Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processes
<p>Permafrost in steep rock slopes has been increasingly studied since the early 2000s in conjunction with a growing number of rock slope failures, which likely resulted from permafrost degradation. In Norway, rock slope destabilization is a widespread phenomenon and a major source of risk for...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-10-01
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| Series: | Earth Surface Dynamics |
| Online Access: | https://www.earth-surf-dynam.net/7/1019/2019/esurf-7-1019-2019.pdf |
| _version_ | 1818420828145975296 |
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| author | F. Magnin B. Etzelmüller S. Westermann K. Isaksen P. Hilger P. Hilger R. L. Hermanns R. L. Hermanns |
| author_facet | F. Magnin B. Etzelmüller S. Westermann K. Isaksen P. Hilger P. Hilger R. L. Hermanns R. L. Hermanns |
| author_sort | F. Magnin |
| collection | DOAJ |
| description | <p>Permafrost in steep rock slopes has been increasingly studied
since the early 2000s in conjunction with a growing number of rock slope
failures, which likely resulted from permafrost degradation. In Norway, rock
slope destabilization is a widespread phenomenon and a major source of risk
for the population and infrastructure. However, a lack of precise
knowledge of the permafrost distribution in steep slopes hinders the
assessment of its role in these destabilizations. This study proposes the
first nationwide permafrost probability map for the steep slopes of Norway
(CryoWall map). It is based on a multiple linear regression model fitted
with multi-annual rock surface temperature (RST) measurements, collected at
25 rock slope sites, spread across a latitudinal transect (59–69<span class="inline-formula"><sup>∘</sup></span> N) over mainland Norway. The CryoWall map suggests that discontinuous
permafrost widely occurs above 1300–1400 and 1600–1700 m a.s.l. in the north
and south rock faces of southern Norway (59<span class="inline-formula"><sup>∘</sup></span> N), respectively.
This lower altitudinal limit decreases in northern Norway (70<span class="inline-formula"><sup>∘</sup></span> N)
by about <span class="inline-formula">500±50</span> m, with a more pronounced decrease for south faces, as
a result of the insolation patterns largely driven by midnight sun in summer
and polar night in winter. Similarly, the mean annual RST differences
between north and south faces of similar elevation range around
1.5 <span class="inline-formula"><sup>∘</sup></span>C in northern Norway and 3.5 <span class="inline-formula"><sup>∘</sup></span>C in southern Norway.
The CryoWall map is evaluated against direct ice observations in steep
slopes and discussed in the context of former permafrost studies in various
types of terrain in Norway. We show that permafrost can occur at much lower
elevations in steep rock slopes than in other terrains, especially in north
faces. We demonstrate that the CryoWall map is a valuable basis for further
investigations related to permafrost in steep slopes in terms of both practical
concerns and fundamental science.</p> |
| first_indexed | 2024-12-14T13:00:40Z |
| format | Article |
| id | doaj.art-fa02fbdb7a9c4eda89d1cd4952281635 |
| institution | Directory Open Access Journal |
| issn | 2196-6311 2196-632X |
| language | English |
| last_indexed | 2024-12-14T13:00:40Z |
| publishDate | 2019-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Earth Surface Dynamics |
| spelling | doaj.art-fa02fbdb7a9c4eda89d1cd49522816352022-12-21T23:00:27ZengCopernicus PublicationsEarth Surface Dynamics2196-63112196-632X2019-10-0171019104010.5194/esurf-7-1019-2019Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processesF. Magnin0B. Etzelmüller1S. Westermann2K. Isaksen3P. Hilger4P. Hilger5R. L. Hermanns6R. L. Hermanns7Department of Geosciences, University of Oslo, Oslo, 0316, NorwayDepartment of Geosciences, University of Oslo, Oslo, 0316, NorwayDepartment of Geosciences, University of Oslo, Oslo, 0316, NorwayThe Norwegian Meteorological Institute, Oslo, 0313, NorwayDepartment of Geosciences, University of Oslo, Oslo, 0316, NorwayGeological Survey of Norway, Trondheim, 7040, NorwayGeological Survey of Norway, Trondheim, 7040, NorwayInstitute for Geoscience and Petroleum, Norwegian University of Science and Technology, Trondheim, 7040, Norway<p>Permafrost in steep rock slopes has been increasingly studied since the early 2000s in conjunction with a growing number of rock slope failures, which likely resulted from permafrost degradation. In Norway, rock slope destabilization is a widespread phenomenon and a major source of risk for the population and infrastructure. However, a lack of precise knowledge of the permafrost distribution in steep slopes hinders the assessment of its role in these destabilizations. This study proposes the first nationwide permafrost probability map for the steep slopes of Norway (CryoWall map). It is based on a multiple linear regression model fitted with multi-annual rock surface temperature (RST) measurements, collected at 25 rock slope sites, spread across a latitudinal transect (59–69<span class="inline-formula"><sup>∘</sup></span> N) over mainland Norway. The CryoWall map suggests that discontinuous permafrost widely occurs above 1300–1400 and 1600–1700 m a.s.l. in the north and south rock faces of southern Norway (59<span class="inline-formula"><sup>∘</sup></span> N), respectively. This lower altitudinal limit decreases in northern Norway (70<span class="inline-formula"><sup>∘</sup></span> N) by about <span class="inline-formula">500±50</span> m, with a more pronounced decrease for south faces, as a result of the insolation patterns largely driven by midnight sun in summer and polar night in winter. Similarly, the mean annual RST differences between north and south faces of similar elevation range around 1.5 <span class="inline-formula"><sup>∘</sup></span>C in northern Norway and 3.5 <span class="inline-formula"><sup>∘</sup></span>C in southern Norway. The CryoWall map is evaluated against direct ice observations in steep slopes and discussed in the context of former permafrost studies in various types of terrain in Norway. We show that permafrost can occur at much lower elevations in steep rock slopes than in other terrains, especially in north faces. We demonstrate that the CryoWall map is a valuable basis for further investigations related to permafrost in steep slopes in terms of both practical concerns and fundamental science.</p>https://www.earth-surf-dynam.net/7/1019/2019/esurf-7-1019-2019.pdf |
| spellingShingle | F. Magnin B. Etzelmüller S. Westermann K. Isaksen P. Hilger P. Hilger R. L. Hermanns R. L. Hermanns Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processes Earth Surface Dynamics |
| title | Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processes |
| title_full | Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processes |
| title_fullStr | Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processes |
| title_full_unstemmed | Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processes |
| title_short | Permafrost distribution in steep rock slopes in Norway: measurements, statistical modelling and implications for geomorphological processes |
| title_sort | permafrost distribution in steep rock slopes in norway measurements statistical modelling and implications for geomorphological processes |
| url | https://www.earth-surf-dynam.net/7/1019/2019/esurf-7-1019-2019.pdf |
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