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

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 (treeline), 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.