Since Antarctica is virtually untouched by civilization and has little animal and plant life, it serves as an ideal natural laboratory for the geophysical sciences. During the International Geophysical Year, 1957-58, 12 nations cooperated in beginning a thorough investigation of the south polar region. This undertaking contributed to the creation of the Antarctic Treaty of 1959; in addition to postponing territorial claims, the 12 signatory nations agreed to use the region jointly for peaceful and scientific purposes only. Other nations have subsequently joined in the research work. In 1988 the treaty nations signed an agreement that would govern development of all natural resources in Antarctica.
Exploratory studies of Antarctica's surface are now largely complete, and investigations have turned to the natural processes at work in the atmosphere, the ice, and the sea.
Extensive geological studies provide a general outline of the region's geology and support the theory of plate tectonics. (See Geology, subtitle Physical Geology: Plate Tectonics.) Investigations indicate Antarctica was once part of ancient Gondwanaland, a giant landmass that began breaking up and drifting apart some 125,000,000 years ago. Eventually, Australia, South America, Africa, the Indian subcontinent, and Antarctica were formed. Of special geological interest are the potential mineral and petroleum resources of the continent and the adjoining seabed. Fossils and exposed rock formations and coal seams provide clues to the continent's geological past. At one time there was no ice in Antarctica, and trees and large animals flourished.
Much of the glacial research in Antarctica has centered on the extent of the ice sheet and its surface characteristics, such as temperature and snow accumulations. Under increasing study, using such techniques as radio-echo sounding and ice-coring, is the internal nature of the ice. Scientists have also been trying to determine the age of the ice; the ice of East Antarctica is believed to be as much as 25,000,000 years old, while that of West Antarctica is much younger.
Using ground instruments, weather balloons, and satellites, meteorologists make detailed observations of the air of Antarctica. They measure humidity, temperature, air pressure, wind speed and direction, precipitation, radiation, and the ozone and carbon dioxide content of the atmosphere. With this information they attempt to determine the effect of Antarctic weather on the weather elsewhere. Observations in the late 1980's revealed widespread seasonal reductions in the ozone concentrations over Antarctica. (See Ozone.)
Because Antarctic waters circle the globe without being interrupted by a landmass, they are ideal for studying waves and the chemical and physical properties of seawater. They also provide information on ocean currents and the temperature variations of the world's oceans.
The presence of the south geomagnetic pole and the relative absence of radio-frequency noise (due to a scarcity of thunderstorms) make Antarctica particularly suitable for studying auroras, the ionosphere, cosmic radiation, the sun, the earth's magnetic field, and many other phenomena.