A simple technique for measuring the pressure in individual bubbles of gas in glaciers is described. By this technique, bubble pressures in twenty-six west Greenland icebergs were measured. The bubbles were for the most part tubular in shape and oriented parallel, lending a fibrous and sometimes stratified appearance to the ice. Various suggestions are offered for the formation of these bubbles. Most bubbles had a pressure of 4–5 atmospheres, and pressures as high as 20 atmospheres were recorded. In closely adjacent bubbles differences of 2–5 atmospheres were often measured, which indicated diffusion tightness and lack of plasticity in the ice. When the ice surface melts, the bubbles expand at the cost of water extrusion. The various factors contributing to the maintenance of vertical walls characteristic of tabular bergs are discussed.

The techniques of avalanche forecasting and control have found increasingly wide adoption in North America in the past decade. Numerous government and private agencies are now engaged in work to protect ski areas, highways, railroads and power lines. Practical control measures such as artillery fire have been developed to a high degree of effectiveness, but the construction of permanent defense structures other than snow sheds is still in its infancy. Experimental work on instrumentation, forecasting, defense structures and the use of explosives, artillery and jet aircraft is currently in progress.

Contributions to the glaciology of the Himalaya, Karakoram, and Turkestan areas are contained in the hitherto unpublished records of the Schlagintweit brothers. These should be of considerable value for future research since the records include paintings, sketch maps, descriptions, and also measurements of glacier speed, which give details of the state of the glaciers in 1855–56. These records were used recently to great advantage on Nanga Parbat.

These notes are based on observations made in 1958 while the writers were members of the Birmingham and Exeter Universities Spitsbergen Expedition. The position of the ice front in 1958 is compared with that recorded on five previous occasions between 1882 and 1936. A rapid 6 km. advance at the end of the nineteenth century has been followed by a slower but equally extensive retreat. A revision of the limit of maximum advance is based on geomorphological evidence. Reasons are suggested for the relatively small changes in the outline of the ice front since 1927, and the effects of spells of moderately high atmospheric pressure are noted.

Observations made of ice crystals growing on the surface of supercooled water show that they take the form of a composite structure, called surface needles, each of which consists of dendrites growing into the liquid, and of ribs growing in the liquid surface. Each needle is a single crystal. The precise form of the needle is determined by the orientation of the initial nucleus. If its optic axis is near normal to the surface, growth occurs rapidly in two dimensions and covers a much larger proportion of the surface than is covered by the narrow surface needles, so that ice forming this way appears to have its optic axis vertical. Hollow ice spikes observed on pools are shown to have been formed by the freezing of water forced from beneath the surface at the intersection of two or three surface needles, the shape of the spike depending on their orientation.

This paper is a synopsis of Falkland Islands Dependencies Survey Scientific Report No. 29. Glaciological and climatic investigations carried out in South Georgia during the International Geophysical Year are described. The budgets of the Hodges and Hamberg Glaciers for 1957–58 are given and discussed in relation to climatic factors. Temperature measurements indicate that the Hodges Glacier, and probably all ice in South Georgia below an altitude of 1,000 m., is geophysically temperate. The fluctuations of South Georgian glaciers during relatively recent times are briefly discussed.

As a result of an historical sketch of scientific activity on Mount Washington, New Hampshire, it is shown that the late-season snow-bed that annually forms in Tuckerman Ravine disappeared, on the average, during the first week in August for the period 1922–58 as compared with an average date of 11 August for the period 1878–1906. This appears to correspond to a rise in spring (April to May) and summer (June to September) mean temperatures of 0.9° F. (0.5° C.) for each season from 1872–87 to 1933–58. The snow-bed probably has persisted through only one ablation season during recent years, that of 1926, although some evidence exists that it may have lasted through an occasional summer during the early and middle nineteenth century.

Curious interlocking thrust structures, described in the Journal of Glaciology, Vol. 3, No. 23, 1958, p. 173–75, are shown to be a common and typical deformation feature of young sea ice, and a suggestion is put forward as to their formation.

Observations of the snow depth at 21 sites at Resolute were made twice weekly during the winter of 1957–58. As a result of these observations, and of other observations on snow made for the National Research Council, it is shown that the snow depth and the water content of the snow did not continue to increase during the winter as the snow fell. Rather the strong winds eroded the snow surface and the increase in depth was irregular and relatively slow. Furthermore, the observations on the density of the snow cover lead to the conclusion that attempts to measure the density in similar regions with an accuracy greater than ± 0.05 g. cm.−3 are not warranted.

Thermal considerations affecting the rate of formation of sea ice are discussed showing the effects of the major variables. The natural solidification process (freezing downward from contact with cold air) is contrasted with freezing of layers cast on the surface of sea ice. Transient heating and cooling of solid ice during and after flooding are analyzed. Procedures for maximizing the rate of ice formation and minimizing base-ice heating are discussed, along with factors affecting brine segregation.

The seasonal precipitation of Ruwenzori is examined and the height of the climatic snowline determined. Two distinct periods of surplus accumulation and two ablation seasons can be recognized and give rise to a somewhat complex stratification. Precipitation diminishes with altitude above about 10,000 feet (3,050 m.). The water equivalent of the annual accumulation on the highest peak is thought to lie between 25 and 30 inches (635–762 mm.). Twelve months’ synoptic charts have been analysed and an attempt is made to relate the seasonal variations of accumulation and ablation to the meteorological factors accompanying the oscillations of the Inter-Tropical Convergence Zone.

Measurements of ice temperature to depths of 30–40 m. are given for a number of points on the ice sheet in MacRobertson Land. Variations of mean surface temperature with elevation and with latitude, and the temperature gradients below a depth of 15 m. are compared with results from other parts of Antarctica and from Greenland. Explanations of negative temperature gradients near the surface of ice sheets are reviewed, and an equation derived by Robin is checked against the measurements following its recent justification from conduction theory. Surface ice velocities necessary for development of the observed temperature gradients are computed, and these values are then compared with ice velocities estimated independently from flow measurements at the coast and continuity considerations. It is found that, if negative gradients are attributed solely to the Robin effect, improbably high ice velocities are called for, and so climatic change is reconsidered. Some evidence of secular warming in Antarctica is mentioned and a recent numerical solution of the conduction equation for the surface-warming case is described. It is concluded that the measured temperature profiles can be explained reasonably by climatic amelioration.