Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction
Blue ice is found in areas of Antarctica where katabatic winds, focussed by steep surface slopes or by topography around nunataks, cause enhanced surface ablation. This process draws up deeper, older ice to the ice sheet surface, often bringing with it englacial sediment. Prevailing theories for dyn...
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Online Access: | https://orca.cardiff.ac.uk/id/eprint/147694/ https://doi.org/10.1016/j.qsa.2022.100051 https://orca.cardiff.ac.uk/id/eprint/147694/8/1-s2.0-S2666033422000041-main.pdf |
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:147694 2023-05-15T13:39:29+02:00 Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction Woodward, John Hein, Andrew S. Winter, Kate Westoby, Matthew J. Marrero, Shasta M. Dunning, Stuart A. Lim, Michael Rivera, Andrés Sugden, David E. 2022-04-30 application/pdf https://orca.cardiff.ac.uk/id/eprint/147694/ https://doi.org/10.1016/j.qsa.2022.100051 https://orca.cardiff.ac.uk/id/eprint/147694/8/1-s2.0-S2666033422000041-main.pdf en eng https://orca.cardiff.ac.uk/id/eprint/147694/8/1-s2.0-S2666033422000041-main.pdf Woodward, John, Hein, Andrew S., Winter, Kate, Westoby, Matthew J., Marrero, Shasta M. https://orca.cardiff.ac.uk/view/cardiffauthors/A2529897K.html orcid:0000-0003-2917-0292 orcid:0000-0003-2917-0292, Dunning, Stuart A., Lim, Michael, Rivera, Andrés and Sugden, David E. 2022. Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction. Quaternary Science Advances 6 , 100051. 10.1016/j.qsa.2022.100051 https://doi.org/10.1016/j.qsa.2022.100051 file https://orca.cardiff.ac.uk/147694/8/1-s2.0-S2666033422000041-main.pdf doi:10.1016/j.qsa.2022.100051 cc_by_nc_nd CC-BY-NC-ND Article PeerReviewed 2022 ftunivcardiff https://doi.org/10.1016/j.qsa.2022.100051 2022-11-10T23:42:42Z Blue ice is found in areas of Antarctica where katabatic winds, focussed by steep surface slopes or by topography around nunataks, cause enhanced surface ablation. This process draws up deeper, older ice to the ice sheet surface, often bringing with it englacial sediment. Prevailing theories for dynamically stable moraine surfaces in East Antarctica suggest that: (i) it is this material, once concentrated, that forms blue-ice moraines (BIM), (ii) that the moraine formation can be dated using cosmogenic isotope approaches, and that, (iii) since we expect an increase in exposure age moving away from the ice margin towards bedrock, dating across the moraine can be used to constrain ice-sheet history. To test this lateral accretion model for BIM formation we visited Patriot, Marble and Independence Hills in the southern Heritage Range, West Antarctica. Detailed field surveys of surface form, sediment and moraine dynamics were combined with geophysical surveys of the englacial structure of the moraines and cosmogenic nuclide analysis of surface clasts. Results suggest sediment is supplied mainly by basal entrainment, supplemented by debris-covered valley glaciers transferring material onto the ice sheet surface, direct deposition from rock-fall and slope processes from nunataks. We find that once sediment coalesces in BIM, significant reworking occurs through differential ablation, slope and periglacial processes. We bring these processes together in a conceptual model, concluding that many BIM in West Antarctica are dynamic and, whilst they persist through glacial cycles, they do not always neatly record ice sheet retreat patterns since linear distance from the ice margin does not always relate to increased clast exposure age. Understanding the dynamic processes involved in moraine formation is critical to the effective interpretation of the typically large scatter of cosmogenic nuclide exposure ages, opening a deep window into the million-year history of the West Antarctic Ice Sheet. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica Cardiff University: ORCA (Online Research @ Cardiff) Antarctic East Antarctica Heritage Range ENVELOPE(-82.000,-82.000,-80.000,-80.000) Independence Hills ENVELOPE(-81.250,-81.250,-80.417,-80.417) West Antarctic Ice Sheet West Antarctica Quaternary Science Advances 6 100051 |
institution |
Open Polar |
collection |
Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
description |
Blue ice is found in areas of Antarctica where katabatic winds, focussed by steep surface slopes or by topography around nunataks, cause enhanced surface ablation. This process draws up deeper, older ice to the ice sheet surface, often bringing with it englacial sediment. Prevailing theories for dynamically stable moraine surfaces in East Antarctica suggest that: (i) it is this material, once concentrated, that forms blue-ice moraines (BIM), (ii) that the moraine formation can be dated using cosmogenic isotope approaches, and that, (iii) since we expect an increase in exposure age moving away from the ice margin towards bedrock, dating across the moraine can be used to constrain ice-sheet history. To test this lateral accretion model for BIM formation we visited Patriot, Marble and Independence Hills in the southern Heritage Range, West Antarctica. Detailed field surveys of surface form, sediment and moraine dynamics were combined with geophysical surveys of the englacial structure of the moraines and cosmogenic nuclide analysis of surface clasts. Results suggest sediment is supplied mainly by basal entrainment, supplemented by debris-covered valley glaciers transferring material onto the ice sheet surface, direct deposition from rock-fall and slope processes from nunataks. We find that once sediment coalesces in BIM, significant reworking occurs through differential ablation, slope and periglacial processes. We bring these processes together in a conceptual model, concluding that many BIM in West Antarctica are dynamic and, whilst they persist through glacial cycles, they do not always neatly record ice sheet retreat patterns since linear distance from the ice margin does not always relate to increased clast exposure age. Understanding the dynamic processes involved in moraine formation is critical to the effective interpretation of the typically large scatter of cosmogenic nuclide exposure ages, opening a deep window into the million-year history of the West Antarctic Ice Sheet. |
format |
Article in Journal/Newspaper |
author |
Woodward, John Hein, Andrew S. Winter, Kate Westoby, Matthew J. Marrero, Shasta M. Dunning, Stuart A. Lim, Michael Rivera, Andrés Sugden, David E. |
spellingShingle |
Woodward, John Hein, Andrew S. Winter, Kate Westoby, Matthew J. Marrero, Shasta M. Dunning, Stuart A. Lim, Michael Rivera, Andrés Sugden, David E. Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction |
author_facet |
Woodward, John Hein, Andrew S. Winter, Kate Westoby, Matthew J. Marrero, Shasta M. Dunning, Stuart A. Lim, Michael Rivera, Andrés Sugden, David E. |
author_sort |
Woodward, John |
title |
Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction |
title_short |
Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction |
title_full |
Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction |
title_fullStr |
Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction |
title_full_unstemmed |
Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction |
title_sort |
blue-ice moraines formation in the heritage range, west antarctica: implications for ice sheet history and climate reconstruction |
publishDate |
2022 |
url |
https://orca.cardiff.ac.uk/id/eprint/147694/ https://doi.org/10.1016/j.qsa.2022.100051 https://orca.cardiff.ac.uk/id/eprint/147694/8/1-s2.0-S2666033422000041-main.pdf |
long_lat |
ENVELOPE(-82.000,-82.000,-80.000,-80.000) ENVELOPE(-81.250,-81.250,-80.417,-80.417) |
geographic |
Antarctic East Antarctica Heritage Range Independence Hills West Antarctic Ice Sheet West Antarctica |
geographic_facet |
Antarctic East Antarctica Heritage Range Independence Hills West Antarctic Ice Sheet West Antarctica |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/147694/8/1-s2.0-S2666033422000041-main.pdf Woodward, John, Hein, Andrew S., Winter, Kate, Westoby, Matthew J., Marrero, Shasta M. https://orca.cardiff.ac.uk/view/cardiffauthors/A2529897K.html orcid:0000-0003-2917-0292 orcid:0000-0003-2917-0292, Dunning, Stuart A., Lim, Michael, Rivera, Andrés and Sugden, David E. 2022. Blue-ice moraines formation in the Heritage Range, West Antarctica: Implications for ice sheet history and climate reconstruction. Quaternary Science Advances 6 , 100051. 10.1016/j.qsa.2022.100051 https://doi.org/10.1016/j.qsa.2022.100051 file https://orca.cardiff.ac.uk/147694/8/1-s2.0-S2666033422000041-main.pdf doi:10.1016/j.qsa.2022.100051 |
op_rights |
cc_by_nc_nd |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1016/j.qsa.2022.100051 |
container_title |
Quaternary Science Advances |
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6 |
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100051 |
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