High-resolution 900 year volcanic and climatic record from the Vostok area, East Antarctica

摘要

Ion chromatography measurements of 1730 snow and firn samples obtained from three short cores and one pit in the Vostok station area, East Antarctica, allowed for the production of the combined volcanic record of the last 900 years (AD 1093a??2010). The resolution of the record is 2a??3 samples per accumulation year. In total, 24 volcanic events have been identified, including seven well-known low-latitude eruptions (Pinatubo 1991, Agung 1963, Krakatoa 1883, Tambora 1815, Huanaputina 1600, Kuwae 1452, El Chichon 1259) found in most of the polar ice cores. In comparison with three other East Antarctic volcanic records (South Pole, Plateau Remote and Dome C), the Vostok record contains more events within the last 900 years. The differences between the records may be explained by local glaciological conditions, volcanic detection methodology, and, probably, differences in atmospheric circulation patterns. The strongest volcanic signal (both in sulfate concentration and flux) was attributed to the AD 1452 Kuwae eruption, similar to the Plateau Remote and Talos Dome records. The average snow accumulation rate calculated between volcanic stratigraphic horizons for the period AD 1260a??2010 is 20.9 mm Hsub2/subO. Positive (+13%) anomalies of snow accumulation were found for AD 1661a??1815 and AD 1992a??2010, and negative (a??12%) for AD 1260a??1601. We hypothesized that the changes in snow accumulation are associated with regional peculiarities in atmospheric transport.