Some observations on snowpack features in Northern Victoria Land, Antarctica

Abstract

The first results of snowpack observations carried out in Antarctica during the Italian scientific expedition in 1994/95 winter are presented here. In a mountainous area of about 50,000 km² in the Northern Victoria Land, where the Terra Nova Station is located, several conventional snow profiles were performed at variable depths, from some centimeters to a maximum of one meter according to situation. Observations have been carried out utilizing the traditional field instruments. In particular, for every snow profile the following characteristics were analysed: grain shape and grain size, hardness index, density, liquid water content and snow temperature. During the helicopter flights, observations on avalanche activity were also made. Analysis of snow profiles has high lighted some characteristics that distinguish antarctic from alpine snowpack. In general, a low structural diversification was found with an alternance of layers of small rounded particles and layers of faceted crystals, Hardness index profiles present on average patterms of «quasi-hydrostatic» type that confer a relative stability on the snowpacks. Snow characteristics integrated with climatological analysis of the period made possible to formulate some hypotheses on the low avalanche activity observed in the region.