Donald L. Turcotte

2003 William Bowie Medal Winner
University of California


Donald L.Turcotte was awarded the Bowie Medal at the AGU Fall Meeting Honors Ceremony, which was held on 10 December 2003, in San Francisco, California. The medal honors “outstanding contributions to fundamental geophysics and for unselfish cooperation in research.”


“Few have contributed more to fundamental geophysics, or been better at encouraging others to contribute, than Donald L. Turcotte. Don trained as an engineer, receiving a Ph.D. in aeronautics and physics from the California Institute of Technology in 1958. After a year at the Naval Postgraduate School in Monterey, he joined the Cornell Graduate School of Aeronautical Engineering, rising to full professor. He established expertise on seeded combustion, magnetohydrodynamic and electrical phenomena in turbulent boundary layers, and shock waves, and authored a book, Space Propulsion and Statistical Thermodynamics, and co-authored a textbook, Statistical Thermodynamics.

“In 1965 he went on sabbatical to Oxford and returned an Earth scientist. The catalyst was Ron Oxburgh. Plate tectonics was just on the horizon, and Don joined his quantitative abilities and physical intuition with Ron’s skills and knowledge of geology to produce over the next decade a remarkable series of 24 papers that explored topics such as the many implications of the Earth’s thermal boundary layer, ridge melting, subduction zone volcanism, and intraplate tectonics and magmatism, and established the physical bases for many of the processes operating on our planet. Shifting to the Cornell Department of Geological Sciences in 1973, Don explored virtually every aspect of physical Earth geology and became an expert on planetary remote sensing and geophysical interpretation. He published over 150 papers on thermal subsidence in sedimentary basins, two-phase hydrothermal porous media convection, lithosphere flexure, cyclic sedimentation, and stick-slip earthquakes and the lithospheres and mantles of the other planets. He worked and published with outstanding students and colleagues including Ken Torrance, Gerald Schubert, David Spence, Marc Parmentier, Bill Haxby, John Ockendon, Kevin Burke, Jud Ahern, Steve Emerman, and Charlie Angevine. In 1982 he published Geodynamics with Jerry Schubert, a book that became the primary reference in the field.

“In 1985 Don was introduced to fractals by Bob Smalley, and his intellect engaged. He showed how fractals and chaos apply to almost every Earth process and at last explained why geologists place rock hammers in their photographs. In 1992 he published Fractals and Chaos in Geology and Geophysics, a book that became the primary Earth sciences reference in this new field. In 2001 he published a comprehensive book on mantle convection with Jerry Schubert and Peter Olson.

“Don has been a member of innumerable academy committees, editorial boards, and working groups. He is a past president of the Tectonics Section of the AGU, past chair of the Geophysics Section of the National Academy of Sciences, and was chair of the Department of Geology at Cornell for 9 years. Few in the profession will not have interacted with Don in one capacity or another. All appreciate his managerial style and ability to routinely turn mountains into molehills.

“Most amazing is how with such apparent ease and equanimity one person could be so prolific, so effective in applying fundamental physical and chemical principles to understand the Earth and planets, and so successful in establishing long-term and productive collaborations. Few deserve an award honoring ‘outstanding contributions to fundamental geophysics and unselfish collaboration in research’ more than Don Turcotte.”

—LAWRENCE M. CATHLES, Cornell University, Ithaca, N.Y.


“I would like to thank Larry Cathles for his kind words. I am very honored to have been selected for this recognition, but must emphasize that all my efforts have been joint with colleagues, postdocs, graduate students, and undergraduates.

“My career in geophysics over the past 38 years was really defined by two chance meetings. The first was with Ron Oxburgh at Oxford in the fall of 1965. I was on sabbatic leave in engineering and was asked to discuss mantle convection with Ron, a young geology faculty member. He had recently arrived at Oxford from Princeton and was a strong advocate of mantle convection and continental drift. We jointly developed a theory of boundary-layer convection for the mantle which is pretty much the standard model today. Ron and I went on to publish a series of papers maximizing a collaboration between a geologist who didn’t know anything about equations and an aerospace engineer who didn’t and—doesn’t—know one rock from another.

“The second chance meeting was with Jack Oliver at the long gone AGU ‘Smoker’ at the 1967 Spring Meeting in Washington. I was deeply involved in the transfer of Cornell’s Geology Department from the College of Arts and Sciences to the Engineering College and learned that Jack might be available to take a leadership role. Fortunately for all, this worked out and the rest is history. Jack built a wonderful department along with COCORP, and I spent an absolutely wonderful 30 years participating in the adventure.

“I must recognize stimulating and productive collaborations with Ron Oxburgh, Jerry Schubert, Ken Torrance, David Spence, Hilary and John Ockendon, Claude Allegre, John Rundle, Volodya Keilis-Borok, Bill Newman, and Andre Gabrielov among others. I must also recognize the absolutely essential contributions of my graduate students, including Albert Hsui, Marc Parmentier, Bill Haxby, Charlie Angevine, Ray Willemann, Jud Ahern, Steve Emerman, Pat Kenyon, Louise Kellogg, Jie Huang, Cheryl Stewart, Algis Kucinskas, Bruce Malamud, Jon Pelletier, Gleb Morein, and Robert Shcherbakov.

“I found my colleagues at Cornell to be most stimulating. This was particularly true of our luncheon group. I joined this ongoing luncheon group when I joined the Cornell faculty in 1959, and it continues after my departure from Cornell this year. There were certain rules: go to lunch at 11:30, eat quickly, and enjoy wide-ranging discussions over coffee. Regular participants included Bryan Isacks, Sue and Bob Kay, Larry Cathles, Jack Bird, and Syd Kaufman. We provided solutions to a wide range of problems both scientific and political from an extremely diverse range of viewpoints.

“I will conclude with the following comment. When I retired from Cornell in January of this year for the University of California at Davis, the position at Davis was half time. My wife keeps asking me why a half-time position requires that I go into the office seven days a week, often by 7 A.M. The answer is simple. Doing geophysical modeling isn’t work, its fun, and its just as much fun today as it was 35 years ago.”

—DONALD L. TURCOTTE, University of California, Davis