Glaciology has now reached a stage when mere observation in the field is no longer an adequate method of attack for the problems which are still unsolved. Experimental research on the fundamental physical and mechanical properties of ice is urgently required before a quantitative theory of glacier flow, based upon modern concepts of plasticity in crystalline solids, can be formulated. For testing such theories in the field, novel methods of research will be needed for measuring flow rates and stresses in the interior of glaciers at considerable depths.
It is clear that the development of research on lines such as these will only be possible with the co-operation of experts in several fields. With this purpose in view a Glacier Physics Committee has been formed on the initiative of Dr. M. F. Perutz and under the chairmanship of Mr. G. Seligman. The following have agreed to serve on it:
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Dr. F. P. Bowden (Friction of solids).
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Dr. E. C. Bullard, F.R.S. (Geophysics).
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Mr. Vaughan Lewis (Geomorphology).
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Professor A. Austin Miller (Geology, Geography) representing the Royal Geographical Society.
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Dr. E. Orowan, F.R.S. (Plasticity).
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Dr. M. F. Perutz (Crystallography), Honorary Secretary.
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Sir Geoffrey Taylor, F.R.S. (Applied mechanics).
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Mr. J. M. Wordie (Polar exploration, glaciology).
The opinion was held that the Committee should be composed mainly of residents in Cambridge in order to facilitate formal and informal meetings. This arrangement has proved satisfactory and since the first meeting much useful preliminary work has been accomplished.
The first meeting to decide on methods and on general lines of procedure was held on November 8, 1946.
The discussion centred first on suitable methods for determining the creep properties of ice and of measuring flow rates and stresses in the interior of glaciers. Sir Geoffrey Taylor and Dr. Orowan expressed the opinion that the hydrodynamic treatment of glaciers as a flowing mass of constant viscosity, which had been customary in the past, was an inadequate approximation and was not in accord with modern knowledge of the behaviour of polycrystalline masses undergoing plastic deformation. They considered it essential to measure the yield stress and the creep rates of ice under conditions similar to those prevailing in a glacier. Dr. Perutz thought that such research should be closely linked with microscopic studies of crystal growth and re-orientation under strain. The Committee recommended that researches on these lines should be undertaken at the Cavendish Laboratory under the general direction of Dr. Orowan and Dr. Perutz, provided sanction to carry out this work could be obtained.
In order to measure flow rates and stresses in the interior of glaciers it will be necessary to devise an efficient method of drilling holes in glaciers. Dr. Bullard suggested various techniques which might be tried. Dr. Orowan mentioned new types of strain gauges which might be used for measuring the stresses at the bottom of bore-holes. It was suggested that flow rates in the interior of glaciers might be measured with the help of timed detonators which could be placed in bore-holes at determined positions in the glacier. Explosion could take place some weeks or months later and the position of the detonators at the time of explosion could be determined seismographically. The Committee recommended that these methods should be developed under the general direction of Dr. Bullard.
The Committee was anxious that glaciological research in the Polar regions should be revived and suggested that this might conveniently be done in Connection with the Falkland Islands Dependencies Survey, if facilities to carry this out were granted. It was feit that only a long-term scheme would yield scientific results of any value, because it would be necessary, before any serious research could be begun, to make a preliminary survey of the problems that needed investigation and of the localities where such investigations could conveniently be carried out. The Committee recommended that the Secretary should approach the Colonial Office to see if it were possible to secure the appointment of a glaciologist within the framework of the Falkland Islands Dependencies Survey for a period of five years. It was thought that there would be no very great difficulty in finding a young Student willing to train for this work.
In order to guide the Committee in formulating a detailed programme and in devising suitable methods of research, Dr. Perutz has written a report summarizing the present state of the problems of Glacier Physics. This summary is published below.
