Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone
Ocean‐driven melting of ice shelves is a primary mechanism for ice loss from Antarctica. However, due to the difficulty in accessing the sub‐ice shelf ocean cavity, the relationship between ice shelf melting and ocean conditions is poorly understood, particularly near the grounding zone, where the i...
Published in: | Journal of Geophysical Research: Oceans |
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Online Access: | https://doi.org/10.1029/2018JC013987 http://ecite.utas.edu.au/128889 |
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ftunivtasecite:oai:ecite.utas.edu.au:128889 2023-05-15T13:42:40+02:00 Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone Begeman, CB Tulaczyk, SM Marsh, OJ Mikucki, JA Stanton, TP Hodson, TO Siegfried, MR Powell, RD Christianson, K King, MA 2018 application/pdf https://doi.org/10.1029/2018JC013987 http://ecite.utas.edu.au/128889 en eng Wiley-Blackwell Publishing http://ecite.utas.edu.au/128889/1/Begeman_et_al-2018-Journal_of_Geophysical_Research_Oceans.pdf http://dx.doi.org/10.1029/2018JC013987 Begeman, CB and Tulaczyk, SM and Marsh, OJ and Mikucki, JA and Stanton, TP and Hodson, TO and Siegfried, MR and Powell, RD and Christianson, K and King, MA, Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone, Journal of Geophysical Research: Oceans, 123, (10) pp. 7438-7452. ISSN 2169-9275 (2018) [Refereed Article] http://ecite.utas.edu.au/128889 Engineering Geomatic engineering Satellite-based positioning Refereed Article PeerReviewed 2018 ftunivtasecite https://doi.org/10.1029/2018JC013987 2022-08-29T22:17:26Z Ocean‐driven melting of ice shelves is a primary mechanism for ice loss from Antarctica. However, due to the difficulty in accessing the sub‐ice shelf ocean cavity, the relationship between ice shelf melting and ocean conditions is poorly understood, particularly near the grounding zone, where the ice transitions from grounded to floating. We present the first borehole oceanographic observations from the grounding zone of the Ross Ice Shelf, Antarctica's largest ice shelf by area. Contrary to predictions that tidal currents near grounding zones mix the water column, we found that Ross Ice Shelf waters were vertically stratified. Current velocities at middepth in the ocean cavity did not change significantly over measurement periods at two different parts of the tidal cycle. The observed stratification resulted in low melt rates near this portion of the grounding zone, inferred from phase‐sensitive radar observations. These melt rates were generally <10 cm/year, which is lower than average for the Ross Ice Shelf (∼20 cm/year). Melt rates may be higher at portions of the grounding zone that experience higher subglacial discharge or stronger tidal mixing. Stratification in the cavity at the borehole site was prone to diffusive convection as a result of ice shelf melting. Since diffusive convection influences vertical heat and salt fluxes differently than shear‐driven turbulence, this process may affect ice shelf melting and merits further consideration in ocean models of sub‐ice shelf circulation. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Ice Shelves Ross Ice Shelf eCite UTAS (University of Tasmania) Ross Ice Shelf Journal of Geophysical Research: Oceans 123 10 7438 7452 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Engineering Geomatic engineering Satellite-based positioning |
spellingShingle |
Engineering Geomatic engineering Satellite-based positioning Begeman, CB Tulaczyk, SM Marsh, OJ Mikucki, JA Stanton, TP Hodson, TO Siegfried, MR Powell, RD Christianson, K King, MA Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone |
topic_facet |
Engineering Geomatic engineering Satellite-based positioning |
description |
Ocean‐driven melting of ice shelves is a primary mechanism for ice loss from Antarctica. However, due to the difficulty in accessing the sub‐ice shelf ocean cavity, the relationship between ice shelf melting and ocean conditions is poorly understood, particularly near the grounding zone, where the ice transitions from grounded to floating. We present the first borehole oceanographic observations from the grounding zone of the Ross Ice Shelf, Antarctica's largest ice shelf by area. Contrary to predictions that tidal currents near grounding zones mix the water column, we found that Ross Ice Shelf waters were vertically stratified. Current velocities at middepth in the ocean cavity did not change significantly over measurement periods at two different parts of the tidal cycle. The observed stratification resulted in low melt rates near this portion of the grounding zone, inferred from phase‐sensitive radar observations. These melt rates were generally <10 cm/year, which is lower than average for the Ross Ice Shelf (∼20 cm/year). Melt rates may be higher at portions of the grounding zone that experience higher subglacial discharge or stronger tidal mixing. Stratification in the cavity at the borehole site was prone to diffusive convection as a result of ice shelf melting. Since diffusive convection influences vertical heat and salt fluxes differently than shear‐driven turbulence, this process may affect ice shelf melting and merits further consideration in ocean models of sub‐ice shelf circulation. |
format |
Article in Journal/Newspaper |
author |
Begeman, CB Tulaczyk, SM Marsh, OJ Mikucki, JA Stanton, TP Hodson, TO Siegfried, MR Powell, RD Christianson, K King, MA |
author_facet |
Begeman, CB Tulaczyk, SM Marsh, OJ Mikucki, JA Stanton, TP Hodson, TO Siegfried, MR Powell, RD Christianson, K King, MA |
author_sort |
Begeman, CB |
title |
Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone |
title_short |
Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone |
title_full |
Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone |
title_fullStr |
Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone |
title_full_unstemmed |
Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone |
title_sort |
ocean stratification and low melt rates at the ross ice shelf grounding zone |
publisher |
Wiley-Blackwell Publishing |
publishDate |
2018 |
url |
https://doi.org/10.1029/2018JC013987 http://ecite.utas.edu.au/128889 |
geographic |
Ross Ice Shelf |
geographic_facet |
Ross Ice Shelf |
genre |
Antarc* Antarctica Ice Shelf Ice Shelves Ross Ice Shelf |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves Ross Ice Shelf |
op_relation |
http://ecite.utas.edu.au/128889/1/Begeman_et_al-2018-Journal_of_Geophysical_Research_Oceans.pdf http://dx.doi.org/10.1029/2018JC013987 Begeman, CB and Tulaczyk, SM and Marsh, OJ and Mikucki, JA and Stanton, TP and Hodson, TO and Siegfried, MR and Powell, RD and Christianson, K and King, MA, Ocean stratification and low melt rates at the Ross Ice Shelf grounding zone, Journal of Geophysical Research: Oceans, 123, (10) pp. 7438-7452. ISSN 2169-9275 (2018) [Refereed Article] http://ecite.utas.edu.au/128889 |
op_doi |
https://doi.org/10.1029/2018JC013987 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
123 |
container_issue |
10 |
container_start_page |
7438 |
op_container_end_page |
7452 |
_version_ |
1766171060498071552 |