The ice movement on the Byrd Glacier, Antarctica, was measured as function of time, on the basis of aerial photography. The method of aero-levelling strip triangulation with a minimum of geodetic control was applied. The methods and procedures were verified over Laufen-Bauma test area.

The seasonal distribution of snow at the South Pole and its relationship to stratigraphy was investigated to pits dug beside a number of four-year-old accumulation stakes. Results show that conventional stratigraphic methods yield thoroughly reliable values of accumulation rates. Even hiatuses in accumulation can be identified from the intensity of sublimation of layers of depth hoar in the stratigraphic section. Such hiatuses are due almost invariably to the prolonged absence of accumulation rather than to widespread scouring of pre-existing layers of snow. The bulk of the year’s accumulation is deposited as dunes during winter. The majority of dunes are subsequently transformed into linear sastrugi by wind with the result that the amplitude of surface relief observed at the end of winter frequently exceeds the average thickness of snow accumulated annually. Such gross relief does not persist to the end of summer, however. Instead the dunes and sastrugi arc gradually worn down by a process of sublimation-deflation. It is this leveling of the surface relief in summer and the resultant redistribution of snow more uniformly over the surface that are believed to be the significant factors in the formation of the systematic stratigraphy observed in pits at the South Pole.

Observations in a deep mine working which reached the base of a valley glacier some 150 m. below the ice surface indicated an initial cold and impervious condition at and near the ice–rock contact. Later, however, an excellent hydraulic connection with free water in the upper layers of the glacier was established, perhaps by the thawing of a passage upward through the ice by warm water escaping from the mine. Subsequent records of water levels, or of water pressures, within the mine, reflecting conditions in the upper part of the glacier, show periods of moderately steady conditions, at times showing slight diurnal fluctuations, interrupted by irregular and catastrophic surges, particularly during periods of rapid snow melt and heavy rains. A seasonal cycle in pressure is suggested by the record.

Young’s modulus E and Poisson’s ratio σ0 were calculated for biennial and polar ice from measurements of the P-wave velocity in small samples and from a study of the resonant frequencies of the saure samples. P- and S-wave velocities in the biennial ice cover were also found by a seismic method. The small-scale tests showed no significant differences between the two types of ice tested. Young’s modulus averaged 3.6 per cent lower than the comparable figure for annual sea ice. The seismic method gave values of E and σ0 about 20 per cent lower than the small-scale tests.

Early photographs of a cirque glacier complex in the Arrigetch Peaks of the south-central Brooks Range date from 1911, and are the second oldest known set of glacier photographs from northern Alaska. Matching photographs and supplementary observations made in 1962 indicate that changes over the past 51 yr. in this area include general glacial recession and thinning, the emergence of pronounced trimlines and partial melting of ice cores beneath recent moraines.

Renewed post-hypsithermal glacial activity in the Arrigetch Peaks area attained two maxima in the recent past. The younger moraines lie close to glacier positions shown in the 1911 photographs, contain ice cores which extend practically to their surfaces and were probably formed in the latter part of the nineteenth century. More weathered deposits, underlain by ice cores at relatively greater depths, were formed at some unknown earlier date. The moraines are correlated with the two-substage recent Fan Mountain advance of northern Alaska and may correspond to dated mid-eighteenth century and middle to late nineteenth century advances of alpine glaciers in the north Pacific coastal mountains of North America.

Two types of rock glacier occur in the Colorado Front Range. Rock glaciers on the floors of modern cirques closely resemble the tongues of small valley glaciers. Because they contain cores of banded glacial ice and grade up-valley into lateral moraines, rock glaciers of this type are believed to represent the debris-covered tongues of former glaciers. Most consist of two or more superimposed lobes, bounded by longitudinal furrows, and resulting from independent ice advances. Despite their compound nature, the complexes now appear to be moving down-slope as single units. Two generations of “cirque-floor” rock glaciers, both tentatively dated as being of post-Pleistocene age, occur in the Front Range.

Rock glaciers of an entirely different character occur beneath steep valley walls, where they are supplied with debris by avalanche couloirs. Interstitial ice, responsible for the movement of “valley-wall” rock glaciers, probably results from the metamorphism of snow buried beneath rock-fall debris or supplied by winter avalanching.

As an extension of an intensive study of Gulkana Glacier a 42 station gravimeter survey was made to gain some insight into its third dimension. This survey showed that the glacier’s main tongue occupies a complex valley composed essentially of two parallel channels separated by a medial ridge which extends southward from rock bastions in the accumulation zone. At mid-glacier the ice thickness in the larger eastern channel is 225 m., in contrast to 130 m. in the western channel. The medial ridge degenerates down-glacier probably disappearing within 2 km. of the glacier terminus. The basic surface flow pattern of the glacier described by Moores can be adequately explained by this basal topography. Seasonal velocity variations are possibly caused by melt-water basal lubrication with one channel being favored over the other at different times of the year, in agreement with observations by Elliston on the Gorner-Gletscher, Switzerland, and with the glacier sliding theory of Weertman.

The custatic changes of the ocean in prehistoric and historical times are linked with the fate of the ocean-based salt industry, and are recognized as erratic. An hypothesis is proposed to explain these erratic changes with albedo changes of the polar ice sheets, caused in turn by erratic volcanic dust fall-out. Ash layers in Antarctic ice cores are connected with historical dislocations of maritime civilizations.

Albedo changes associated with the dusting of ice sheets are considered to be the cause of the decline of periods of glacierization generally. Such albedo changes are connected with volcanic activity on the one hand, and loess formation on the other, caused in turn by the growth of the ice sheets.

Gravity measurements have been used to determine ice thicknesses across the western part of the Devon Island ice cap in the Canadian Arctic. A detailed profile of the ice-cap edge and a profile across an adjoining glacier are also given. The ice cap has been found to have a largely rock core with ice thicknesses generally less than 500 m. A deep valley has been found in the bedrock beneath the ice cap some 15 km. from the start of a draining glacier. The measured depths on the ice cap should be within 15 per cent and those on the glacier within 20 per cent of the true values.

At lat. 7° S. the fern line was at about 3,500 m. during the Riss glaciation, at 3,650 m. during the Würm maximum and at 3,700 m. during a later stage (Würm II?). The moraines were deposited by equatorial-type glaciers from which there was relatively little melt water.

At lat. 14° S., during the Riss glaciation, an important ice cap covered a 3,900–4,000 m. high plateau, the firn line being at about 3,950 m. The role of melt waters was important in the formation of the moraines, suggesting their deposition from tropical-type glaciers. From the evidence of periglacial gravels it appears that this southern region has not been glaciated since Riss times.

Numerical solutions are found for the steady rectilinear flow of ice, obeying Glen’s non-linear flow law, down uniform cylindrical channels of rectangular, semi-elliptic and parabolic cross-section. The results are also directly applicable to the pumping of a non-Newtonian fluid down a pipe. There is assumed to be no slip of the ice on the channel surface. Certain results on the centre-line velocity in symmetrical channels may be derived purely from dimensional and symmetry principles. An analytical solution due to Dr. W. Chester is given for a semi-elliptic channel section which departs only slightly from a semi-circle. Contrary to a view sometimes held, the maximum shear stress at the ice surface in a parabolic channel and in some elliptical channels does not always occur at the edge. With the flow law, strain-rate proportional to (stress)3, the velocity averaged across the ice surface, which is easily measured with a line of stakes, is close to the average velocity over the whole section for a wide range of parabolic sections; the hydrological importance of this result is that the discharge may be inferred without the need to measure the velocity at depth. Arguments are given to show that the result still holds when there is slipping on the bed and when the power in the flow law differs somewhat from 3, Depending on the amount of bed slip and the shape of the channel section, the kinematic wave velocity for a range of parabolic channels is between 2.0 and 2.3 times the centre-line velocity of the ice, and between 2.0 and 3.5 times the mean surface velocity of the ice.

Karst topography may occur on stagnant, drift-covered parts of glaciers such as the Martin River Glacier in south-central Alaska. Glacial karst features there include ice sink-holes, tunnels, caves, sinking streams, blind valleys, large springs, natural bridges, lapiés, hums, and residual “soils” or ablation till. The glacial karst cycle is essentially the same as the limestone karat cycle. Glacial karst is rare today but was widespread on stagnant glaciers in areas such as the northern Great Plains of North America in late Wisconsin time.

In the summer of 1962 a completely portable and relatively simple electrically heated thermal core drill of new design was constructed and used to obtain 16 oriented samples of ice 2.5 cm. in diameter by 120 cm. in length from depths ranging from 12 m. to 137 m. in lower Blue Glacier, Mount Olympus, Washington, U.S.A. The thermal element is a 0.260-in. (0.66-cm.) diameter 300-W. 150-V. tubular heater bent to form an annulus with an external diameter of 5.0 cm. Opposed ratchet-like teeth break off and hold the core inside the tubular core barrel. Orientation is recorded photographically by a commercial inclinometer modified to show azimuth and to be controlled from the surface.

The earthquake of 27 March 1964 in Alaska created a great number of rock avalanches which discharged onto the glaciers from the surrounding mountains. The ice falls became much more broken up than normal but the remainder of the surface of the glaciers was largely unchanged except for more open crevasses than before the earthquake.

In the Kumaon region of the outer Himalayas there is a chain of lakes which, on the basis of various features, were previously thought to be of tectonic origin. A detailed geological study of this area carried out in June 1961 revealed the presence of morainic deposits in the vicinity of the lakes, and it is now considered that they are essentially of glacial origin.

Structures produced by chemical etching on the basal plane of ice crystals have been studied and are discussed in terms of non-basal glide features. Slip bands, revealed by parallel rows of etch pits, generally result from a rapidly applied stress. Etch channels were observed relatively rarely in these experiments; they can be interpreted as trails of dislocations moving slowly under the action of local stresses, sometimes to stresses produced during the etching process. Features of the channels indicate that the dislocations emerging on the basal plane are screw dislocations; their Burgers vector was considered by previous authors to be in the direction <1123>, gliding on {1122}and {101o} slip planes. This assumption is inconsistent with the changes of channel direction we observed, for which the {0111}and {2421}slip planes would have to be considered. As a simpler hypothesis the glide system 〈0001〉, {101o} and 〈0001〉, {1120}is proposed.

During the summer of 1963. a drift-veneered mass of ice suddenly emerged at the surface of “Miller Lake”, art ice-walled lake at the terminus of the Martin River Glacier, Alaska. Subsequent fathometer traverses, together with the fact that the ice was not at the pressure melting point, revealed that it had been derived from a hole approximately 40 m. below the surface of the lake. There are numerous large debris-covered icebergs in the lake and presumably at least some are formed in this manner. Others are derived through differential ablation of projections of the glacier into the lake. Only the small icebergs are formed through calving. The interpretation of the mechanism of release of ice from the bottom of the lake, and the observation and interpretation of a rising ice-cored island in the same lake suggest that the ice on the bottom is deforming plastically and that it is undergoing compressive flow. Much of the movement may be along shear planes actually found in icebergs derived from the bottom of the lake.