Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif).
Since the early 2000s, a remarkable amount of rockfalls has been observed in permafrost areas of the mid-latitude mountain ranges concurrently to hot summers. This study explores the seasonal thaw (ST) in permafrost rock walls of the Aiguille du Midi site (3842 m a.s.l., Mont Blanc massif). We first...
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fttriple:oai:gotriple.eu:10670/1.zqsua0 2023-05-15T13:03:18+02:00 Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif). Magnin, Florence Westermann, Sebastien Pogliotti, Paolo Ravanel, Ludovic Deline, Philip Malet, Emmanuel Environnements, Dynamiques et Territoires de la Montagne (EDYTEM) Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS) Department of Geosciences Oslo Faculty of Mathematics and Natural Sciences Oslo University of Oslo (UiO)-University of Oslo (UiO) ARPA Valle d'Aosta (Aosta Valley Regional Environmental Protection Agency) Aosta Valley Regional Environmental Protection Agency (ARPA) 2017-01-01 https://hal-sde.archives-ouvertes.fr/hal-01778287 en eng HAL CCSD Elsevier hal-01778287 10670/1.zqsua0 https://hal-sde.archives-ouvertes.fr/hal-01778287 undefined Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0341-8162 CATENA CATENA, Elsevier, 2017, 149, p648-p662 Active layer Rock wall permafrost Snow Energy balance modelling Bedrock temperature monitoring geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2017 fttriple 2023-01-22T17:43:49Z Since the early 2000s, a remarkable amount of rockfalls has been observed in permafrost areas of the mid-latitude mountain ranges concurrently to hot summers. This study explores the seasonal thaw (ST) in permafrost rock walls of the Aiguille du Midi site (3842 m a.s.l., Mont Blanc massif). We first analyse six years of temperature records in three 10 m-deep boreholes against air temperature (AT) and a four-year time series of pictures showing the snow conditions on two rock faces. Then, we test the sensitivity of the active layer against eight snow fall scenarios using the 1-D surface energy balance and heat conduction model CryoGrid 3 forced by in-situ measurements from a vertical face. Snow falls occur all the year round at this elevation and play an important role for the active layer thickness (ALT), but the snow cover and its control are highly heterogeneous. A long-lasting of a snow cover during spring/early summer delays the ST and reduces the ALT. The thicker and the more spatially-continuous is the snow cover, the stronger are the delay and ALT reduction. Convective clouds could also reinforce this pattern. The summer AT and heat waves are the dominant controlling factors of the ALT. But summer snow falls can sometimes persist for several days on the rock surface and reduce the effect of the heat waves. Active layer can thicken during the early fall, except if the snow starts to accumulate on the rock surface and favours the refreezing. The timing of the snow fall is the most critical parameter to determine the snow effect on the ALT. This study suggests that the characteristics of the bedrock and snow accumulation (steepness, surface roughness, and sun-exposure) must be taken into account to better understand the formation and changes of the active layer and its possible implications for rockfall triggering. Article in Journal/Newspaper Active layer thickness permafrost Unknown Mont Blanc ENVELOPE(69.468,69.468,-49.461,-49.461) |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
Active layer Rock wall permafrost Snow Energy balance modelling Bedrock temperature monitoring geo envir |
spellingShingle |
Active layer Rock wall permafrost Snow Energy balance modelling Bedrock temperature monitoring geo envir Magnin, Florence Westermann, Sebastien Pogliotti, Paolo Ravanel, Ludovic Deline, Philip Malet, Emmanuel Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif). |
topic_facet |
Active layer Rock wall permafrost Snow Energy balance modelling Bedrock temperature monitoring geo envir |
description |
Since the early 2000s, a remarkable amount of rockfalls has been observed in permafrost areas of the mid-latitude mountain ranges concurrently to hot summers. This study explores the seasonal thaw (ST) in permafrost rock walls of the Aiguille du Midi site (3842 m a.s.l., Mont Blanc massif). We first analyse six years of temperature records in three 10 m-deep boreholes against air temperature (AT) and a four-year time series of pictures showing the snow conditions on two rock faces. Then, we test the sensitivity of the active layer against eight snow fall scenarios using the 1-D surface energy balance and heat conduction model CryoGrid 3 forced by in-situ measurements from a vertical face. Snow falls occur all the year round at this elevation and play an important role for the active layer thickness (ALT), but the snow cover and its control are highly heterogeneous. A long-lasting of a snow cover during spring/early summer delays the ST and reduces the ALT. The thicker and the more spatially-continuous is the snow cover, the stronger are the delay and ALT reduction. Convective clouds could also reinforce this pattern. The summer AT and heat waves are the dominant controlling factors of the ALT. But summer snow falls can sometimes persist for several days on the rock surface and reduce the effect of the heat waves. Active layer can thicken during the early fall, except if the snow starts to accumulate on the rock surface and favours the refreezing. The timing of the snow fall is the most critical parameter to determine the snow effect on the ALT. This study suggests that the characteristics of the bedrock and snow accumulation (steepness, surface roughness, and sun-exposure) must be taken into account to better understand the formation and changes of the active layer and its possible implications for rockfall triggering. |
author2 |
Environnements, Dynamiques et Territoires de la Montagne (EDYTEM) Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS) Department of Geosciences Oslo Faculty of Mathematics and Natural Sciences Oslo University of Oslo (UiO)-University of Oslo (UiO) ARPA Valle d'Aosta (Aosta Valley Regional Environmental Protection Agency) Aosta Valley Regional Environmental Protection Agency (ARPA) |
format |
Article in Journal/Newspaper |
author |
Magnin, Florence Westermann, Sebastien Pogliotti, Paolo Ravanel, Ludovic Deline, Philip Malet, Emmanuel |
author_facet |
Magnin, Florence Westermann, Sebastien Pogliotti, Paolo Ravanel, Ludovic Deline, Philip Malet, Emmanuel |
author_sort |
Magnin, Florence |
title |
Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif). |
title_short |
Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif). |
title_full |
Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif). |
title_fullStr |
Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif). |
title_full_unstemmed |
Snow control on active layer thickness in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l., Mont Blanc massif). |
title_sort |
snow control on active layer thickness in steep alpine rock walls (aiguille du midi, 3842 m a.s.l., mont blanc massif). |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://hal-sde.archives-ouvertes.fr/hal-01778287 |
long_lat |
ENVELOPE(69.468,69.468,-49.461,-49.461) |
geographic |
Mont Blanc |
geographic_facet |
Mont Blanc |
genre |
Active layer thickness permafrost |
genre_facet |
Active layer thickness permafrost |
op_source |
Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0341-8162 CATENA CATENA, Elsevier, 2017, 149, p648-p662 |
op_relation |
hal-01778287 10670/1.zqsua0 https://hal-sde.archives-ouvertes.fr/hal-01778287 |
op_rights |
undefined |
_version_ |
1766333316162650112 |