Robert Coe

Earth and Planetary Sciences Department – University of California Santa Cruz

2016 John Adam Fleming Medal Winner

Robert Coe was awarded the 2016 John Adam Fleming Medal at the AGU Fall Meeting Honors Ceremony, held on 14 December 2016 in San Francisco, Calif. The medal is for “original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and/or related sciences.”


Robert Coe is a ­­­world-­­­renowned scientist who has made significant contributions to several broad areas of geomagnetism and paleomagnetism. His scientific accomplishments have illuminated the research of many who work in areas ranging from geomagnetism and paleomagnetism to volcanology, geochemistry and petrology, and tectonophysics.

Coe is one of the pioneers in paleointensity determination. In the 1960–1970s Coe singularly developed a means of more accurately measuring the intensity of the ancient field recorded in rocks. This method, which bears his name, is now the gold standard of all paleointensity methods. Along the way he has produced many of the most reliable paleointensity values that we have. His most cited Journal of Geophysical Research (JGR) papers are still the bedrock references for anyone attempting to do the paleointensity work.

Coe has made significant contributions to the understanding of geomagnetic secular variation, including magnetic field reversals. Coe was one of the first paleomagnetists to use and realize the potential of geodynamo models as a tool to better understand observations of geomagnetic field behavior. He has teamed up with other ­­world-­class scientists, such as Gary Glatzmaier and Peter Olsen, to combine paleomagnetic results with dynamo theory. For example, he and his colleagues have shown that the reversal rate of the geomagnetic field can be significantly affected by lateral changes in the heat flux through the ­­core-­mantle boundary.

Coe has also made seminal contributions to the studies of tectonics. He and his students have carried out paleomagnetic projects in various tectonic settings, over scales ranging from small fault blocks to cratons. These works have led to new ideas about how ­­large-­scale continental collisions occur.

In the area of service, Coe’s record is every bit as exemplary as it is in research and teaching. He has served as editor for JGR and the Journal of Geomagnetism and Geoelectricity, as president of AGU’s Geomagnetism and Paleomagnetism section, and as a member of numerous national and international science panels and advisory boards.

Coe’s unwavering generosity in sharing his time, knowledge, and other resources extends to both colleagues and students. He has set a standard of integrity and professional commitment that is well respected in our community. In recognition of his outstanding contributions to the development of paleointensity methodology and scientific achievements in tectonophysics and geodynamo research, Coe is thoroughly deserving of the John Adam Fleming Medal.

—Rixiang Zhu, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China


Many thanks to AGU for this honor, to my students and many colleagues around the world for their friendship and collaboration, and to my wife and children for their support and inspiration. Looking back 60 years to when I first entered college, I realize that I’ve been very fortunate. I had no idea I would become a scientist, only that I was searching for understanding and meaning deeper than myself. After a year’s sampling of general education requirements, I was drawn toward the demonstrable truth found in the natural sciences. Eventually my love of the outdoors, mountaineering, and long discussions with my roommate about geologic time led to geophysics. I was privileged to have some truly inspiring teachers and mentors, including William Lipscomb in chemistry and Francis Birch in geophysics as an undergraduate and John Verhoogen, Allan Cox, and Mervyn Paterson as a doctoral student and postdoc. Given license to choose whatever interested me for my thesis, I hit on the ­­little-­studied problem of deciphering the ancient magnetic field intensity hidden in the paleomagnetism of rocks. I managed to make significant progress, but even more satisfying has been to witness the huge strides made since by many younger colleagues. After a formative postdoctoral year in Australia, I again met with great fortune by being offered a job at the new University of California campus in Santa Cruz. With it came the opportunity to help start a department of Earth sciences from scratch in an amazingly beautiful setting, in a culture that emphasized equally the instruction of undergraduate and graduate students, and with complete free rein to pursue my intellectual interests. I made some rewarding excursions into deformation experiments and phase changes in minerals, but once again the many varied aspects of paleomagnetism eventually captured most of my attention, with its combination of fieldwork, lab measurements, and theory. For my entire career, and now into retirement, I’ve been able to investigate the paleointensity, secular variation, excursions, and reversals of the geomagnetic field and tectonics and magnetostratigraphy in regions around the world including North America, Alaska, China, Siberia, and Papua New Guinea. What an incredible privilege it has been to be given the freedom to search for truth and beauty in the natural world, wherever my curiosity led me.

Beauty is truth, truth beauty—that is all

Ye know on earth, and all ye need to know.

Keats, 1819

—Robert Coe, Earth and Planetary Sciences Department, University of California, Santa Cruz