Mots-clés
Effondrement ; Finlande ; Finlande du Nord-Ouest ; GPR ; Géophysique ; Milieu humide ; Modèle ; Palse ; Pergélisol ; Réchauffement climatique ; Température du sol ; Thermodynamique ; Zone froideClimatic warming ; Cold area ; Collapse structures ; Finland ; Geophysics ; Ground penetrating radar ; Humid environment ; Model ; Northwest Finland ; Palsa ; Permafrost ; Soil temperature ; ThermodynamicsDesmoronamiento ; Finlandia ; Geofísica ; Medio húmedo ; Modelo ; Palsa ; Pergelisol ; Recalentamiento climático ; Temperatura del suelo ; Zona fríaNon-invasive geophysical investigation and thermodynamic analysis of a palsa in Lapland, Northwest Finland
Auteur(s) et Affiliation(s)
KOHOUT, T.
Dept. of Physics, Univ., Helsinki, Finlande
Inst. of Geology ASCR, Prague, Tcheque, Republique
BUĆKO, M.S.
Dept. of Physics, Univ., Helsinki, Finlande
LEPPÄRANTA, M.
Dept. of Physics, Univ., Helsinki, Finlande
MATERO, I.
Dept. of Physics, Univ., Helsinki, Finlande
Finnish Meteorological Inst., Helsinki, Finlande
Description :
Non-invasive geophysical prospecting and a thermodynamic model were used to examine the structure, depth and lateral extent of the frozen core of a palsa near Lake Peerajärvi. A simple thermodynamic model verified that the current climatic conditions in the study area allow sustainable palsa development. A ground penetrating radar (GPR) survey of the palsa under both winter and summer conditions revealed its internal structure and the size of its frozen core. GPR imaging in summer detected the upper peat/core boundary, and imaging in winter detected a deep reflector that probably represents the lower core boundary. This indicates that only a combined summer and winter GPR survey completely reveals the lateral and vertical extent of the frozen core of the palsa. The presence of the frozen core could also be traced as minima in surface temperature and ground conductivity measurements. These field methods and thermodynamic models can be utilised in studies of climate impact on Arctic wetlands.
Type de document :
Article de périodique
Source :
Permafrost and periglacial processes, issn : 1045-6740, 2014, vol. 25, n°. 1, p. 45-52, nombre de pages : 8, Références bibliographiques : 25 ref.
Date :
2014
Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley
Langue :
Anglais
Anglais
Droits :
Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI)
Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI)