Chemical characterization of the last 250 years of snow deposition at Talos Dome (East Antarctica)

Abstract

High-resolution chemical records of main and trace ionic components of snow precipitation over the last 250 years were obtained by analysing the first 36 m of a firn core drilled at Talos Dome, a dome located in the ice divide between northern Victoria Land and Oates Land (East Antarctica Pacific Ocean/Ross Sea sector). The concentration/depth profiles of some relevant chemical parameters are discussed on the basis of a previous stratigraphic dating, set up following the seasonal signatures of non-sea-salt (nss) sulphate deposition and synchronised by using tritium and volcanic temporally known horizons. Particular attention is paid to the study of the temporal trends of the sea spray components (Na⁺, Cl⁻, Mg²⁺) and S and N cycle compounds () to understand the main sources, transport mechanisms and depositional processes of these compounds at the deposition site. Good correlations between the sea spray markers show that the primary marine contribution is relevant, though Talos Dome is located at a relatively high altitude (2316 m a.s.l.) and far from the coast line (about 250 km). The study of the snow chemical composition and of the recent (for the last few centuries) atmosphere/snow relationship at Talos Dome is important as a preliminary survey at this station, which will probably be chosen for a deep ice coring project.

Keywords:

• Ion chromatography
• Chemical analysis
• Firn core
• Talos Dome
• Antarctica

Acknowledgements

This research was carried out within the framework of Projects on Chemical Contamination and Glaciology of the Programma Nazionale di Ricerche in Antartide (PNRA) and was financially supported by ENEA through a co-operation agreement with the Università degli Studi di Milano-Bicocca. This work is a contribution from the Italian branch of the ITASE project. The authors wish to thank all members of the 1996 ITASE traverse.

This work is a contribution to the European Project for Ice Coring in Antarctica (EPICA), a joint ESF (European Science Foundation)/EC scientific programme, funded by the European Commission and by national contributions from Belgium, Denmark, France, Germany, Italy, The Netherlands, Norway, Sweden, Switzerland and the United Kingdom. This is EPICA publication no. 82.