Turekian joined the Yale faculty in 1956 as its first geochemist. Over the next five decades, his trademark became the inventive use of trace elements, natural radioactive elements, and radiogenic isotopes for understanding processes of the Earth, its atmosphere, and oceans.
He shed light on acid rain, cosmic dust flux, sediment accumulation, the global transport of metals through the atmosphere, the circulation of Long Island Sound, the composition of the continental crust, and the origin of the solar system, among other phenomena. His research bolstered the idea that a giant meteorite strike led to the extinction of the dinosaurs, and he advanced new methods for testing models of atmospheric circulation and identifying art forgeries.
“Karl Turekian was at the forefront of expanding the scope of questions that could be addressed by geochemistry and developing new techniques to answer them,” said Bill Graustein, who studied under Turekian and remained a close friend. “He consistently used his encyclopedic knowledge of the study of the Earth to take techniques developed in one area and apply them to unsolved problems in other areas.”
Along the way, Turekian mentored generations of scientists, both in the laboratory and in free-flowing coffee hour chats that “launched countless scientific careers and indeed set the course of geochemistry that carries forward today,” said Jay Ague, the current chair of Yale’s Department of Geology & Geophysics.
Turekian fondly recalled dozens of former students and fellow researchers by name in a 2005 autobiographical piece published in the Annual Review of Earth and Planetary Science. “My undergraduate and graduate students brought excitement to my life at Yale then and this has continued to the present day,” he wrote.
Born Oct. 25, 1927, Karl Karekin Turekian was raised in New Jersey and the Bronx, the son of Armenian immigrants and genocide survivors. He served in the U.S. Navy, received his bachelor’s degree from Wheaton College in 1949, and then, in 1955, earned one of the first doctorates in geochemistry awarded by Columbia University. He joined the Yale faculty the next year and married his wife, Roxanne, in 1962.
Over a long career, Turekian — who at the time of his death was Sterling Professor of Geology & Geophysics Emeritus, Yale’s highest faculty rank — wrote hundreds of journal articles and five books, including “Oceans,” “Man and the Ocean” (with Yale geologist B.J. Skinner), “Chemistry of the Earth,” “Oceanography” (with C. Drake, J. Imbrie and J. Knauss), and “Global Environmental Change.”
Turekian served in editorial positions of eight scholarly journals and in a wide variety of administrative roles at Yale. He was chair of the Department of Geology & Geophysics for most of the 1980s; curator-in-charge of meteorites and planetary science at the Peabody Museum of Natural History; director of the Center for the Study of Global Change; and director of the Yale Institute for Biospheric Studies.
A member of Yale’s Elizabethan Club, Turekian also was an executive fellow at Yale’s Berkeley College.
He was a member of the National Academy of Sciences and a fellow of the American Academy of Arts and Sciences, among other learned societies, and received many honors during his career. These included the Goldschmidt Medal of the Geochemical Society, the Maurice Ewing Medal of the American Geophysical Union and the Wollaston Medal of The Geological Society of London, and, from the Yale College Phi Beta Kappa chapter, the William Clyde DeVane Medal for distinguished teaching and scholarship.
Turekian is survived by his wife, Roxanne; two children, Karla Ann Turekian and Vaughan Charles Turekian; a daughter-in-law, Heather Leigh Turekian; two grandchildren, Aleena Marie Turekian and Charles (“Chip”) Henry Turekian; and many cousins, nieces, and nephews. A private graveside service will be held at Grove Street Cemetery in New Haven. A celebration of his life will take place at a later date.
“The world has lost one of the greatest geoscientists who ever lived,” said Ague. “His influence is so large it is impossible to measure.”