Velocity, heat budget and mass balance at Anvers Island ice cap, Antarctic Peninsula

Abstract

General glaciological characteristics of a part of Anvers Island, Antarctic Peninsula, were studied during the summer of 1982. Ice thickness was calculated from gravity data. Net balance was determined by snow stratigraphy at two campsites and the equilibrium line altitude was estimated to be at 180m above sea level. A heat balance was assessed for Camp 1 (474m a. s. l.) in two ways by using different equations to estimate long wave and turbulent fluxes. Both calculations show that heat sources are approximately equal to heat sinks for the 12-day summer period. The main heat source is short wave radiation while the main sinks are evaporation and long wave radiation. A small amount of melting occurred during the period. Hand drilling down to 11m was carried out and several ice lenses were found. an evidence that meltwater refreezes as it percolates down due to sub-zero englacial temperatures. A mass balance was calculated for an area of 46.5(km)^2 by iso-balance curves. A positive net balance of 6×(10)^g・a^ was obtained. This result was comparable to that of 1965-1967 for a part of the ice cap of Anvers Island which included our study area.