ETH Zentrum, Zurich, Switzerland
Albrecht W. Hofmann received the Harry H. Hess Medal at the 2001 Fall Meeting Honors Ceremony on 12 December in San Francisco, California. The medal is given for outstanding achievements in the research of the constitution and evolution of Earth and sister planets.
“Al Hofmann has been responsible for some of the major discoveries and current paradigms in mantle geochemistry stemming from the study of oceanic basalt. Therefore, it is particularly appropriate that he receive a medal named after Harry Hess, a pioneer in understanding the ocean floor and ocean islands. Al’s research also has provided inspiration to many younger scientists, myself included, by opening our minds to the creative uses of trace elements. The frustrating part is remembering any particular inspirational conversation with him, because he and Julie also have opened up their wine cellar on so many occasions. Therefore, I will focus on Al’s wonderful scientific career as opposed to my hazy recollections of my trips to Mainz.
“Al Hofmann’s earliest research was in diffusion. By the mid-1970s, so many brave but bad experiments had been attempted that the ability of experimentalists to provide reliable constraints on diffusivities in natural systems was being questioned. Then Al, along with others such as Bruce Watson, Stan Hart, and Al’s doctoral mentor, Bruno Giletti, started producing excellent data for silicates and silicate liquids. Al’s classic work provided the first constraints on the minimum length-scales of mantle isotopic heterogeneity. This was tough stuff. Al realized that he needed to slow down a bit, so in 1980, he left DTM and headed back to Germany, where he became director of the Geochemistry Division of the Max-Planck Institute for Chemistry in Mainz.
“Scientists who move back to Europe from the United States have a tendency to relax or disappear beneath editorships, committee work, or even organizing major conferences, all with the primary but clearly fruitless aim of competing with AGU. Al probably intended to be no exception. When he moved to Mainz and began collecting wines, he may well have sat with his feet up and contemplated an easy career ahead. He even might have said, ‘Let me get myself onto some big committees, and for the science we’ll just measure lots of ordinary basalt, the most common igneous material on Earth. We’ll get loads of new data, which everybody else will have to cite! Then my name as a memorable European geochemistry professor will be secure.’ You see, with his move to Mainz, Al was well placed to take advantage of excellent analytical support and, together with his colleagues Bill White and Klaus-Peter Jochum, was able to determine a range of critical trace elements. This foundation, if you like the very definition of what ‘normal’ basalt is like in terms of incompatible trace elements, has now formed the basis for everybody else’s research.
“However, Al is driven primarily by his interest in how the Earth ‘works.’ He could never be complacent and fail to use trace elements in creative ways. Instead he used basalt to sort out the VICE (very incompatible elements) and MICE (moderately incompatible elements) and came up with a sequence of increasing incompatibility that became the basis for modern mantle-normalized plots. More important, he discovered that certain element ratios that one expects to be highly variable because of subduction of altered crust and sediment are surprisingly uniform in normal basalt. Al was afforded no chance for relaxation but was doomed to a life at the forefront of scientific debate and discovery. He had stumbled upon something of deep significance. He even had the good taste not to name it another geochemical paradox. He showed that mantle trace elements carry the homogenized record of ancient crustal production and recycling and that isotopic heterogeneity has been largely superimposed upon this at a later time.
“Al’s insights into what must be causing this variability in isotopic compositions in the mantle are equally important. Together with Bill White, Al showed that the isotopic compositions of ocean island basalts largely reflected recycling. More than any others, these two individuals are credited with pulling together the idea that ocean island basalt is produced from melting deep-mantle plumes that originated as reheated deeply subducted ancient slabs. Like-minded contemporary visionaries, notably Clem Chase, came to similar conclusions.
“To sum up, Al Hofmann’s research on the study of the Earth’s interior has provided important foundations upon which the rest of us have come to rely. On behalf of all of your friends and colleagues around the world, Al I would like to say ‘many congratulations,’ and also ‘many thanks’ for your contributions, support, and inspiration, not to mention the wine cellar.”
—ALEX N. HALLIDAY, ETH Zentrum, Zurich, Switzerland
“Thank you, Alex, for your kind words of praise, and thank you, Hess Medal Committee, for making such a fortunate choice. Fortunate for me, anyway. I want to tell you a little personal story, which may explain why the Harry Hess Medal is more special to me than any other recognition I could possibly ever receive.
“Almost exactly 40 years ago, while nominally studying geology at the University of Freiburg, Germany, but actually spending most of my time at the local pubs, I decided that, in order to improve my personal work ethic, I needed to go to graduate school in the United States.
“So I wrote a letter to my older brother, Fritz, who was a postdoc at the Plasma Physics Lab in Princeton. I asked him to go to the geology department and find out which American graduate schools might have suitable departments where I might send my application.
“Fritz went and by chance encountered the department chairman, who was none other than Harry Hess. Hess explained to Fritz that his kid brother would have a hard time being accepted by the traditional ‘good’ schools because of a serious lack of credentials. However, there were two schools with brand-new graduate programs in geology, and not too many people knew about them, so chances of acceptance to these schools would be significantly enhanced.
“The two schools were Brown University and Scripps. I applied to both of them, in addition to a more traditional list of the usual suspects like Harvard, Princeton, Yale, etc. I was promptly rejected by all of them, except-you guessed it-Brown and Scripps. The letter from Brown arrived a few days before the Scripps letter. I accepted the same day. “So you see, I literally owe my career almost entirely to Harry Hess’s excellent advice to me via my brother, and I can assure you that without Harry Hess, whom I never met in person, I would not be standing here in a Penguin suit.
“There is, yet, just a little more to the story: I enrolled at Brown in September 1962, went to New York City for the Annual Meeting of the Geological Society of America 2 months later, and listened raptly to a presidential lecture entitled ‘An Essay in Geopoetry,’ delivered by none other than Harry Hess. In retrospect, I think I witnessed the birth of the modern theory of the Earth.
“Unlike the smart, young, and eager faculty at Brown, who were working hard at turning traditional geology into REAL science, and therefore didn’t have many good things to say about this lecture, and perhaps because I was not weighed down by a lot of previous knowledge, but had indeed heard of Alfred Wegener’s theories, I found this geopoetry all quite interesting and reasonable. I think it also helped me to recognize and accept speculation as an important tool of science.
“Fortunately for me, my luck did not stop with the serendipitous Harry Hess effect. I came to Brown hating chemistry, as a result of some particularly bad high school grades. But somehow, I ended up in the gentle fangs of my subsequent long-term mentor and friend, Bruno Giletti, who assured me that isotope geochemistry wasn’t really too much like real chemistry, so that it would be safe to do a master’s thesis on the subject. Eventually, I became his first Ph.D. student. It was Bruno who turned me into a scientist, by teaching me about isotopes, thermodynamics, the dangers of cheap liquor and bad food, and many other important things in life.
“Still, my luck did not stop even then: I was accepted by the Carnegie Institution of Washington and spent 10 of the most rewarding years of my life in the company of people like Stan Hart, Tom Krogh, Nobu Shimizu, and my first postdoc, Mordechai Magaritz, who is, unfortunately no longer with us.
“Ten years went by, and then Max Planck made an offer I couldn’t refuse. Thus, for the past 21 years, I have had the privilege to work with a large group of outstanding scientists and students from many countries, and with many outstanding technicians, administrators, and secretaries. I hope they will forgive me, and I am sure you will forgive me, if I don’t name them individually. I am truly grateful to all of them, but in retrospect, I would have given a lot to have had the chance to meet and thank Harry Hess in person.
“Thank you all very much for listening to my story.”
—ALBRECHT W. HOFMANN, Max Planck Institute for Chemistry, Mainz, Germany