Quentin Williams

2000 James B. Macelwane Medal Winner

University of California Santa Cruz

Quentin C. Williams was awarded the James B. Macelwane Medal at the AGU Fall Meeting Honors Ceremony, which was held on December 17, 2000 in San Francisco, California. The medal recognizes significant contributions to the geophysical sciences by a young scientist of outstanding ability.


“It is a great pleasure to celebrate Quentin Williams’ selection as one of this year’s recipients of the Macelwane Medal, in recognition of his remarkable achievements and tremendous potential for his contributions to our understanding of the properties of materials under extremes of temperature and pressure. Quentin is known to colleagues and students alike as a hyperactive intellect, with a phenomenal repository of scientific information of stunning breadth as well as endless obscure trivia about history and academia. His academic career launched when he completed his A.B. in chemistry at Princeton in 1983 at the age of 19. He changed coasts to pursue his graduate work at Berkeley, where he worked with Raymond Jeanloz and Ian Carmichael on a large suite of projects. His Ph.D. in geology was completed by 1988. Quentin’s thesis work had already elicited international interest when he then became a lecturer and assistant research geophysicist at U.C. Santa Cruz. He moved onto the faculty at UCSC in 1991 and is now a full professor in the Earth sciences department. In 1993 he was awarded a Presidential Faculty Fellowship, which allowed him to match wits with President Clinton in the Rose Garden. This year, he was also recognized with the Mineralogical Society of America Award.

“Quentin’s creative and prolific research contributions on the behavior of Earth and planetary materials under a vast range of physical conditions have had broad interdisciplinary impact on a variety of forefront topics in mineral physics, seismology, geochemistry, petrology, and structural geology. He combines theoretical expertise with analytic tools such as micro-Raman and infrared spectroscopy, X ray diffraction, and laser-heated diamond cells to conduct ground-breaking experiments on material properties. He has contributed extensively to our knowledge of the thermal and chemical state of the Earth’s core, with the pioneering work in his thesis stimulating extensive investigations throughout the past decade. The UCSC laboratory that he has established for vibrational spectroscopy has targeted the properties of structural transformations in melts at high pressure, again providing impetus for extensive theoretical modeling efforts by many in the mineral physics community. Quentin has also pursued in recent years investigations of hydrous phases and possible reservoirs of water and other volatiles in the mantle.

“A true distinction of Quentin’s research has been his interdisciplinary forays. He has collaborated on developing new models of basalt petrogenesis, drawing on uranium series disequilibria; he has worked on deformation indicators provided by mafic enclaves in Sierra Nevada granites; he has worked on deep focus earthquake ruptures and meta-stable olivine wedges in subducting slabs; and he has worked extensively on possible partial-melting of the base of the mantle as an explanation for the seismically observed ultra-low velocity zone. In working with many colleagues and a broad range of observations from geochemistry, structural geology, seismology, and geodynamics, Quentin has demonstrated remarkable breadth of interest and expertise. He brings this breadth to the classroom, constantly challenging students to think outside narrow disciplinary boxes, and in this manner is instilling an interdisciplinary perspective into all of his students and advisees.

“Clearly, much more is yet to come, and I have no doubt that Quentin will continue to excite and dazzle us with his contributions. For the moment, though, it is a timely pleasure to take a breath and simply enjoy the many ideas and accomplishments that Quentin has laid before us.”

—THORNE LAY, University of California Santa Cruz


“Thank you President McNutt and Thorne for those kind words. I am enormously grateful for this award. My notification of it arrived some months ago in a Federal Express envelope from AGU. Given its source, I assumed that the contents had something to do with a committee, or worse yet, contained something to review. Being a horrible procrastinator, I let the envelope languish on my desk for an inordinately large number of days. When I finally opened it, I was pretty shocked, and as evidence that there are some disadvantages to starting early in science, virtually everyone who heard about the award said something along the lines of, ‘I thought you were too old for the Macelwane Medal.’ In fact, one of my own colleagues, Rob Coe, said to me, ‘How can you still get this award? You’ve been around here forever!’ And indeed, I’ve spent the last 12 years at the University of California, Santa Cruz, initially as a researcher in the Institute of Tectonics and then as a faculty member. I was hired at UCSC along with my wife and closest collaborator, Elise Knittle, without whom I surely would not be here today. My stock-in-trade is mineral physics, the study of the properties of Earth materials, and my colleagues at UCSC have provided an extraordinarily exciting, interactive, and intellectually stimulating environment that has allowed me to explore the many linkages between my own discipline and topics as diverse as seismology, geochemistry, structural geology, and archaeology. Indeed, my early interest in high-pressure silicate melt structure, started during my Ph.D. work with Raymond Jeanloz at U.C.-Berkeley, has evolved into a common theme dealing with the critical role of partial melting in Earth processes. From seismically anomalous, likely partially molten zones at Earth’s core-mantle boundary that may control the formation of mantle plumes, to the melting processes that take place beneath mid-ocean ridges, the structure and properties of melts and partially molten zones permeate much of my research. My interest in these crucial problems of planetary differentiation builds on my early interactions with Ian Carmichael.

“Much of my laboratory work has been spectroscopic in nature: probing the bonding properties of melts and minerals at the extreme pressures of Earth’s interior. Strangely enough, I learned an alarmingly large portion of the skills that I use in this work as an undergraduate in chemistry at Princeton University.

“My students at U.C.-Santa Cruz have been indispensable in these pursuits, and this award is certainly as much a recognition of their efforts as my own. My student collaborators Dan Farber, Craig Lundstrom, Claire Closmann, Jessica Faust, Eli Morris, Phillip Cervantes, Henry Scott, and Murray Eiland have each taken me in new and unforeseen research directions. Throughout, deep Earth and high-pressure problems have proved, and continue to prove, to be fertile ground: the incredible unexplored frontier and intellectual challenges represented by studies of the deep Earth, a region difficult to interrogate and harder to simulate, can’t help but produce an abiding fascination.

“In closing, I have to completely gratuitously mention my 4 kids: Byron, Alanna, Lynette, and Benjamin. I mention them not because they had anything substantive to do with this award, but only because they like to see their names in print almost as much as I like to see mine. Thank you again for this award!”

—QUENTIN C. WILLIAMS, University of California Santa Cruz