Danny Michael Rye

Professor of Earth and Planetary Sciences

Danny Rye, A.B. Occidental College, Ph.D. University of Minnesota, faculty member at Yale since 1975: You have been a prominent innovator in the applications of isotope systems to earth-system processes.

Your scientific career has centered on the geologic applications of isotopic ratios of chemical elements in rocks, subsurface fluids, and Earth’s atmosphere. Techniques pioneered by you and your students in your mass-spectrometer facilities in Kline Geology Laboratory – to calculate the minute variations that can reveal the temperature and salinity of the ancient oceans, the source of fluids that drive metamorphic reactions deep in Earth’s crust, and the life history of the marine mollusk Nautilus – have given technical and interpretive insight to a generation of geochemists worldwide. 

A key factor in your research is a deep understanding of thermodynamics in geological chemical reactions. Isotope geochemists often interpret rock formation from equilibrium model systems. You demonstrated, on the other hand, how the kinetics of reactions helped to explain why change in geologic systems often occurs rapidly when temperature and pressure “overstep” far from predicted phase transitions. This gave important information about earthquakes, which may be one consequence of rapid dehydration associated with thermal overstepping.

Another key impact of your career has been the development of techniques and instrumentation in isotopic measurements. As a young scientist you blew your own glass tubing, and found ways to improve the precision of your measurements beyond the specifications of standard mass spectrometers, leading the manufacturers to consult you for tips on upgrading their equipment. You are not attached unduly to artisanal methods, however. At the turn of the twenty-first century you developed the stable-isotope laboratory for Yale’s Institute for Biospheric Studies, sparing few opportunities for automation and technological edge, benefiting fellow faculty in environmental sciences, across Yale’s departments and schools.

Since 1987 you have served as editor of the American Journal of Science, founded by Yale professor Benjamin Silliman in 1818, carrying on that distinguished tradition. You oversaw the modernization of the journal, transitioning it from print-only to online access and managing the business and technical sides with equal dedication.

Your chairmanship of the department – then known as Geology and Geophysics –  during a critical 1997-2003 transition is especially notable. You reacted to a wave of deaths, departures, and anticipated retirements by turning more than half the department faculty slots into key senior appointments in geophysics and paleontology, overseeing the appointment of a cadre of junior faculty across the research groups, and thereby boosting your department’s international standing for decades. For this, as for so much else, your department owes you gratitude and tribute.