Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions
In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of grou...
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Online Access: | http://hdl.handle.net/11383/2005523 https://doi.org/10.1016/j.geomorph.2014.03.051 |
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ftuninsubriairis:oai:irinsubria.uninsubria.it:11383/2005523 2024-04-14T08:00:12+00:00 Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions GUGLIELMIN, MAURO Worland, M. R. Baio, F. Convey, P. Guglielmin, Mauro Worland, M. R. Baio, F. Convey, P. 2014 STAMPA http://hdl.handle.net/11383/2005523 https://doi.org/10.1016/j.geomorph.2014.03.051 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000342714900005 volume:225 firstpage:47 lastpage:56 numberofpages:10 journal:GEOMORPHOLOGY http://hdl.handle.net/11383/2005523 doi:10.1016/j.geomorph.2014.03.051 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84899777900 Permafrost Antarctica Active layer Ground surface temperature Rock weathering info:eu-repo/semantics/article 2014 ftuninsubriairis https://doi.org/10.1016/j.geomorph.2014.03.051 2024-03-21T19:00:18Z In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of ground surface temperature (GST) is characterised through the monitoring of snow depth on 5 stakes positioned around the borehole and with thermistors placed at three different rock surfaces (A, B and C). The borehole temperature is measured by 18 thermistors placed at different depths between 0.3 and 30 m. Snow persistence is very variable both spatially and temporally with snow free days per year ranging from 13 and more than 300, and maximum snow depths varying between 0.03 and 1.42 m. This variability is the main cause of high variability in GST, that ranged between − 3.7 and − 1.5 °C. The net effect of the snow cover is a cooling of the surface. Mean annual GST, mean summer GST, and the degree days of thawing and the n-factor of thawing were always much lower at sensor A where snow persistence and depth were greater than in the other sensor locations. At sensor A the potential freeze–thaw events were negligible (0–3) and the thermal stress was at least 40% less than in the other sensor locations. The zero curtain effect at the rock surface occurred only at surface A, favouring chemical weathering over mechanical action. The active layer thickness (ALT) ranged between 0.76 and 1.40 m. ALT was directly proportional to the mean air temperature in summer, and inversely proportional to the maximum snow depth in autumn. ALT temporal variability was greater than reported at other sites at similar latitude in the Northern Hemisphere, or with the similar mean annual air temperature in Maritime Antarctica, because vegetation and a soil organic horizon are absent at the study site. Zero annual amplitude in temperature was observed at about 16 m depth, where the mean annual temperature is − 3 °C. Permafrost thickness was ... Article in Journal/Newspaper Active layer thickness Adelaide Island Antarc* Antarctic Antarctica British Antarctic Survey permafrost IRInSubria - Institutional Repository Insubria (Università degli Studi dell’Insubria) Antarctic Rothera ENVELOPE(-68.130,-68.130,-67.568,-67.568) Adelaide Island ENVELOPE(-68.914,-68.914,-67.762,-67.762) Rothera Point ENVELOPE(-68.133,-68.133,-67.567,-67.567) Geomorphology 225 47 56 |
institution |
Open Polar |
collection |
IRInSubria - Institutional Repository Insubria (Università degli Studi dell’Insubria) |
op_collection_id |
ftuninsubriairis |
language |
English |
topic |
Permafrost Antarctica Active layer Ground surface temperature Rock weathering |
spellingShingle |
Permafrost Antarctica Active layer Ground surface temperature Rock weathering GUGLIELMIN, MAURO Worland, M. R. Baio, F. Convey, P. Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions |
topic_facet |
Permafrost Antarctica Active layer Ground surface temperature Rock weathering |
description |
In February 2009 a new permafrost borehole was installed close to the British Antarctic Survey Station at Rothera Point, Adelaide Island (67.57195°S 68.12068°W). The borehole is situated at 31 m asl on a granodiorite knob with scattered lichen cover. The spatial variability of snow cover and of ground surface temperature (GST) is characterised through the monitoring of snow depth on 5 stakes positioned around the borehole and with thermistors placed at three different rock surfaces (A, B and C). The borehole temperature is measured by 18 thermistors placed at different depths between 0.3 and 30 m. Snow persistence is very variable both spatially and temporally with snow free days per year ranging from 13 and more than 300, and maximum snow depths varying between 0.03 and 1.42 m. This variability is the main cause of high variability in GST, that ranged between − 3.7 and − 1.5 °C. The net effect of the snow cover is a cooling of the surface. Mean annual GST, mean summer GST, and the degree days of thawing and the n-factor of thawing were always much lower at sensor A where snow persistence and depth were greater than in the other sensor locations. At sensor A the potential freeze–thaw events were negligible (0–3) and the thermal stress was at least 40% less than in the other sensor locations. The zero curtain effect at the rock surface occurred only at surface A, favouring chemical weathering over mechanical action. The active layer thickness (ALT) ranged between 0.76 and 1.40 m. ALT was directly proportional to the mean air temperature in summer, and inversely proportional to the maximum snow depth in autumn. ALT temporal variability was greater than reported at other sites at similar latitude in the Northern Hemisphere, or with the similar mean annual air temperature in Maritime Antarctica, because vegetation and a soil organic horizon are absent at the study site. Zero annual amplitude in temperature was observed at about 16 m depth, where the mean annual temperature is − 3 °C. Permafrost thickness was ... |
author2 |
Guglielmin, Mauro Worland, M. R. Baio, F. Convey, P. |
format |
Article in Journal/Newspaper |
author |
GUGLIELMIN, MAURO Worland, M. R. Baio, F. Convey, P. |
author_facet |
GUGLIELMIN, MAURO Worland, M. R. Baio, F. Convey, P. |
author_sort |
GUGLIELMIN, MAURO |
title |
Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions |
title_short |
Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions |
title_full |
Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions |
title_fullStr |
Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions |
title_full_unstemmed |
Permafrost and snow monitoring at Rothera Point (Adelaide Island, Maritime Antarctica): Implications for rock weathering in cryotic conditions |
title_sort |
permafrost and snow monitoring at rothera point (adelaide island, maritime antarctica): implications for rock weathering in cryotic conditions |
publishDate |
2014 |
url |
http://hdl.handle.net/11383/2005523 https://doi.org/10.1016/j.geomorph.2014.03.051 |
long_lat |
ENVELOPE(-68.130,-68.130,-67.568,-67.568) ENVELOPE(-68.914,-68.914,-67.762,-67.762) ENVELOPE(-68.133,-68.133,-67.567,-67.567) |
geographic |
Antarctic Rothera Adelaide Island Rothera Point |
geographic_facet |
Antarctic Rothera Adelaide Island Rothera Point |
genre |
Active layer thickness Adelaide Island Antarc* Antarctic Antarctica British Antarctic Survey permafrost |
genre_facet |
Active layer thickness Adelaide Island Antarc* Antarctic Antarctica British Antarctic Survey permafrost |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000342714900005 volume:225 firstpage:47 lastpage:56 numberofpages:10 journal:GEOMORPHOLOGY http://hdl.handle.net/11383/2005523 doi:10.1016/j.geomorph.2014.03.051 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84899777900 |
op_doi |
https://doi.org/10.1016/j.geomorph.2014.03.051 |
container_title |
Geomorphology |
container_volume |
225 |
container_start_page |
47 |
op_container_end_page |
56 |
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1796316668148842496 |