SPATIAL DISTRIBUTION OF THE SNOW ACCUMULATION RATE ALONG THE ICE FLOW LINES BETWEEN RIDGE B AND LAKE VOSTOK

Abstract

During the 45 th –57 th Russian Antarctic Expeditions (1999–2012) an intensive program of glaciological and geophysical observations have been carried out in the region between the subglacial Lake Vostok and the Ridge B, Сentral Antarctica. In this work we present the instrumentally obtained snow accumulation data along the northern ( NVFL ) and southern ( VFL ) ice flow lines passing through the Lake Vostok. The mean accumulation rate at the NVFL and VFL profiles is 29–37 kg m -2 yr -1 and 21–24 kg m -2 yr -1 , respectively. Thus, this region is characterized by a strong latitudinal gradient of the snow accumulation rate, while the longitudinal one is an order of magnitude less. The spatial distribution of the accumulation rate along the VFL is characterized by a sharp variability attributed to the snow re-deposition due to the wind interplay with the local glacier surface slope anomalies. The new data on the stable water isotope concentration ( 18 O) along the VFL profile are also presented.