The Vostok Venture: An Outcome of the Antarctic Treaty

Abstract

INTRODUCTIONPolar ice sheets and glaciers contain well-ordered archives of ancient ice that fell as snow, years to millions of years ago. With an ice blanket of more than 3 km thick and an annual precipitation rate comparable to that from hyperarid regions (equivalent to 2-5 cm water annually), the slow-moving East Antarctic plateau has considerable potential for providing a long-undisturbed ice sequence. Because of the remoteness of inland sites along with the harsh weather conditions, exploration and deployment of scientific traverses or deep ice core drilling operations require coordination of considerable logistic support, technical, and scientific skills.Vostok station was settled at the time of the International Geophysical Year (IGY) by the Soviet Union and is a location 1,400 km from the coast at 3,488 m above sea level altitude, with an annual temperature of -55°C. Thanks to the Antarctic Treaty, which promoted the international collaboration, the study of a 2-km-deep ice core revealed the close link between temperature and atmospheric CO 2 over the last 150,000 years. This fact soon revealed the climate issues caused by increasing anthropogenic emissions of greenhouse gases.The ice composition and impurities and the gases trapped in air bubbles provide a unique history of the past climate change and environmental and atmospheric composition. By reaching 3.4 km depth, the climate record was extended back 400,000 years, confirming the close climate-greenhouse gas relationship. This link is now further extended over 800,000 years.At the base of the ice sheets the geothermal flux warms the ice, up to the melting point in some places. The water produced accumulates at the interface with the bedrock to form a lake. This is the case in the region of Vostok, where a giant lake lies under the station. Ice core drilling penetrated an ice massif of refrozen lake water at 3.6 km depth. The recovery of frozen lake samples opens new fields for research, especially for the search for life in this very extreme environment, which may help the search for life elsewhere.