palaeoclimate Numerical modelling Surface exposure dating |
spellingShingle |
Antarctica Ice sheet Glaciers Glaciology Palaeoclimate Numerical modelling Surface exposure dating Jones, Richard Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers |
topic_facet |
Antarctica Ice sheet Glaciers Glaciology Palaeoclimate Numerical modelling Surface exposure dating |
description |
Earth’s climate is undergoing dramatic warming that is unprecedented in at least the last ~2000 years. Outlets of the Antarctic ice sheet are experiencing dynamic thinning, terminus retreat and mass loss, however, we are currently unable to accurately predict their future response. The drivers and mechanisms responsible for these observed changes can be better understood by studying the behaviour of outlet glaciers in the geological past. Here, I use cosmogenic nuclide surface-exposure dating and numerical glacier modelling to investigate the past configurations and dynamics of Transantarctic Mountain outlet glaciers, in the Ross Sea sector of Antarctica. Numerical modelling was first applied to understand the present-day and past behaviour of Skelton Glacier. A suite of sensitivity experiments reveal that Skelton Glacier is most susceptible to atmospheric temperature through its affect on basal sliding near the groundingline. Under past climates, large changes occurred in the lower reaches of the glacier, with basal sliding and bedrock erosion predicted in the overdeepened basins during both the Pliocene and Quaternary. Skelton Glacier was likely much shorter and thinner during Pliocene interglacials, with warm-based sliding that extended along most of its length. Informed by the glacier modelling, I applied surface-exposure dating to constrain past fluctuations in the geometry of Skelton Glacier. The lower reaches of the glacier were likely thicker at the Last Glacial Maximum (LGM), supporting the idea of buttressing by grounded ice in the Ross Sea during glacial periods. The glacier then thinned to near-modern surface elevations by ~5.8 ka before present (BP). Multiple isotope analysis (²⁶Al-¹⁰Be) and exposure-burial modelling indicates that Skelton Glacier has fluctuated between interglacial and glacial configurations probably at orbital frequencies since the Miocene. These data record a total of >10 Ma of exposure and 2.5 Ma of burial. An unexpected outcome is that the average cosmogenic production rate ... |
author2 |
Mackintosh, Andrew Norton, Kevin Golledge, Nicholas |
format |
Doctoral or Postdoctoral Thesis |
author |
Jones, Richard |
author_facet |
Jones, Richard |
author_sort |
Jones, Richard |
title |
Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers |
title_short |
Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers |
title_full |
Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers |
title_fullStr |
Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers |
title_full_unstemmed |
Late Cenozoic behaviour of two Transantarctic Mountain outlet glaciers |
title_sort |
late cenozoic behaviour of two transantarctic mountain outlet glaciers |
publisher |
Victoria University of Wellington |
publishDate |
2015 |
url |
http://researcharchive.vuw.ac.nz/handle/10063/8746 http://restrictedarchive.vuw.ac.nz/handle/123456789/9031 |
long_lat |
ENVELOPE(161.500,161.500,-78.583,-78.583) |
geographic |
Antarctic Ross Sea Skelton Glacier The Antarctic |
geographic_facet |
Antarctic Ross Sea Skelton Glacier The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea Skelton Glacier |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea Skelton Glacier |
op_relation |
http://researcharchive.vuw.ac.nz/handle/10063/8746 http://restrictedarchive.vuw.ac.nz/handle/123456789/9031 |
op_rights |
Author Retains All Rights |
_version_ |
1774300012747948032 |