Gold Medal

Creek for his birthday party. "You ought to come back for it," she said. I said I would try. Then on Sunday last, when I was getting ready to drive to Cincinnati to catch my plane back to California, I walked out to the little convenience store near my sister's house to buy a Lexington Herald-Leader, and on the front page, left column, I saw "James Still, Appalachian writer, dies." Yesterday I read to my classes Jim's mountain version of "Jack and the Beanstalk" and that wonderful little story "Mrs. Razor," about the six-year-old girl with an imaginary triflin' husband; and then I read them Jim's poem "Heritage," reciting those last two lines—And one with death rising to bloom again, I cannot go. Being of these hills I cannot pass beyond—with a bittersweet new resonance. As my flight took off for Los Angeles, I put my hand on the window and looked to the hills south. With a smile of reconciliation, I saw the hand of my grandfather, my father, Jim Still all those men I have watched age and pass from me, and I knew that although I seemed to leave, "Being of these hills" nor can I pass beyond.

Institution of Oceanography, University of California is proposed for the Price Medal for her fundamental contributions to the robust statistical analysis and modelling of palaeomagnetic and geomagnetic data. She took her BSc from the University of Western Australia in 1979, an MSc from the Australian National University in 1982 and then moved to the USA, where she obtained her PhD from Scripps Institution of Oceanography in 1987. After a short spell as a postdoctoral research assistant at Scripps, she joined their faculty in 1990, where she is now Associate Professor.
Geomagnetists frequently model the geomagnetic and palaeomagnetic fields, and their secular (time) variation, by a series of spherical harmonic, or Gauss, coefficients. We have a good description of the current field through such models, and Cathy used its spatial power spectrum to develop statistical model both for the secular variation over the past 5 million years, and reversals. She found that the palaeo-magnetic secular variation can be modelled by random samples of these coefficients from a prescribed probability distribution. This was a novel way of viewing field variations, and has been widely used, and subsequently refined, by others studying the increasing quantity of palaeomagnetic measurements.
When there were fewer data available from reversals, simple zonal or standing field models reflected them adequately. More detailed transitional records demanded a more complex model, but Cathy was able to produce a model described by just three parameters that describes the statistical behaviour of the field during reversals. As part of these studies, she also produced better methods (than simple least squares) for estimating parameters in the presence of non-Gaussian noise, involving "bootstrap" methods to provide meaningful confidence limits on their values. As an example, she separated geomagnetic storms and other phenomena from geomagnetic observatory records, but they have many other applications.
More recently, she has turned her attention to recent and historical observations of the geomagnetic field. She developed a new technique for modelling the field at the core-mantle boundary (the top of the source region), again with a built-in-smoothness criterion to find the least complicated model, to reduce the chance of artefacts and errors in the data being interpreted. This has cast a new light on the continuing controversy over the extent to which Ohmic diffusion is important on the decade timescalewith her method, it is relatively simple to produce models consistent with no diffusion, characterized by the same measures (fit to the data, smoothness) as previous models which do show diffusion. She, contemporaneously with but independent of David Gubbins, also produced maps of the averaged palaeomagnetic field at the core-mantle boundary using the same techniques as applied to recent and historical data, enabling a valid comparison to be made between our current "snapshots" of the field and its long-term behaviour. From this, we are gaining new insights into which features of the field are persistent, and whether there is a statistically significant difference between the field morphology in its normal and reversed states.
Cathy's work has had, and will continue to have, a profound influence on geomagnetism and palaeomagnetism. Her palaeomagnetic analysis techniques, developed from a sound statistical basis, are immensely practical and provide meaningful uncertainty estimates. Her geomagnetic and palaeomagnetic field analysis methods allow rigorous tests of hypotheses of the dynamical state of the core and its history. She has shown how to analyse data robustly, how to pose meaningful questions of them, and how to answer those questions. For these contributions, she is awarded the Price Medal.

Prof. Catherine G Constable: Price Medal Winner 1997
K enneth Creer has recently retired as Professor of Geophysics in the Department of Geology and Geophysics, University of Edinburgh. He is distinguished for his research in palaeomagnetism and rock magnetism. Creer made some of the first palaeomagnetic surveys: of the Palaeozoic in Great Britain and the Phanerozoic of South America. He determined, with Irving and Runcorn, the first polar wandering curve (for Great Britain) and was the first to make reconstructions of the continents based on palaeomagnetism alone.
In his early work he was interested in the mechanism by which rocks become magnetized, and he contributed to the development of laboratory methods of the demagnetization of secondary components. Whilst professor of magnetism in the University of Newcastle upon Tyne he built up a laboratory on the physics of the iron oxide minerals, demonstrating the impor-tant role played by superparamagnetism in the magnetic properties of rocks. He showed how the characteristics of the geomagnetic secular variation could be determined from the scatter of the palaeomagnetic directions in rocks.
More recently he has extended such studies in an important way by applying the Mackereth corer to the study of uncompacted sediments (e.g. in lakes). This external development has spread to many laboratories throughout the world. The records are providing critical tests of various models of the core dynamo field. Creer's work has always been characterized by considerable skill and by keen insight into the relationship between geophysics, physics and geology.
Creer has always had close relations with scientists in other European countries. He spent a considerable time in Neel's laboratory in Grenoble, and through his work there he contributed considerable to our understanding of the physics of rock magnetism.
Many palaeomagnetists, now leaders in this field in their own countries, owe their initial training to working with Creer in Newcastle or Edinburgh, and the successful development of palaeomagnetism in south America is entirely due to Creer's initiative.
Although retired, Creer continues to be active scientifically. He recently spent an academic year as a Visiting Professor at the University of Wisconsin, Madison, and will continue collaborating on links forged there from Edinburgh.
He was, for many years, the Managing Editor of Geophys. J. R. astr. Soc., and oversaw the successful merger with European journals to form Geophys. J. Int. He has recently handed a vibrant Geophys. J. Int. over to a new Managing Editor.
Creer was one of the instigators of, and hosted the first, UK Geophysical Assembly in 1977. This is an important platform for young geophysicists in all disciplines, whom he has always supported, to "cut their teeth" on conference presentations, and is now a well established annual event. He also actively encourages European collaboration. He was President of the European Geophysical Society 1991-93, and arranged for some overlap between the UK Geophysical Assembly and the European Geophysical Society meeting, when they were both held in Edinburgh in 1992.
Kenneth Creer is awarded the Gold Medal of the Society by virtue of his great contribution to geomagnetism and geophysics generally.