Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods
While measurements of ice-sheet surface elevation change are increasingly used to assess mass change, the processes that control the elevation fluctuations not related to ice-flow dynamics (e.g. firn compaction and accumulation) remain difficult to measure. Here we use radar data from the Thwaites G...
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International Glaciological Society
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Online Access: | http://hdl.handle.net/1808/22196 https://doi.org/10.3189/2015AoG70A203 |
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ftunivkansas:oai:kuscholarworks.ku.edu:1808/22196 2023-05-15T13:29:38+02:00 Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods Medley, B. Ligtenberg, S. R. M. Joughin, Ian R. van den Broeke, Michiel R. Gogineni, Sivaprasad Nowicki, S. 2016-12-13T17:10:02Z http://hdl.handle.net/1808/22196 https://doi.org/10.3189/2015AoG70A203 unknown International Glaciological Society Medley, B., Ligtenberg, S., Joughin, I., Broeke, M. V., Gogineni, S., & Nowicki, S. (2015). Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods. Annals of Glaciology, 56(70), 155-166. doi:10.3189/2015aog70a203 http://hdl.handle.net/1808/22196 doi:10.3189/2015AoG70A203 openAccess Accumulation Ground-Penetrating Radar Polar Firn Article 2016 ftunivkansas https://doi.org/10.3189/2015AoG70A203 2022-08-26T13:20:07Z While measurements of ice-sheet surface elevation change are increasingly used to assess mass change, the processes that control the elevation fluctuations not related to ice-flow dynamics (e.g. firn compaction and accumulation) remain difficult to measure. Here we use radar data from the Thwaites Glacier (West Antarctica) catchment to measure the rate of thickness change between horizons of constant age over different time intervals: 2009–10, 2010–11 and 2009–11. The average compaction rate to ∼25 m depth is 0.33 m a–1, with largest compaction rates near the surface. Our measurements indicate that the accumulation rate controls much of the spatio-temporal variations in the compaction rate while the role of temperature is unclear due to a lack of measurements. Based on a semi-empirical, steady-state densification model, we find that surveying older firn horizons minimizes the potential bias resulting from the variable depth of the constant age horizon. Our results suggest that the spatiotemporal variations in the firn compaction rate are an important consideration when converting surface elevation change to ice mass change. Compaction rates varied by up to 0.12 m a–1 over distances <6 km and were on average >20% larger during the 2010–11 interval than during 2009–10. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctic Antarctica Ice Sheet Thwaites Glacier West Antarctica The University of Kansas: KU ScholarWorks Antarctic Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica Annals of Glaciology 56 70 155 166 |
institution |
Open Polar |
collection |
The University of Kansas: KU ScholarWorks |
op_collection_id |
ftunivkansas |
language |
unknown |
topic |
Accumulation Ground-Penetrating Radar Polar Firn |
spellingShingle |
Accumulation Ground-Penetrating Radar Polar Firn Medley, B. Ligtenberg, S. R. M. Joughin, Ian R. van den Broeke, Michiel R. Gogineni, Sivaprasad Nowicki, S. Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods |
topic_facet |
Accumulation Ground-Penetrating Radar Polar Firn |
description |
While measurements of ice-sheet surface elevation change are increasingly used to assess mass change, the processes that control the elevation fluctuations not related to ice-flow dynamics (e.g. firn compaction and accumulation) remain difficult to measure. Here we use radar data from the Thwaites Glacier (West Antarctica) catchment to measure the rate of thickness change between horizons of constant age over different time intervals: 2009–10, 2010–11 and 2009–11. The average compaction rate to ∼25 m depth is 0.33 m a–1, with largest compaction rates near the surface. Our measurements indicate that the accumulation rate controls much of the spatio-temporal variations in the compaction rate while the role of temperature is unclear due to a lack of measurements. Based on a semi-empirical, steady-state densification model, we find that surveying older firn horizons minimizes the potential bias resulting from the variable depth of the constant age horizon. Our results suggest that the spatiotemporal variations in the firn compaction rate are an important consideration when converting surface elevation change to ice mass change. Compaction rates varied by up to 0.12 m a–1 over distances <6 km and were on average >20% larger during the 2010–11 interval than during 2009–10. |
format |
Article in Journal/Newspaper |
author |
Medley, B. Ligtenberg, S. R. M. Joughin, Ian R. van den Broeke, Michiel R. Gogineni, Sivaprasad Nowicki, S. |
author_facet |
Medley, B. Ligtenberg, S. R. M. Joughin, Ian R. van den Broeke, Michiel R. Gogineni, Sivaprasad Nowicki, S. |
author_sort |
Medley, B. |
title |
Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods |
title_short |
Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods |
title_full |
Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods |
title_fullStr |
Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods |
title_full_unstemmed |
Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods |
title_sort |
antarctic firn compaction rates from repeat-track airborne radar data: i. methods |
publisher |
International Glaciological Society |
publishDate |
2016 |
url |
http://hdl.handle.net/1808/22196 https://doi.org/10.3189/2015AoG70A203 |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Antarctic Thwaites Glacier West Antarctica |
geographic_facet |
Antarctic Thwaites Glacier West Antarctica |
genre |
Annals of Glaciology Antarc* Antarctic Antarctica Ice Sheet Thwaites Glacier West Antarctica |
genre_facet |
Annals of Glaciology Antarc* Antarctic Antarctica Ice Sheet Thwaites Glacier West Antarctica |
op_relation |
Medley, B., Ligtenberg, S., Joughin, I., Broeke, M. V., Gogineni, S., & Nowicki, S. (2015). Antarctic firn compaction rates from repeat-track airborne radar data: I. Methods. Annals of Glaciology, 56(70), 155-166. doi:10.3189/2015aog70a203 http://hdl.handle.net/1808/22196 doi:10.3189/2015AoG70A203 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.3189/2015AoG70A203 |
container_title |
Annals of Glaciology |
container_volume |
56 |
container_issue |
70 |
container_start_page |
155 |
op_container_end_page |
166 |
_version_ |
1766001628625764352 |