David Gubbins was awarded the Fleming Medal at the AGU Fall Meeting Honors Ceremony, which was held on 15 December 2004, in San Francisco, California. The medal recognizes original research and technical leadership in geomagnetism, atmospheric electricity, aeronomy, space physics, and related sciences.
David Gubbins is one of the most complete geomagneticians possible. His research has cut across the traditional disciplines in geomagnetism, taking him from theoretical magnetohydrodynamics and thermodynamics to observational geomagnetism, palaeomagnetism, and applied crustal magnetism. This breadth has made Dave unique in the subject. That Dave has worked so widely is entirely characteristic of him: His instinct is to follow a problem wherever it leads if he thinks it will bear fruit, and he has no regard for boundaries.
Dave began his research working on kinematic dynamos with Teddy Bullard, and was one of the first to find convincing examples of working dynamos. A second fundamental contribution from Dave’s early career was made in a series of papers in the late 1970s, in which Dave and collaborators Jack Jacobs and Guy Masters began a careful analysis of the thermodynamic equations governing core convection and magnetic field generation. Although this topic has been revisited since, the conclusions stand essentially unaltered today.
Dave combines rigorous mathematical and computational analysis with remarkable physical insight, and is not averse to speculation. For example, in an amazingly prescient paper in the Bullard volume of JGR in 1981, Dave predicted that the inner core was likely to rotate in response to electromagnetic torques acting on it. Numerical dynamos exhibit this effect, and this spawned a whole new (controversial) area, leading seismologists to scrutinize their records for evidence of the effect.
Dave is almost certainly best known for his work on mapping of the field at the core-mantle boundary. He was the first to realize that this is really an inverse problem, addressed in a seminal paper with Kathy Whaler in 1981.
Dave realized the potential benefits of pushing the techniques back into the past; with Ph.D. students beginning with Jeremy Bloxham, Dave created maps of the magnetic field back to 1650.
The fruits of this labor were enormous. The maps revealed an intriguing near-symmetry in the field, and the location of high-latitude flux patches was tantalizingly suggestive of the influence of the inner core. And the longevity of the high-latitude flux patches led Dave to contemplate thermal or topographic coupling to the lower mantle, an effect demonstrated in a series of papers from his long-standing collaboration with Keke Zhang.
I think our picture of the core magnetic field has never been the same since. Dave has been the author of two books and has been an extremely effective mentor for Ph.D. students; 10 of the 17 theses Dave has advised have been in geomagnetism (his other career being a seismologist!).
A tireless servant to the community, Dave has never shied from controversy; for example, his constant needling of palaeomagneticians has led to a much improved discourse between them and the rest of the geomagnetic community. He has served as SEDI chairman, embracing all disciplines relevant to the real focus of his research, the core. It is with pleasure that I present to you my colleague and mentor David Gubbins as the recipient of the 2004 John Adam Fleming Medal.
—ANDREW JACKSON, University of Leeds, U.K.
It is a great honor to accept this 2004 John Adam Fleming Medal from the AGU, and a pleasure to receive such a flattering citation from my colleague and friend Andrew Jackson. The Fleming Medal is given for all forms of geomagnetism, and the list of recipients includes the most brilliant scientists in the field. Two, George Backus and Jack Jacobs, have been very influential in my own scientific development and career.
I have had a lucky career in science. I was lucky to belong to a generation that could attend university in Britain without vast expense to the family, and to have the example of an older brother who was already enjoying a successful academic career. I was lucky that Cambridge took me on despite the advice of my headmaster, and lucky to eventually find myself in Teddy Bullard’s Department of Geodesy and Geophysics in Cambridge, then one of the great crossroads for geophysicists as well a hive of activity itself in the immediate aftermath of the plate tectonic revolution.
It was pure luck to start a Ph.D. in dynamo theory at the time of the smaller, but no less significant, revolution in dynamo theory that occurred in the early 1970s when the work that had been going on for a decade behind the iron curtain by people like Stanislav Braginsky, another Fleming medalist, and Fritz Krause, reached the west; and I was lucky enough to have Keith Moffatt on hand to explain it to me.
My postdoctoral work was in the United States, as it was for many scientists of my generation. In 3 years, I learned the organization and generosity of American science, attained what was then called the ‘BtA’ degree, and returned, with trepidation and some reluctance, to Cambridge and a salary cut of a factor of 5. There my career might have faltered were it not for Jack Jacobs, another Fleming medalist, who had himself just taken a salary cut of a factor of 7 to return from Canada.
Cambridge under Jack continued to be a wonderful place to do science. For me, the years were marked by what now seems like an endless stream of brilliant students, many of whom have stayed in the subject: Guy Masters, Kathy Whaler, Carl Spencer, Colin Thomson, Jeremy Bloxham, Andrew Jackson. Later in Leeds I was joined by Ken Hutcheson, Gideon Smith, Graeme Sarson, Steve Gibbons, and Nick Teanby; the scientific achievements listed in the citation owe more to them than to me.
It is disingenuous to take pride in one’s students achievements, but I cannot help but be proud of having supervised the first woman to be appointed to a chair of geophysics in the U.K.—only the second in the whole of Earth sciences—Kathryn Whaler.
At Leeds, I have been lucky in attracting some brilliant geophysicists to join the department; the U.K. has never had a more stimulating Earth science community. I must make special mention of my scientific collaboration with Keke Zhang. Working with Keke is like getting off your bike and getting a ride in a fast car: Ideas are formulated, tested, replaced, without any worries about a problem extending into months or years. Our collaboration continues today, and will continue as long as I am able to keep up with him.
Geomagnetism is a small but essential part of geophysics. The GP section of AGU is one of the smallest, but it has contributed to many major discoveries, not least the use of reversals in dating plate motions. It is a difficult subject, but the surprises keep coming and I shall continue to enjoy the discoveries to come.
—DAVID GUBBINS, University of Leeds, U.K.