Observations have been made in one of several deep holes drilled in Salmon Glacier in the course of mining development. Surveys, particularly of the displacement of a 481.5 m. length of pipe in this hole over a 94 day period, show movement diminishing downward from a maximum value of 0.225 m./day at the surface, through a slightly lower value at mid depth to 45 per cent of this value at the bottom of the pipe. By extrapolation movement on the glacier floor, 490 m. below the surface, is believed to be about 44 per cent of the surface rate. The data closely approximate Nye’s (1952) theoretical formula for laminar flow:

in which u0=78 m./yr., α=2°00′, n=2.8 and K=1.25×10−4. Maximum shear stress at the glacier floor is calculated to be about 1.42 bars.

Both long and short-term snow ablation measurements usually contain errors when made with a simple ablation stake. Ablations measured over long periods for glacier regimen studies are subject to a settlement error in even dense snow, corrections for which may be made by simultaneous measurements with stakes of different lengths. For observation periods in the order of twenty-four hours or less, both mass loss and ice melt are often poorly represented by the simple product of mean bulk density and change in surface level. These quantities may be measured directly by successive determinations of bulk density and ice density profiles in the surface snow layer. Under certain favorable conditions, they may also be derived by observing directly the total and ice mass changes in a sampled area of the snow surface.

A series of deformation measurements have been selected for preliminary studies on the plasticity of Greenland glacier ice. The measurements to be reported on were obtained in the Red Rock and TUTO tunnels in north-west Greenland. Both tunnels were excavated during the summer of 1955 with some additional work done during the summer of 1956. Deformation measurements made up to the end of the 1956 summer season, therefore, are of limited reliability, but certain trends appearing in these data seem worth reporting. The topics discussed are (1) the shearing of an initially vertical peg system at Red Rock, (2) the deformation of core holes at TUTO, and (3) tunnel closure at both sites. These data are analysed on the basis of laminar flow of the Nye type and certain conclusions are derived.

Glaciological studies during the Sheffield University Expeditions to Kilimanjaro in 1953 and 1957 included a survey of the glaciers and a close examination of the Penck Glacier and the stagnant remnants of the ice cap on the summit. The Penck Glacier has done little downcutting although it rests on friable rock. The glaciers and summit remnants are rapidly retreating, the Penck Glacier having retreated 3 m. in 3 months in 1957, and nearly 300 m. since 1912. The main accumulation zone appears to be at about 4,500–5,000 m. with a local “low level” firn line and an upper firn line above the top of the mountain. Maps of the glaciers, their recent fluctuations and moraines are being prepared. The glaciological and meteorological observations in 1957 form part of the I.G.Y. programme for East Africa.

The glaciological work of the I.G.Y. Mt. Kenya Expedition, 1957–58, is described and some results are given.

The stages of retreat of the Mt. Kenya glaciers from their former limits are considered with reference to moraine evidence and existing records. A chronology is suggested for fluctuations during the last century.

Mapping of the present glaciers has been carried out. The changes undergone by the Lewis Glacier since a previous survey in 1934 are considered. The surface movement of the Lewis Glacier has been measured and its economy examined in relation to the meteorological and climatic environment.

The distribution of velocity along a vertical line in Greenland is calculated. Almost all the relative shear motion is concentrated at and very near to the bottom, and this result is thought to apply generally in Greenland and Antarctica. It is due to the relatively high temperature of the lowest layers and the strong dependence of creep rate on temperature. The outward velocity being thus almost constant with depth, it is assumed proportional to the mth power of the shear stress on the bed; the results previously obtained by the approximation of perfect plasticity then correspond to m→∞. Steady-state solutions for finite m are derived, and non-steady states are discussed by use of Weertman’s perturbation method. The steady-state height of an ice sheet is found to be very insensitive to the rate of accumulation. Surface waves in Antarctica are attributed to mountains buried beneath the ice, and it is shown how the height and form of a buried mountain ridge may be calculated from the associated surface disturbance.

The application of a law of sliding to glaciers leads to an expression for the longitudinal strain-rate, hitherto an undetermined parameter.

A new method for measuring ice tunnel deformation and closure is described. It includes cutting slots into a smooth vertical wall, forcing wet dyed string into the slots and freezing it in. Results of one year’s installation are given for each of 13 grids installed throughout a 366 m. ice tunnel. Two important visual observations are reported. The first is that no differential shearing was found; and the second, that heavy dirt bands that occurred throughout the tunnel appeared to have extruded into the tunnel opening. A possible explanation is that dirty ice is more plastic than clear ice.

A microscopic method for the determination of particle-size distribution of pulverized snow was worked out. The method gives satisfactory distribution curves, presenting the number of particles as a function of their cross-sectional “areas”. The measurements were made by means of a filar micrometer eyepiece, the snow particles being placed on a ruled glass slide, which was submerged in silicone oil to prevent evaporation. The time for the determination of a distribution can be appreciably shortened by estimating the size of the particles instead of measuring them, though the accuracy is not so high in this case.

The general characteristics of the coastal regions between long. 45° E. and long. 80° E. are described. The features and conditions are similar to those found along the coasts of the Australian sector further to the east. Measurements of accumulation, snow transport, ice flow and ablation are described and results are given.

Accumulation, measured from stakes and pits, is 1.0 × 1014 gm./yr. in a 1 km. wide strip running 850 km. inland from the coast of MacRobertson Land. The methods of gauging drifting snow and extrapolating the results are given and a meridional mass transport of 0.16 × 1014 gm./km. yr. is deduced. Iceberg calving rates given in a previous paper are again quoted, although they are now felt to be too low. Net ablation is 0.053 × 1014 gm./km. yr. and additional evaporation above the firn limit accounts for 0.045 x 1014 gm./km. yr. The estimates are compared with old and new observations from other parts of Antarctica and the problem of bottom melting beneath ice shelves is discussed.

A distinction is made between the meteorological water budget for Antarctica and the glaciological mass balance for the ice sheet. Mass budgets for the sector between long. 45° E. and long. 80° E. and for the whole of Antarctica are drawn up. In each case a surplus of accumulation over losses appears, but it is felt that the data are insufficient to claim that the ice sheet is growing at the present time. The drift snow and ablation losses are added to the net accumulation to give a figure of 14 cm. of water as the mean annual precipitation over Antarctica, a value lying between the estimates of Meinardus and Kosack.

This paper is derived from notes on ice conditions made during a study of Captain James Cook’s voyage around Antarctica in 1772–75. The original notes comprised a detailed examination of the day-to-day remarks on ice in Cook’s Journal, together with comments in the light of present-day knowledge.

Detailed account of the work to be undertaken by the International Glaciological Expedition to Greenland during 1959, together with brief notes on the previous researches which have led up to this work.