Snow Profiles and Avalanche Activity in the Cairngorm Mountains, Scotland

Abstract

AbstractThe paper presents data on the snow cover in the Cairngorm Mountains, Scotland, and compares typical Scottish snow profiles with those measured in alpine, continental, and polar areas. The paper shows that in the Cairngorms snow temperatures are higher and as a result densities and ram penetration resistances are also higher. Typical densities are between 350 and 500 kg m−3and ram resistances are frequently above 50 or even 100 kg. Typical profiles show large masses of windslab above an equigranular basal layer of old snow, and ice layers are common throughout the profile. Avalanche activity is related to two types of profile both of which share low ram resistance in common. Dry-slab avalanches release when densities are of the order of 250 kg m−3or less and snow temperatures down to – 10° C in the upper layers. Wet slabs and sluffs fall when the snow is isothermal at the melting point. Densities are usually over 450 kg m−3and may reach over 600 kgm−3in slush layers supported by ice lenses.