First data on the climate variability in the vicinity of Vostok Station (central Antarctica) over the past 2,000 years based on the study of a snow-firn core

Central Antarctica is characterized by a crucial lack of information on climate variability during the late Holocene. The study of firn cores obtained from the central part of the East Antarctic Ice Sheet is essential for the reconstruction of the paleoclimatic conditions at the continental and regional scales over the past 2,000 years (the Late Holocene). Based on glaciological and isotopic data from the shallow VK16 core drilled in the vicinity of Vostok Station over the periods of the 62th (2016-2017) and 63th (2017-2018) summer seasons of RAE, climatic characteristics have been reconstructed for the period 216 BC - 2010 AD. Studies of the VK16 core were carried out in two stages: firn density and electrical conductivity measurement (ECM), as well as sampling, was performed in the glaciological laboratory of the 5G drilling complex (Vostok Station) soon after the firn recovery, while the isotopic composition of the core samples was measured by a Picarro L-2120i laser analyzer in the Climate and Environmental Research Laboratory of AARI. In the ECM profile of the core, we discovered 14 absolute age markers (layers containing the products of known volcanic eruptions). These markers have allowed us to develop a robust chronostratigraphic scale for this core. We have shown that the main feature of the Late Holocene climate in this part of Antarctica is that the near-surface air temperature remained essentially constant throughout the whole time period under consideration. At the same time, the snow accumulation rate varied significantly around a mean value of 1.83 g cm-2 year-1, while the last 200 years were characterized by the highest snow accumulation rate, equal to 2.08 g cm-2 year-1. In this paper, we describe methods for studying firn cores, which can be useful for further research, and present first preliminary data on the climate variability in the vicinity of Vostok Station during the late Holocene.

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