Canadian Geophysical Union Scientific Meeting

Following a very successful joint meeting with the AGU In Montreal in 1993, the Canadian Geophysical Union returned to its regular venue at Banff, Alberta, in 1993. One hundred and forty-two papers were presented in 16 sessions.

Wilson Medal to A. E. Beck

The Wilson medal is awarded annually by the CGU in recognition of outstanding contributions to geophysics in Canada. This year the recipient is Alan Beck of the University of Western Ontario. Alan Beck arrived in Canada in 1957 as a National Research Council Fellow in physics. The following year he joined the then new Geophysics department at the University of Western Ontario as an Assistant Professor. By 1963 he was Head of the Department, and has remained so until the present.

His research interests have been mainly in terrestrial heat flow and the thermal state of the Earth, and he has published extensively, 84 scientific papers to date. His “The Physical Principles of Exploration Methods” is now in its second edition. He has served on far too many national and international scientific organizations to list here, but some of the more noteworthy are: President of the International Heat Flow Commission (1983-1987), Chairman of the Natural Sciences and Engineering Research Council Earth Sciences Grants Selection Committee (1983-1984), member of the Executive Committee of the International Association of Seismology and Physics of the Earth’s Interior, Chairman Canadian Council of Earth Science Departments, member of the IUGG working group for the International Geological-Biological year (1987).

In his nominating address, Lalu Mansinha described Beck’s unflagging defence of academic freedom and collegiality, and told of how his tireless efforts on behalf of his colleagues in the Geophysics Department spared them the unending round of committee meetings that consume so much of research and class preparation time.

The Canadian Geophysical Union owes a special thanks to Alan Beck, as it was during his tenure as President of the Earth Physics Branch of the Canadian Association of Physicists, that the groundwork for the creation of the Canadian Geophysical Union was laid.

The CGU was especially saddened to hear of the death of John Tuzo Wilson, only a few months before the meeting. Wilson himself was the first recipient of the medal which bares his name, and was occasionally able to be present at ceremonies honoring other recipients. He will be missed by all earth scientists.

Research Hydrologists Join CGU

Research hydrologists in Canada recently voted to form a section of the Canadian Geophysical Union. They bring over a hundred new members to our ranks, and we were delighted to welcome them to their first CGU meeting. Three separate sessions dealt with hydrological problems ranging from global water cycles, to problems of snowmelt infiltration and run-off in prairie agricultural regions. Milne Dicke, of the National Hydrological Research Institute, will serve as the first section head.

Student Paper Competition

The CGU views the participation of students in scientific meetings as an important part of their education, and encourages students to present their work by offering awards for excellent presentations. In addition to the CGU’s own best student paper award, Chevron Canada makes an award for the best student paper in seismology and Shell Canada for the best poster presentation by a student.

W. Sean Guest (with J. M. Kendall) has continued a Queen’s University record of success by winning the Chevron Canada award for best paper in seismology. “Modeling Seismic Waveforms in 3-D Inhomogeneous Anisotropic Media: Application of Maslov Asymptotic Theory” addressed the problem of the breakdown of zero-order ray theory for signals such as caustics, grazing rays and head waves. Maslov asymptotic theory handles these exceptional cases by including waveform contributions from signals neighbouring the geometrical arrival in the zero-order theory. The method was illustrated by a synthetic crosshole experiment in which the boreholes were located in an anisotropic salt body. Maslov and zero-order theory were in agreement for some phases, but only the Maslov theory handled amplitudes near the cusps of a triplication correctly, as well as revealing Airy diffractions.

Kevin Shook (with D. M. Gray) from the University of Saskatchewan, won the CGU award for a paper on the “Geometry of Prairie Snowcovers”. It was shown that on small scale transects, prairie snowcover is fractal, and that by extension, the water equivalent of the snow load is also fractal. The ablation of fractal snowcovers was shown to produce soil and snow patches with geometry similar to observed ablated snowcovers. Perimeter-area and size frequency relationships obeyed power laws.

Nong Wu (with J. R. Booker and J. T. Smith) from the University of Washington won the Shell Canada poster paper competition for the “Constrained Rapid Relaxation Inversion of Magnetotelluric Data”. This new, multi-dimensional, technique allows the incorporation into the inversion of discontinuous boundaries and a-priori information on conductivities, as well as different measures of solution roughness in specified local areas. Real and synthetic data were used to illustrate the method.