Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years
Palsas and peat plateaus are permafrost landforms occurring in subarctic mires which constitute sensitive ecosystems with strong significance for vegetation, wildlife, hydrology and carbon cycle. Firstly, we have systematically mapped the occurrence of palsas and peat plateaus in the northernmost co...
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ftdoajarticles:oai:doaj.org/article:1565efd8e29f4f5f8daa34c0eed94fa8 2023-05-15T16:13:35+02:00 Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years A. F. Borge S. Westermann I. Solheim B. Etzelmüller 2017-01-01T00:00:00Z https://doi.org/10.5194/tc-11-1-2017 https://doaj.org/article/1565efd8e29f4f5f8daa34c0eed94fa8 EN eng Copernicus Publications http://www.the-cryosphere.net/11/1/2017/tc-11-1-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-1-2017 https://doaj.org/article/1565efd8e29f4f5f8daa34c0eed94fa8 The Cryosphere, Vol 11, Iss 1, Pp 1-16 (2017) Environmental sciences GE1-350 Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/tc-11-1-2017 2022-12-30T22:11:32Z Palsas and peat plateaus are permafrost landforms occurring in subarctic mires which constitute sensitive ecosystems with strong significance for vegetation, wildlife, hydrology and carbon cycle. Firstly, we have systematically mapped the occurrence of palsas and peat plateaus in the northernmost county of Norway (Finnmark, ∼ 50 000 km 2 ) by manual interpretation of aerial images from 2005 to 2014 at a spatial resolution of 250 m. At this resolution, mires and wetlands with palsas or peat plateaus occur in about 850 km 2 of Finnmark, with the actual palsas and peat plateaus underlain by permafrost covering a surface area of approximately 110 km 2 . Secondly, we have quantified the lateral changes of the extent of palsas and peat plateaus for four study areas located along a NW–SE transect through Finnmark by utilizing repeat aerial imagery from the 1950s to the 2010s. The results of the lateral changes reveal a total decrease of 33–71 % in the areal extent of palsas and peat plateaus during the study period, with the largest lateral change rates observed in the last decade. However, the results indicate that degradation of palsas and peat plateaus in northern Norway has been a consistent process during the second half of the 20th century and possibly even earlier. Significant rates of areal change are observed in all investigated time periods since the 1950s, and thermokarst landforms observed on aerial images from the 1950s suggest that lateral degradation was already an ongoing process at this time. The results of this study show that lateral erosion of palsas and peat plateaus is an important pathway for permafrost degradation in the sporadic permafrost zone in northern Scandinavia. While the environmental factors governing the rate of erosion are not yet fully understood, we note a moderate increase in air temperature, precipitation and snow depth during the last few decades in the region. Article in Journal/Newspaper Finnmark Northern Norway palsas Peat permafrost Subarctic The Cryosphere Thermokarst Finnmark Directory of Open Access Journals: DOAJ Articles Norway The Cryosphere 11 1 1 16 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 A. F. Borge S. Westermann I. Solheim B. Etzelmüller Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Palsas and peat plateaus are permafrost landforms occurring in subarctic mires which constitute sensitive ecosystems with strong significance for vegetation, wildlife, hydrology and carbon cycle. Firstly, we have systematically mapped the occurrence of palsas and peat plateaus in the northernmost county of Norway (Finnmark, ∼ 50 000 km 2 ) by manual interpretation of aerial images from 2005 to 2014 at a spatial resolution of 250 m. At this resolution, mires and wetlands with palsas or peat plateaus occur in about 850 km 2 of Finnmark, with the actual palsas and peat plateaus underlain by permafrost covering a surface area of approximately 110 km 2 . Secondly, we have quantified the lateral changes of the extent of palsas and peat plateaus for four study areas located along a NW–SE transect through Finnmark by utilizing repeat aerial imagery from the 1950s to the 2010s. The results of the lateral changes reveal a total decrease of 33–71 % in the areal extent of palsas and peat plateaus during the study period, with the largest lateral change rates observed in the last decade. However, the results indicate that degradation of palsas and peat plateaus in northern Norway has been a consistent process during the second half of the 20th century and possibly even earlier. Significant rates of areal change are observed in all investigated time periods since the 1950s, and thermokarst landforms observed on aerial images from the 1950s suggest that lateral degradation was already an ongoing process at this time. The results of this study show that lateral erosion of palsas and peat plateaus is an important pathway for permafrost degradation in the sporadic permafrost zone in northern Scandinavia. While the environmental factors governing the rate of erosion are not yet fully understood, we note a moderate increase in air temperature, precipitation and snow depth during the last few decades in the region. |
format |
Article in Journal/Newspaper |
author |
A. F. Borge S. Westermann I. Solheim B. Etzelmüller |
author_facet |
A. F. Borge S. Westermann I. Solheim B. Etzelmüller |
author_sort |
A. F. Borge |
title |
Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years |
title_short |
Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years |
title_full |
Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years |
title_fullStr |
Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years |
title_full_unstemmed |
Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years |
title_sort |
strong degradation of palsas and peat plateaus in northern norway during the last 60 years |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-1-2017 https://doaj.org/article/1565efd8e29f4f5f8daa34c0eed94fa8 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Finnmark Northern Norway palsas Peat permafrost Subarctic The Cryosphere Thermokarst Finnmark |
genre_facet |
Finnmark Northern Norway palsas Peat permafrost Subarctic The Cryosphere Thermokarst Finnmark |
op_source |
The Cryosphere, Vol 11, Iss 1, Pp 1-16 (2017) |
op_relation |
http://www.the-cryosphere.net/11/1/2017/tc-11-1-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-11-1-2017 https://doaj.org/article/1565efd8e29f4f5f8daa34c0eed94fa8 |
op_doi |
https://doi.org/10.5194/tc-11-1-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
1 |
container_start_page |
1 |
op_container_end_page |
16 |
_version_ |
1765999374015397888 |