George Clayton Kennedy

Background

George Clayton Kennedy was born on September 22, 1919 in Dillon, Montana, United States, the son of Clayton Tierny Kennedy and Maude Coley.

Education

Kennedy was educated by itinerant teachers, but at the age of sixteen he won a scholarship to Harvard University. There he received his Bachelor of Arts degree in geochemistry in 1940, his Master of Arts degree in geochemistry in 1941, and his Doctor of Philosophy degree in geology in 1946.

Career

Kennedy was a geologist at the Alaska branch of the United States Geological Survey from 1942 to 1945 and a physicist at the United States Naval Research Laboratory in Washington, D. C. , in 1945. He was a junior research fellow at Harvard from 1946 to 1949 and an assistant professor from 1949 to 1953. From 1953 to 1969, Kennedy was a professor of geology, and from 1969 to 1980 professor of geology and geochemical science, at the Institute of Geophysics and Planetary Sciences at the University of California at Los Angeles. He was an associate editor of Orchid Digest and vice-chairman of the Explorers Club (1967 - 1968).

He published on such topics as the hydrothermal solubility of silica, volcanology, contact metamorphism, solubility in the gas phase, problems in geochemistry, the effects of volatiles, thermal expansion at high pressure and the synthesis of large diamonds, and the physics of high pressures. Kennedy and his coworkers developed a popular and much-copied version of the oppose-danvils high-pressure apparatus, which he later abandoned in favor of a piston-cylinder apparatus capable of pressures up to 80 kilobars. He measured the pressure-volume-temperature relations of water-carbon dioxide mixtures and solutions, thereby providing petrologists and geochemists with data necessary for thermodynamic calculations for many equilibrium reactions. Along with his research associates Kennedy determined phase relationships in sodium chloride-water and silicon dioxide-water systems that became models for salt and silicate systems at high pressures.

The Kennedy law of melting resulted from the establishment and subsequent experimental verification of the relationship between volume change and temperature of melting. Kennedy applied his law of melting to the determination of the temperature of the Earth's outer core. He concluded that the core must have a partly subadiabatic temperature gradient and, therefore, that corewide convection was impossible. Based on contemporary models of convection in the core, the consequence of his conclusion was that the Earth could have no magnetic field. For a number of years attempts were made to solve the "Kennedy paradox"; models of convection in the core that began to emerge in the 1990's were consistent with Kennedy's thermal model.

Kennedy's calibration of the high-pressure scale provided standards used in laboratories worldwide and established targets for theoreticians concerned with extrapolation to pressures higher than those possible in Kennedy's laboratory. Until the final month of his life, Kennedy continued to carry out experiments that required the combined genius and skill of a physicist and a surgeon, yet were elegant in conceptual simplicity. He was capable of doing delicate measurements of utmost sensitivity within the confines of apparatus that sustained high pressures and temperatures.

Achievements

• Kennedy George achieved world-class status in several disciplines. He was remembered as one of the outstanding experimental geophysicists; one of his experiments resulted in the development of well-known Kennedy law of melting. He was also known internationally for his collections and knowledge of primitive art and orchids. He received a special award from the American Mineralogical Society in 1956 for his contributions to geological research.

Membership

In the late 1950's, Kennedy became a fellow of the American Mineralogical Society and the American Academy of Arts and Sciences and was a member of the Geological Society of America and the Society of Economic Geology.

Connections

Kennedy married Sally Slocum on October 1, 1951; they had three children and were later divorced. On May 11, 1968, he married Ruth Porter; they had no children.

Father:

Clayton Tierny Kennedy

Mother:

Maude Coley

Spouse:

Sally Slocum

Spouse:

Ruth Porter