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ANTARCTICA: THE CONTINENT FOR SCIENCE

ice past studies unique

The Antarctic is a continent of extremes, one of which is that its inhabitants are almost exclusively scientists. The unique properties of this remote and ice-bound continent have made it a natural laboratory for, in particular, the earth sciences, life sciences, space science and environmental studies.

The place names of Antarctica are a record of its discoverers – men like Bellingshausen, Weddell, Dumont d’Urville and Amundsen. Most were adventurers and explorers; others such as could be considered scientists through their additional scientific observations. The exploration of Antarctica continued through the efforts of men such as Shackleton, Byrd and Mawson in the early 20th-c, the so-called ‘heroic era’ characterized by the outstanding physical efforts of individuals.

Routine scientific studies largely began in 1957 when the International Geophysical Year provided the impetus for many nations to establish permanent bases and year-round scientific programmes, as well as convenient means of adding credibility to territorial claims. The logistics of simply maintaining bases has meant that most Antarctic science since has been a team effort. Most such work has concentrated on mapping the geology and geophysics of the Antarctic, and studies of the unique and abundant marine life. While richly rewarding, such studies have been of limited wider relevance.

Ironically it has been the most obviously unique feature of the Antarctic that has been the most informative about the rest of the world – the ice sheet which covers 98% of the continent. Ice cores drilled into the 4 km thick ice sheet preserve a wealth of climatic information covering the past 150 000 years, revealing information about air temperature, precipitation levels, atmospheric composition and CO2 levels, meteorite falls, volcanic activity through the deposited acids and dust, and past solar flares through the resulting deposits of beryllium-10. (This is formed when high-energy particles associated with solar flares act on nitrogen in our upper atmosphere to give beryllium, later deposited on Earth.) The continuity and purity of Antarctic ice cores has thus provided one of the most comprehensive records of past climate available. Analysis of more recent snowfalls, over a scale of a few years, has provided unique baseline data on man-made pollutants such as pesticides, lead from car exhausts, fallout from bomb tests, etc, stretching back to before the industrial revolution.

One of the most recent discoveries made in the Antarctic has been the most dramatic, possibly so important that the whole future of human existence may depend upon it. In 1984 observed a 40% depletion in ozone levels in the stratosphere above the Antarctic. Constant studies since have shown that ozone levels around both the South and North Pole have continued to drop alarmingly. Since the ozone layer protects life from the more harmful effects of the Sun’s ultraviolet radiation, its disappearance may well have dramatic and severe effects for all life forms over the coming years. The cause has been identified as the manufacture and use of chlorofluorocarbons (CFCs) during the past 20–30 years, and Farman’s discovery directly resulted in worldwide government action to limit the use of CFCs.

In 1995 a dramatically large iceberg (2888 km 2 /1115 sq mi) broke away from N W Antarctica into the Weddell Sea: a major event that may link with a rise of 2.5°C in average temperatures during the last 50 years.

As concern grows about climatic change and global environmental issues, the Antarctic is likely to become an increasingly important laboratory for studying past climate through deep drilling into the ice sheet, where unique information on past atmospheric composition, temperature and climate is to be found. A major international drilling programme was started in 1996. Studies of whales and ice sheet melting and iceberg formation also give clues about present-day environmental change.

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