William J. Jenkins

2010 Maurice Ewing Medal Winner

Woods Hole Oceanographic Institution, Woods Hole, Mass.

William J. Jenkins was awarded the 2010 Maurice Ewing Medal at the AGU Fall Meeting Honors Ceremony, held on 15 December 2010 in San Francisco, Calif. The medal is for “significant original contributions to the scientific understanding of the processes in the ocean; for the advancement of oceanographic engineering, technology, and instrumentation; and for outstanding service to the marine sciences.”


William (Bill) Jenkins’s research record is remarkable for its exceptional quality, depth, and diversity, with major scientific findings spanning solid Earth geochemistry and physical, chemical, and biological oceanography. Few scientists can claim such substantial impact and recognition across so many different aspects of geoscience. He is the rare scientist who designs and builds new instruments, performs superb laboratory and field measurements, and generates novel data analysis and theoretical advances.

Bill is perhaps best known for pioneering the ocean tritium-3He dating method. In the early 1970s he developed mass spectrometric methods for measuring seawater tritium and its decay product 3He and was the first to envision how coupled tritium-3He measurements constrain the ventilation age for water parcels. He has made extensive use of tritium-3He to trace pathways and quantify rates of ocean circulation, combining in an elegant fashion transient tracer data, which inherently integrate over interannual to decadal time scales, with quantitative models and more traditional ocean physical velocity estimates.

In those early days it was not possible to purchase a 3He/4He ratio mass spectrometer; they had to be “homemade.” Bill has continued to push the boundaries for 3He mass spectrometry and sample collection, freely sharing new techniques now used by many other laboratories around the world.

Using tritium-3He ages, Bill introduced the essential element of time to quantify the evolution of upper ocean and subsurface biogeochemical fields. His work on oxygen and nutrient dynamics in the subtropical North Atlantic was paradigm shifting, overturning traditional wisdom based on 14C incubation studies that indicated low biological productivity and carbon export flux in oligotrophic oceans. He went on to develop a series of independent geochemical measures, all of which support elevated subtropical biological productivity.

Bill also has made fundamental contributions to solid Earth geochemistry. He made the first measurements of primordial 3He in mid-ocean ridge hydrothermal vent fluids. Using the relationship between heat and 3He, he made the first direct calculations of the global 3He outgassing rate from the ocean floor, an approach used widely to calculate geochemical fluxes from the ocean crust. Bill also pioneered the measurement of helium in oceanic basalts as a tracer of primordial gases in the mantle.

Bill is an excellent mentor for students and younger colleagues and a leader of the scientific community. He has played a significant leadership role in all of the major ocean chemistry and hydrographic programs over the past 30 years, including Geochemical Ocean Sections Study (-GEOSECS), Transient Tracers in the Ocean (TOS), South Atlantic Ventilation Experiment (SAVE), Joint Global Ocean Flux Study (JGOFS), World Ocean Circulation Experiment (WOCE), Surface Ocean Lower Atmosphere Study (­SOLAS), Climate Variability and Predictability (-CLIVAR/CO2), and -GEOTRACES, and he currently is director of the National Ocean Sciences Accelerator Mass Spectrometry Facility. In addition to his brilliance as a scientist, he is well known for his openness and (sometimes offbeat) sense of humor, all of which make him a great colleague.

Bill’s scientific accomplishments have been recognized through numerous awards including the Rosenstiel Award, Bigelow Medal, Huntsman Medal, the AGU Sverdrup Lecture, and his election as a Fellow of AGU, the Geochemical Society, and the European Association of Geochemistry. The Ewing Medal is a fitting tribute to his wide–ranging intellectual contributions and his meticulous measurement standards as an ocean chemist and physicist.

—SCOTT C. DONEY and MARK KURZ, Woods Hole Oceanographic Institution, Woods Hole, Mass.


I want to thank Scott Doney and Mark Kurz for their kind and generous comments and the award committee for accepting the nomination. I am deeply honored to receive the Maurice Ewing Medal. Many of us are motivated by the belief that what we do has some intrinsic value to society, but receiving recognition from our peers is an unanticipated and unparalleled joy, for it is our peers who understand the significance and challenges of our endeavors. At the same time, I am humbled when I look at the list of previous recipients. I am also grateful to the many people who have contributed so much; science does not happen in a vacuum. Many ideas have grown from spirited discussions with many of my colleagues. There are far too many to mention here, but you know who you are. I thank you for sharing ideas and inspiring me. Also, because some science does happen in a vacuum, I want to thank Dempsey Lott, who has worked with me for over 3 decades making things in the lab work much better than I possibly could. I owe him a lot. I especially would like to thank my former students for letting me play a role in their careers; working with them has been both a joy and a privilege. Finally, I owe it all to Susan, who keeps my rather large feet on the ground, even though my head is mostly in the clouds.

—WILLIAM J. JENKINS, Woods Hole Oceanographic Institution, Woods Hole, Mass.