INTERNATIONAL GEOPHYSICAL YEAR

INTERNATIONAL GEOPHYSICAL YEAR, eighteen months (1 July 1957–31 December 1958) of geophysical observations by about 30,000 scientists and technicians representing more than seventy countries. The extension of this program for an additional year (until 31 December 1959) was officially called International Geophysical Cooperation (IGC), but that period is generally included in the term "International Geophysical Year" (IGY).The IGY and IGC attempted simultaneous observations in eleven fields of earth, near-earth, and solar physics: aurora and airglow, cosmic rays, geomagnetism, glaciology, gravity, ionospheric physics, latitude and longitude determination, meteorology, oceanography, seismology, and solar activity. The IGY oversaw the launching of the first artificial earth satellites, inaugurating the age of space exploration.

International cooperation in science began in the 1830s with the networks of scientific observers organized by Karl Friedrich Gauss in Germany to observe and record geomagnetic changes, and by W. Whewell and Sir John W. Lubbock in England to make tidal observations. Because observations in high northern latitudes could not be made routinely, Lt. Karl Weyprecht of the Austrian Navy organized the First International Polar Year in 1882–1883, during which scientists and military men from ten European countries and the United States operated twelve stations in the Arctic and two in the Antarctic. The American stations were at Point Barrow, Alaska, and at Grinnell Land in the Canadian Arctic. The rescue of the latter's observers (under army Lt. A. W. Greely) is famous in the annals of polar exploration. Fifty years later the Second International Polar Year (1932–1933) saw fourteen countries (twelve from Europe, plus the United States and Canada) occupy twenty-seven stations, again mostly in the Arctic. Of the scientific publications that resulted, more came from the United States than from any other country.

By 1950, the rapid advances in geophysics and the need to restore the international network of scientists that had been ruptured by World War II led Lloyd V. Berkner of the United States to propose another international polar year to be held only twenty-five years after the previous one, in 1957–1958.The international scientific bodies to whom he referred his proposal, organized under the umbrella International Council of Scientific Unions, broadened it to include the entire earth; thus the IGY replaced its predecessors' limited programs with a comprehensive program of observations in fields where data recorded simultaneously at many places could yield a picture of the whole planet. Scientists occupied more than 2,500 stations worldwide at a cost of about $500 million.

Two of the most prominent achievements of the IGY were the discovery of the Van Allen radiation belts and the calculation of a new, pear-shaped model of the shape of the earth. Both these results came from rocket-launched satellites, the IGY's most spectacular new feature. So successful was the IGY that it has been followed by a number of other cooperative research programs, including the International Year of the Quiet Sun (1964–1965), the International Hydrological Decade (1965–1975), and the International Decade of Ocean Exploration (1970–1980).

BIBLIOGRAPHY

International Council of Scientific Unions. Annals of the International Geophysical Year. London, New York: Pergamon Press, 1957–1970. Sullivan, Walter. Assault on the Unknown: The International Geophysical Year. New York: McGraw-Hill, 1961.

Wilson, J. Tuzo. I.G.Y.: The Year of the New Moons. New York: Knopf, 1961.

Harold L.Burstyn/a. r.; c. w.

See alsoGeophysical Explorations ; Greely's Arctic Expedition ; Observatories, Astronomical .

International Geophysical Year (IGY), 18-month period from July, 1957, through Dec., 1958, during a period of maximum sunspot activity, designated for cooperative study of the solar-terrestrial environment by the scientists of 67 nations. The only prior combined international scientific efforts took place during the Polar Years of 1882 and 1932. Discoveries were made in the fields of cosmic ray research, climatology, oceanography , and the nature of the earth's atmosphere and magnetic field . Earth satellites (see satellite, artificial ) launched by the United States discovered the Van Allen radiation belts , the influx of charged solar particles detected believed to be responsible for northern and southern polar auroras. Soundings of the world's oceans revealed new information about the physical features on the ocean floor. Seismically active rifts along the summits of mid-oceanic ridges were identified. IGY scientists conducted extensive studies of deep ocean currents and developed better gravity measurements for mineral exploration. The major programs of IGY were continued from Jan., 1958, to Jan., 1959, as the International Geophysical Cooperation. Also connected to IGY was the International Years of the Quiet Sun, an international cooperative program during 1964 to 1965, that focused on solar-terrestrial phenomena during a quiet sun, or near sunspot minimum. The IGY was the largest and most important international scientific effort to that date. One of its many later ramifications was the setting aside of Antarctica as a nonmilitary region to be used for international scientific purposes alone. Antarctica has become a base for collecting meteorological data, including information on the presence and effects of moisture, carbon dioxide, and electrified particles on the atmosphere, and the general circulation of the atmosphere.

Bibliography: See S. Chapman, IGY: Year of Discovery (1960); W. Sullivan, Assault on the Unknown (1961); J. T. Wilson, IGY: The Year of the New Moons (1961).

International Geophysical Year (IGYM) An 18-month period, from 1957July to the end of 1958, in which world-wide collaborative observations were made to study the connection between solar flares, geomagnetic disturbances, radio fade-outs, and particle emission from the Sun. The IGY was designed to coincide with maximum sunspot activity, which turned out to be the largest recorded since the invention of the telescope, and resulted in a greatly improved picture of solar–terrestrial relations. Sputnik 1, the first artificial satellite, was launched during the IGY by the Soviet Union.

International Geophysical Year see International Geophysical Year .

IGY Abbr. for International Geophysical Year.

IGY International Geophysical Year (1.7.57 to 31.12.58)