Snow Stratigraphic Record at South Pole: Potential for Paleoclimatic Reconstruction

Abstract

An extensive investigation of the visible stratigraphy, microparticle concentration, liquid conductivity, oxygen isotopes and beta-radioactivity was conducted in pits excavated at Amundsen-Scott South Pole station. The objectives of the investigation were to assess the spatial representativeness of the geochemical and physical records preserved within the snow strata and to ascertain the temporal resolution which can be obtained from such ice-core records. Accurate interpretation of the time scale and reconstruction of climatic conditions from these time series requires (1) the analysis of as many stratigraphic parameters as possible and (2) the synthesis of data from a suite of cores in the study area. For periods of 10 a or less, regionally representative accumulation rates cannot be obtained from annual accumulation time series reconstructed at a single site. Although the microparticle concentrations, liquid conductivity and oxygen isotopic abundances all exhibit a seasonal cycle in the firn, the construction of an accurate time scale requires all three parameters in conjunction with the beta-radioactivity. Absolute dating will be impossible for cores from South Pole where entire accumulation years may be missing. Nevertheless, for East Antarctica, where accumulation rates are low (<0.1 m a−1 water equivalent), the good temporal resolution and the preservation of a distinct annual signal in some geochemical parameters makes the South Pole a very attractive site for deep ice-core drilling.