The lemniscate loop, previously employed in the approximate generic description of the shapes of erosional drainage basins, is shown to bear a close genetic relationship to streamlined forms. This is illustrated by comparison with the shape of airfoils, the snowdrift and certain eggs. Drumlins have been recognized as similar streamlined forms and the lemniscate loop is suggested as providing a quantitative genetic description of their shapes.

The compressive strength of snow cylinders was investigated as a function of the age of the snow from which the cylinders were made, the snow particle size and the age of the cylinders. The results show that the compressive strength is reduced if the snow is older, if the particle size is smaller, or if the cylinders are younger. The variation with age of the cylinders can be represented by an equation similar to that for a first-order chemical reaction. The effect of adding small quantities of various gases to the atmosphere in which the cylinders were kept was also investigated; carbon dioxide and methane had no measurable effect, but ammonia lowered the strength of the cylinders. All the strength measurements were carried out at −10° C.

The object of the 1957 program of the Juneau Ice Field Research Project on Lemon Creek Glacier was (1) to obtain data on surface movement in the accumulation region, and (2) to relate the movement to the average annual hydrological budget. Results show a net loss of ice over the past four years, although this deficit does not appear to be reflected by the movement of the ice. Lemon Creek Glacier appears to be in approximate equilibrium.

The expedition to Mauna Loa in Hawaii was undertaken in the winter of 1956–57 in order to study the nature of snow crystals in the district where the fewest aerosol particles are present. 170 photomicrographs of snow crystals were taken at the summit—13,450 ft. (4000 m.). The varieties of snow crystals were abundant and almost all types hitherto known were observed. The characteristic of the snowfall was the abrupt transition of one type to the other. Many single needles were observed, which were very rare in Hokkaido. Two new types were found; one was a needle composed of many hexagonal columns, and the other an elongated column which is the intermediate state of needle and column. Several photographs were obtained which show the mechanism of formation of ice pellets.

Small glaciers lying in funnel-shaped hollows on steep slopes have been variously described as wall-sided glaciers, cascade glaciers, cliff glaciers and niche glaciers. This type of glacier and the landforms associated with them in Bünsow Land, central Vestspitsbergen are described and their possible mode of origin is discussed. The theory that they were formed by an overspill of plateau ice and that they are thereby genetically related to hanging glaciers is rejected. It is suggested that they are formed by an accumulation of snow in an initially water-worn gully and that as the small glacier develops the original form of the gully is modified by nivation to a rounded, funnel-shaped hollow. Niche glaciers may thus be considered as glacier types genetically related to cirque glaciers, forming an early stage in corrie development.

A number of measurements of ice flow in the coastal regions of Antarctica are given. Observations show that the general outward movement of the continental ice, termed “sheet flow”, is locally accelerated where “ice streams” are formed. Estimates indicate that ice streams, which only occupy a small fraction of the total length of coast, are responsible for the removal of more ice from the continent than the “sheet flow” over the remaining length of coast. Further estimates suggest that the great bulk of Antarctic icebergs are produced by ice shelves, but that data on ice shelf movement are inadequate at the time of writing.

Measurements have been made on Austerdalsbreen, Norway, to test the theory that wave ogives at the foot of an ice fall are formed by pressure. The pattern of deformation over the first three waves from the Odinsbre ice fall was studied by measuring the absolute and relative motions of 35 stakes during August 1956. There are large variations of longitudinal compression through the wave pattern, but no simple correlation exists between the compression and the crests; nor are the crests consistently rising with respect to the average surface. We conclude that the waves are not forming by pressure in this area. A detailed quantitative explanation of the observed pattern of deformation is found by improving the existing theory of glacier flow. The deformations taking place are explained as essentially independent of the presence of the waves; they are primarily due (a) to the compression that must occur in the ice as its slope decreases and it becomes thicker, and (b) to the bending and unbending to which the ice is subjected as it passes over a bed of changing curvature. Additional contributions to the deformation arise from the widening of the glacier channel, which is important at the immediate foot of the ice fall, and from the annual ablation.

The theory explains quantitatively the rotation and bending of the tunnel excavated in 1955; it was also used to make a prediction, which was successfully verified in a further experiment on the glacier in July and August 1957.

A pressure mechanism of wave formation can be reconciled with the observations if it is supposed that the compression in the lower two-thirds of the ice fall, which was measured photogrammetrically in August 1956, varies significantly with the seasons. However, the positions and amplitudes of the observed waves are fully accounted for by the combined plastic deformation and ablation mechanism recently described in another paper. There is therefore no longer any need for the pressure hypothesis as a primary cause of the waves.

The rate of strain tensor at a point on the surface of a glacier may be determined by setting up a number of stakes in a pattern and measuring the rate of change of the distances between them. A suitable pattern consists of four stakes at the corners of a square with one stake at the center. Five such patterns were used on Austerdalsbreen, Norway, in August 1956. The problem is to deduce the best values of the 3 independent components of the strain-rate tensor from the 8 measured quantities, and, for this purpose, a least-squares method, invented by Bond for the analogous problem in crystal physics, is used. The principal strain-rates are found to within about ±0.005 yr.−1 and their directions relative to the stake system to within about ±0.5°. The directions and magnitudes of the principal stresses are then deduced from Glen’s flow law and a suitable general theory. The directions of the principal strain-rates are in good agreement with the directions of the crevasses, but the experiment is inconclusive on the question of the magnitude of the stress needed to form a crevasse.

In a 300 m. deep hole drilled in the 3000 m. thick ice at Byrd Station (lat. 80° S. long. 120° W., 1513 m. above sea-level), the temperature was observed to decline with depth below 45 m. This profile was extended to the bottom of the ice with the aid of heat conduction theory under these assumptions:

• i. that as the ice was deposited the climate became warmer at the rate of 045° C. per 1000 years;

• ii. The conduction of geothermal heat is 31.6 cal. cm.−2 yr.−1.

It is estimated that the first 2000 years of geothermal heat conducted to this ice, whose annual accumulation is 30 cm., is dissipated to the atmosphere and space. When the ice becomes thicker, it retains all the geothermal heat given to it for a long time.

An alternative, non-climatic change explanation of the decreasing temperature in the Byrd Station hole is based on colder ice from higher elevations moving under the warmer ice accumulated locally. However, an examination of the topography of the Marie Byrd Land ice does not appear to support this explanation.

At the inland station “Southice” (at approximately lat. 82° S., long. 29° W.) investigation in firn to 45m. included profiles of temperature, density, granularity and crystal size. Mean annual accumulation and temperature are interpolated and crystal fabric analyses briefly discussed. A study of drifting snow is outlined.

Similar studies, but without crystal observations, were continued across the continent using snow cores to 11 m. depth and supplemented by Rammsonde soundings. These sub-surface observations with the sastrugi forms noted, permit the interpolation of the mean accumulation, temperature and wind direction at different heights across the continent. Radiation flux, wind speed and air and snow temperature profiles were recorded at various halts.