Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes
Folgefonna consists of three ice caps which are rapidly retreating in response to warmer temperatures. The melting of Folgefonna has implications for meltwater drainage and hydropower production, as well as the potential for geohazards and impacts to tourism, the communities and infrastructures surr...
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Online Access: | https://hdl.handle.net/11250/3024559 https://doi.org/10.3389/feart.2022.886361 |
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ftunivbergen:oai:bora.uib.no:11250/3024559 2023-05-15T16:21:57+02:00 Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes Ekblom Johansson, Fanny Bakke, Jostein Støren, Eivind Wilhelm Nagel Gillespie, Mette Kusk Laumann, Tron 2022-06-13 application/pdf https://hdl.handle.net/11250/3024559 https://doi.org/10.3389/feart.2022.886361 eng eng Frontiers urn:issn:2296-6463 https://hdl.handle.net/11250/3024559 https://doi.org/10.3389/feart.2022.886361 cristin:2047425 Frontiers in Earth Science. 2022, 10, 886361. Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright 2022 the authors 886361 Frontiers in Earth Science 10 Journal article Peer reviewed 2022 ftunivbergen https://doi.org/10.3389/feart.2022.886361 2023-03-14T17:39:54Z Folgefonna consists of three ice caps which are rapidly retreating in response to warmer temperatures. The melting of Folgefonna has implications for meltwater drainage and hydropower production, as well as the potential for geohazards and impacts to tourism, the communities and infrastructures surrounding the glacier. To support future adaptation strategies, we need to know the subglacial topography of the ice caps to identify water divides and possible areas for geohazards. Therefore, we mapped the subglacial topography at Sørfonna, the largest of the Folgefonna ice caps, using an ice-penetrating radar (2.5 MHz antennas; 1,000 × 500 m grid). The results show a highly irregular subglacial landscape, with deep valleys and high mountain peaks. The maximum ice thickness is 570 m and the mean ice thickness is 190 m. We examined the retreat pattern of Sørfonna using the subglacial topography map in combination with a simple ice flow model and simulated the ice retreat 150 years into the future. We used two climate scenarios (one with a 1.5°C warming and a 3% increase in precipitation, and a second with a 3.5°C warming together with 15% increase in precipitation) and focused on how the glacial retreat will cause hydrological changes in the catchments surrounding the glacier. The main drainage pattern shifts during glacial retreat, with a larger proportion of southward drainage compared to the present day. The ice flow modelling also reveals that the southern part of Sørfonna is more durable during climate change whereas the thinner part of the ice cap, in the north, melts faster. We suggest that increased winter precipitation in a future warmer climate makes the southern part of Sørfonna more resilient than many other glaciers in southern Norway. The subglacial topography map and the retreat pattern also reveal areas that may accumulate water and could potentially generate a future glacial outburst flood. Sediments from distal glacier-fed lakes around Sørfonna have been used to constrain the thresholds identified on ... Article in Journal/Newspaper glacier Ice cap University of Bergen: Bergen Open Research Archive (BORA-UiB) Norway Sørfonna ENVELOPE(23.061,23.061,79.576,79.576) Frontiers in Earth Science 10 |
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Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
Folgefonna consists of three ice caps which are rapidly retreating in response to warmer temperatures. The melting of Folgefonna has implications for meltwater drainage and hydropower production, as well as the potential for geohazards and impacts to tourism, the communities and infrastructures surrounding the glacier. To support future adaptation strategies, we need to know the subglacial topography of the ice caps to identify water divides and possible areas for geohazards. Therefore, we mapped the subglacial topography at Sørfonna, the largest of the Folgefonna ice caps, using an ice-penetrating radar (2.5 MHz antennas; 1,000 × 500 m grid). The results show a highly irregular subglacial landscape, with deep valleys and high mountain peaks. The maximum ice thickness is 570 m and the mean ice thickness is 190 m. We examined the retreat pattern of Sørfonna using the subglacial topography map in combination with a simple ice flow model and simulated the ice retreat 150 years into the future. We used two climate scenarios (one with a 1.5°C warming and a 3% increase in precipitation, and a second with a 3.5°C warming together with 15% increase in precipitation) and focused on how the glacial retreat will cause hydrological changes in the catchments surrounding the glacier. The main drainage pattern shifts during glacial retreat, with a larger proportion of southward drainage compared to the present day. The ice flow modelling also reveals that the southern part of Sørfonna is more durable during climate change whereas the thinner part of the ice cap, in the north, melts faster. We suggest that increased winter precipitation in a future warmer climate makes the southern part of Sørfonna more resilient than many other glaciers in southern Norway. The subglacial topography map and the retreat pattern also reveal areas that may accumulate water and could potentially generate a future glacial outburst flood. Sediments from distal glacier-fed lakes around Sørfonna have been used to constrain the thresholds identified on ... |
format |
Article in Journal/Newspaper |
author |
Ekblom Johansson, Fanny Bakke, Jostein Støren, Eivind Wilhelm Nagel Gillespie, Mette Kusk Laumann, Tron |
spellingShingle |
Ekblom Johansson, Fanny Bakke, Jostein Støren, Eivind Wilhelm Nagel Gillespie, Mette Kusk Laumann, Tron Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes |
author_facet |
Ekblom Johansson, Fanny Bakke, Jostein Støren, Eivind Wilhelm Nagel Gillespie, Mette Kusk Laumann, Tron |
author_sort |
Ekblom Johansson, Fanny |
title |
Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes |
title_short |
Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes |
title_full |
Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes |
title_fullStr |
Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes |
title_full_unstemmed |
Mapping of the Subglacial Topography of Folgefonna Ice Cap in Western Norway—Consequences for Ice Retreat Patterns and Hydrological Changes |
title_sort |
mapping of the subglacial topography of folgefonna ice cap in western norway—consequences for ice retreat patterns and hydrological changes |
publisher |
Frontiers |
publishDate |
2022 |
url |
https://hdl.handle.net/11250/3024559 https://doi.org/10.3389/feart.2022.886361 |
long_lat |
ENVELOPE(23.061,23.061,79.576,79.576) |
geographic |
Norway Sørfonna |
geographic_facet |
Norway Sørfonna |
genre |
glacier Ice cap |
genre_facet |
glacier Ice cap |
op_source |
886361 Frontiers in Earth Science 10 |
op_relation |
urn:issn:2296-6463 https://hdl.handle.net/11250/3024559 https://doi.org/10.3389/feart.2022.886361 cristin:2047425 Frontiers in Earth Science. 2022, 10, 886361. |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no Copyright 2022 the authors |
op_doi |
https://doi.org/10.3389/feart.2022.886361 |
container_title |
Frontiers in Earth Science |
container_volume |
10 |
_version_ |
1766009927540670464 |