Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection
Tidewater glacier calving provides the most direct mechanism of ice transfer from land to the ocean. However, the physical melt processes influencing calving remain challenging to constrain. In this study we focus on calving rates at Kongsbreen, a tidewater glacier in Svalbard, due to three mechanis...
Published in: | Journal of Geophysical Research: Earth Surface |
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2018
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Online Access: | https://pure.uhi.ac.uk/en/publications/f4334ad6-a66e-4b76-9e21-96fd5bd06b79 https://doi.org/10.1029/2017JF004520 https://pureadmin.uhi.ac.uk/ws/files/3658981/Schild_et_al_2018_Journal_of_Geophysical_Research_Earth_Surface.pdf |
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ftuhipublicatio:oai:pure.atira.dk:publications/f4334ad6-a66e-4b76-9e21-96fd5bd06b79 2024-05-19T07:40:48+00:00 Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection Schild, K Renshaw, C Benn, Douglas I Luckman, Adrian Hawley, RL How, P Trusel, L Cottier, Finlo Pramanik, A Hulton, NRJ 2018-09-15 application/pdf https://pure.uhi.ac.uk/en/publications/f4334ad6-a66e-4b76-9e21-96fd5bd06b79 https://doi.org/10.1029/2017JF004520 https://pureadmin.uhi.ac.uk/ws/files/3658981/Schild_et_al_2018_Journal_of_Geophysical_Research_Earth_Surface.pdf eng eng https://pure.uhi.ac.uk/en/publications/f4334ad6-a66e-4b76-9e21-96fd5bd06b79 info:eu-repo/semantics/openAccess Schild , K , Renshaw , C , Benn , D I , Luckman , A , Hawley , RL , How , P , Trusel , L , Cottier , F , Pramanik , A & Hulton , NRJ 2018 , ' Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection ' , Journal of Geophysical Research: Earth Surface , vol. 123 , no. 9 , pp. 2189-2204 . https://doi.org/10.1029/2017JF004520 calving tidewater glacier iceberg submarine melt time-lapse camera Svalbard article 2018 ftuhipublicatio https://doi.org/10.1029/2017JF004520 2024-04-25T00:21:46Z Tidewater glacier calving provides the most direct mechanism of ice transfer from land to the ocean. However, the physical melt processes influencing calving remain challenging to constrain. In this study we focus on calving rates at Kongsbreen, a tidewater glacier in Svalbard, due to three mechanisms of submarine melt: 1) free convection, 2) horizontal fjord circulation, and 3) meltwater discharge. To calculate an overall calving rate, we measure glacier velocity and terminus change using Sentinel imagery. We calculate free convection, fjord circulation, and meltwater discharge calving using mooring data for mid‐fjord ocean temperature (30–80 m depth), reanalysis results for meltwater runoff, and georectified time‐lapse imagery to track icebergs and infer surface circulation. Results show the total glacier calving rate is highly correlated with ocean temperature during the 2016 melt season. When runoff was present, we found that subglacial discharge accounted for calving rates an order of magnitude greater than the maximum calving rates assigned to the other two melting mechanisms combined. Further, subglacial discharge at Kongsbreen was more efficient in inducing calving later in the season than earlier in the season, implying that the increase in ocean temperatures, the timing of meltwater discharge within a melt season, and/or the development of discrete meltwater exit channels are critical components to calving rates. As the recent atmospheric warming trend and subsequent increase in meltwater discharge is expected to continue, it is essential to understand the processes contributing to an increase in glacier calving and incorporate these processes into predictive models. Article in Journal/Newspaper glacier Svalbard Tidewater University of the Highlands and Islands: Research Database of UHI Journal of Geophysical Research: Earth Surface 123 9 2189 2204 |
institution |
Open Polar |
collection |
University of the Highlands and Islands: Research Database of UHI |
op_collection_id |
ftuhipublicatio |
language |
English |
topic |
calving tidewater glacier iceberg submarine melt time-lapse camera Svalbard |
spellingShingle |
calving tidewater glacier iceberg submarine melt time-lapse camera Svalbard Schild, K Renshaw, C Benn, Douglas I Luckman, Adrian Hawley, RL How, P Trusel, L Cottier, Finlo Pramanik, A Hulton, NRJ Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection |
topic_facet |
calving tidewater glacier iceberg submarine melt time-lapse camera Svalbard |
description |
Tidewater glacier calving provides the most direct mechanism of ice transfer from land to the ocean. However, the physical melt processes influencing calving remain challenging to constrain. In this study we focus on calving rates at Kongsbreen, a tidewater glacier in Svalbard, due to three mechanisms of submarine melt: 1) free convection, 2) horizontal fjord circulation, and 3) meltwater discharge. To calculate an overall calving rate, we measure glacier velocity and terminus change using Sentinel imagery. We calculate free convection, fjord circulation, and meltwater discharge calving using mooring data for mid‐fjord ocean temperature (30–80 m depth), reanalysis results for meltwater runoff, and georectified time‐lapse imagery to track icebergs and infer surface circulation. Results show the total glacier calving rate is highly correlated with ocean temperature during the 2016 melt season. When runoff was present, we found that subglacial discharge accounted for calving rates an order of magnitude greater than the maximum calving rates assigned to the other two melting mechanisms combined. Further, subglacial discharge at Kongsbreen was more efficient in inducing calving later in the season than earlier in the season, implying that the increase in ocean temperatures, the timing of meltwater discharge within a melt season, and/or the development of discrete meltwater exit channels are critical components to calving rates. As the recent atmospheric warming trend and subsequent increase in meltwater discharge is expected to continue, it is essential to understand the processes contributing to an increase in glacier calving and incorporate these processes into predictive models. |
format |
Article in Journal/Newspaper |
author |
Schild, K Renshaw, C Benn, Douglas I Luckman, Adrian Hawley, RL How, P Trusel, L Cottier, Finlo Pramanik, A Hulton, NRJ |
author_facet |
Schild, K Renshaw, C Benn, Douglas I Luckman, Adrian Hawley, RL How, P Trusel, L Cottier, Finlo Pramanik, A Hulton, NRJ |
author_sort |
Schild, K |
title |
Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection |
title_short |
Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection |
title_full |
Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection |
title_fullStr |
Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection |
title_full_unstemmed |
Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection |
title_sort |
glacier calving rates due to subglacial discharge, fjord circulation, and free convection |
publishDate |
2018 |
url |
https://pure.uhi.ac.uk/en/publications/f4334ad6-a66e-4b76-9e21-96fd5bd06b79 https://doi.org/10.1029/2017JF004520 https://pureadmin.uhi.ac.uk/ws/files/3658981/Schild_et_al_2018_Journal_of_Geophysical_Research_Earth_Surface.pdf |
genre |
glacier Svalbard Tidewater |
genre_facet |
glacier Svalbard Tidewater |
op_source |
Schild , K , Renshaw , C , Benn , D I , Luckman , A , Hawley , RL , How , P , Trusel , L , Cottier , F , Pramanik , A & Hulton , NRJ 2018 , ' Glacier Calving Rates due to Subglacial Discharge, Fjord Circulation, and Free Convection ' , Journal of Geophysical Research: Earth Surface , vol. 123 , no. 9 , pp. 2189-2204 . https://doi.org/10.1029/2017JF004520 |
op_relation |
https://pure.uhi.ac.uk/en/publications/f4334ad6-a66e-4b76-9e21-96fd5bd06b79 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2017JF004520 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
123 |
container_issue |
9 |
container_start_page |
2189 |
op_container_end_page |
2204 |
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1799480382347804672 |