(1930-1993) Australian Geochemist
Alfred (Ted) Ringwood is one of the true giants of geology for many reasons. He is best known for his solution of a fundamental problem in geology, the transition between the upper and lower mantle. Seismologists had known for many years that seismic velocities in the mantle increase rapidly between 400- and 900-km depth. This transition zone was speculated to be the result of the crushing down of mineral structures (phase transformations) as the result of the extreme pressure. Such reconfiguring of atoms would be similar to the transformation of graphite to diamond with pressure. The problem was that no laboratory in the world could replicate those conditions. Ringwood overcame that problem by synthesizing an olivine structured mineral (olivine is the common mineral in that part of the mantle) except he used the element germanium instead of silicon (the element in natural olivine) in the structure. Because germanium has a smaller atomic radius than silicon but otherwise fits all of the other requirements, it would transform to the new structure at low enough pressures to be within the experimental range at the time. His experiments showed that the olivine structure would convert to a spinel structure and predicted by extrapolation that it should occur in natural olivine at 400-km depth. Later seismic studies found that indeed there is a seismic discontinuity at 400 km and later experimental work with more sophisticated equipment showed that Ringwood was correct. Continued research by Ringwood showed that pyroxene, the other major mantle mineral, converted to garnet structure between 400 and 650 km and that the spinel structure converted to a “perovskite” structure at still greater depths using his experimental models. Papers on this work include “Phase Transformations in the Mantle,” and several other similar titles.
Ringwood then attacked the problem of how basaltic magma was generated in the mantle at the mid-ocean ridge. He bucked traditional wisdom and proposed that there was a strange composition substance in the mantle called “pyrolite” from which basalt was derived. He wrote a classic paper on the topic entitled “The Genesis of Basaltic Magmas” in 1967. The pyrolite model was subsequently disproved but the idea that different compositions of basalt are generated at different depths, which was also incorporated in the model, is still unquestioned and considered a major contribution to the science.
In addition to these gargantuan issues, Ring-wood also had several other areas of interest. He gave new insights to the composition of the core of the Earth which are still accepted. He proposed models for the chemical evolution of the Earth, other planets, and meteorites. He proposed models for the composition and origin of the Moon while working on the Apollo lunar missions with NASA. He championed the idea that the Moon may have been spiralled off of the early Earth as the result of a giant impact. Finally, he applied his geochemical expertise to nuclear waste disposal. To each of these highly varied topics he made contributions to the science which still set the standards today.
In recognition of his accomplishments, Ring-wood received the Antonio Feltrinelli Prize in 1991 from the Academia Lincei in Rome, the oldest scientific society in the world. Galileo was the head of the society in its early years. The Feltrinelli Prize is similar to the Nobel Prize but awards only one prize per year in all fields. It has been awarded to the likes of Thomas Mann, Igor Stravinsky, Albert Sabin, and Georges Braque. The previous geologist to receive the prize was harry h. hess in 1966, another giant of geology.
Ted Ringwood was born in Kew, near Melbourne, Australia, on April 19, 1930. He attended Hawthorn West State School, Geelong Grammar School, and Melbourne High School as a youth in Melbourne. He enrolled in the University of Melbourne with a Trinity College Resident Scholarship and a Commonwealth Government Scholarship. He graduated with a bachelor of science degree in geology with honors in 1951 and a master of science degree with honors in 1953. He continued at the University of Melbourne to earn a Ph.D. in 1956 at 26 years of age. He became a research fellow at Harvard University in 1957. During this time he made several visits to Sweden to study meteorites and met Gun Carlson, whom he married in 1960. They had two children. He returned to join the faculty at the Australian National University in 1959, where he remained for the rest of his life. He served as director of the Research School of Earth Sciences from 1978 to 1983. Ringwood died of lymphoma on November 12, 1993, at the age of 63.
Ted Ringwood led an extremely productive career. He was an author of more than 300 publications, including articles in international journals and professional volumes as well as books. Many of these papers are benchmark studies on processes, properties, and compositions of rocks in the interior of the Earth. Many appear in prestigious journals like Science and Nature. He also wrote two widely acclaimed books, Composition and Petrology of the Earth’s Interior and Origin of the Earth and Moon, and even had several patents for high-level nuclear waste disposal. Ringwood received honors and awards too numerous to list completely. He was a fellow of the U.S. National Academy of Sciences and the Australian Academy of Sciences. He received an honorary doctorate from the University of Gottingen, Germany. He received the Mineralogical Society of America Award, the Werner Medaille from the German Mineralogical Society, the Arthur L. Day Medal from the Geological Society of America, the Bowie Medal and the Harry H. Hess Medal from the American Geophysical Union, the Arthur Holmes Medal from the European Union of Geosciences, the Wollaston Medal from the Geological Society of London, the Goldschmidt Award from the Geochemical Society, the Inaugural Rosentiel Award from the American Association for the Advancement of Science, and the Matthew Flinders Lecture and Medal and the J.C. Jaeger Medal from the Australian Academy of Science, among many others. He served numerous endowed lectureships from the most prestigious organizations. He also performed service to the profession like serving as the vice president for the Australian Academy of Science, for example, but it is also too extensive to list here.
