First Glaciological Studies on the James Ross Island Ice Cap, Antarctic Peninsula

Abstract

AbstractA 10 m deep core and a 2 m pit were achieved in December 1977 on the ice cap of James Ross Island (Antarctic Peninsula) 3 km westward of the main dome at an altitude of 1 500 m. The 10 m temperature was −14.2°C. The core was cut into 106 samples which have been used for density, total β radioactivity, electroconductivity, and deuterium-content measurements. The age at the bottom of the bore hole has been estimated to be 1 965±1 year and a mean annual snow accumulation rate 37.7±3.0 g cm−2a−1is calculated over the last 13 years. By comparing our results with those obtained in other areas of the Peninsula, the climate of the upper part of James Ross Island seems to follow the climatic regime of the western coast. A preliminary chemical analysis of the pit samples leads us to conclude that the snow impurities are mainly sea-salt derived. The conductivity measurements show a clearly defined peak at the end of 1967 which could be linked with the volcanic eruption of the Deception Island volcano in December 1967. The interest of the studied location is discussed in view of further more extended glaciological investigations and particularly a possible coring to the bottom.