Utilisation d'un géoradar pour l'étude du couvert nival à la limite des arbres, Churchill, Manitoba

Use of Ground Penetrating Radar for Studying Snow Cover at Treeline, Churchill, Manitoba

¹ Laboratoire de Télédétection de Modélisation des Environnements Froids, Dpt de Géographie, Université Laval, Sainte-Foy (QC), G1K 7P4, Canada
² Geophysical Institute, University of Alaska Fairbanks, 900 Yukon Drive, P.O. Box 755780, Fairbanks (AK) 99775-5780, USA
³ Laboratoire des Milieux Anthropisés, CNRS FRE 2170, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, 59655 Cedex, France

Abstract

We present some results of an investigation on the use of a ground penetrating radar (GPR) to measure snow depth and stratigraphic variations, at local scale, of a subarctic snow cover located in the forest-tundra transition zone (trecline), near Churchill, Manitoba, Canada. CMP and reflection profiles were performed on a highly metamorphised snowpack, in March 1998, using a GPR operating at 900 MHz. A comparison with stratigraphic information obtained from a traditional snow profile at the same site allows to identify the various reflectors with a precision better than 2 cm. These correspond to 1) the contact between the snow cover and the underlying ground and 2) several boundaries between depthhoar and faceted crystal layers occurring inside the snowpack.