Post-Little Ice Age rock wall permafrost evolution in Norway
<p>The ground thermal regime and permafrost development have an important influence on geomorphological processes in periglacial regions and ultimately landscape development. About 10 % of unstable rock slopes in Norway are potentially underlain by widespread permafrost. Permafrost thaw and de...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-07-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/2725/2023/tc-17-2725-2023.pdf |
| _version_ | 1797781765963644928 |
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| author | J. Czekirda B. Etzelmüller S. Westermann K. Isaksen F. Magnin |
| author_facet | J. Czekirda B. Etzelmüller S. Westermann K. Isaksen F. Magnin |
| author_sort | J. Czekirda |
| collection | DOAJ |
| description | <p>The ground thermal regime and permafrost development have an important influence on geomorphological processes in periglacial regions and ultimately
landscape development. About 10 % of unstable rock slopes in Norway are potentially underlain by widespread permafrost. Permafrost thaw and
degradation may play a role in slope destabilisation, and more knowledge about rock wall permafrost in Norway is needed to investigate possible links
between the ground thermal regime, geomorphological activity and natural hazards. We assess spatio-temporal permafrost variations in selected rock
walls in Norway over the last 120 years. Ground temperature is modelled using the two-dimensional ground heat flux model CryoGrid 2D along nine
profiles crossing instrumented rock walls in Norway. The simulation results show the distribution of permafrost is sporadic to continuous along the
modelled profiles. Results suggest that ground temperature at 20 <span class="inline-formula">m</span> depth in steep rock faces increased by 0.2 <span class="inline-formula"><sup>∘</sup></span>C per decade on average
since the 1980s, and rates of change increase with elevation within a single rock wall section. Heat flow direction is primarily vertical within
mountains in Norway. Nevertheless, narrow ridges may still be sensitive to even small differences in ground surface temperature and may have
horizontal heat fluxes. This study further demonstrates how rock wall temperature increase rates and rock wall permafrost distribution are
influenced by factors such as surface air temperature uncertainties; surface offsets arising from the incoming shortwave solar radiation; snow
conditions on, above and below rock walls; and rock wall geometry and size together with adjacent blockfield-covered plateaus or glaciers.</p> |
| first_indexed | 2024-03-13T00:01:44Z |
| format | Article |
| id | doaj.art-3988616b768f43f89e7f947b93b0751d |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-03-13T00:01:44Z |
| publishDate | 2023-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-3988616b768f43f89e7f947b93b0751d2023-07-13T06:11:08ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242023-07-01172725275410.5194/tc-17-2725-2023Post-Little Ice Age rock wall permafrost evolution in NorwayJ. Czekirda0B. Etzelmüller1S. Westermann2K. Isaksen3F. Magnin4Department of Geosciences, University of Oslo, 0316 Oslo, NorwayDepartment of Geosciences, University of Oslo, 0316 Oslo, NorwayDepartment of Geosciences, University of Oslo, 0316 Oslo, NorwayDepartment of Research and Development, Norwegian Meteorological Institute, 0313 Oslo, NorwayEDYTEM, Université Savoie Mont Blanc, CNRS, 73000 Chambery, France<p>The ground thermal regime and permafrost development have an important influence on geomorphological processes in periglacial regions and ultimately landscape development. About 10 % of unstable rock slopes in Norway are potentially underlain by widespread permafrost. Permafrost thaw and degradation may play a role in slope destabilisation, and more knowledge about rock wall permafrost in Norway is needed to investigate possible links between the ground thermal regime, geomorphological activity and natural hazards. We assess spatio-temporal permafrost variations in selected rock walls in Norway over the last 120 years. Ground temperature is modelled using the two-dimensional ground heat flux model CryoGrid 2D along nine profiles crossing instrumented rock walls in Norway. The simulation results show the distribution of permafrost is sporadic to continuous along the modelled profiles. Results suggest that ground temperature at 20 <span class="inline-formula">m</span> depth in steep rock faces increased by 0.2 <span class="inline-formula"><sup>∘</sup></span>C per decade on average since the 1980s, and rates of change increase with elevation within a single rock wall section. Heat flow direction is primarily vertical within mountains in Norway. Nevertheless, narrow ridges may still be sensitive to even small differences in ground surface temperature and may have horizontal heat fluxes. This study further demonstrates how rock wall temperature increase rates and rock wall permafrost distribution are influenced by factors such as surface air temperature uncertainties; surface offsets arising from the incoming shortwave solar radiation; snow conditions on, above and below rock walls; and rock wall geometry and size together with adjacent blockfield-covered plateaus or glaciers.</p>https://tc.copernicus.org/articles/17/2725/2023/tc-17-2725-2023.pdf |
| spellingShingle | J. Czekirda B. Etzelmüller S. Westermann K. Isaksen F. Magnin Post-Little Ice Age rock wall permafrost evolution in Norway The Cryosphere |
| title | Post-Little Ice Age rock wall permafrost evolution in Norway |
| title_full | Post-Little Ice Age rock wall permafrost evolution in Norway |
| title_fullStr | Post-Little Ice Age rock wall permafrost evolution in Norway |
| title_full_unstemmed | Post-Little Ice Age rock wall permafrost evolution in Norway |
| title_short | Post-Little Ice Age rock wall permafrost evolution in Norway |
| title_sort | post little ice age rock wall permafrost evolution in norway |
| url | https://tc.copernicus.org/articles/17/2725/2023/tc-17-2725-2023.pdf |
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