The relations between geodetic measurements of the surface level variations Δh and net budget measurements by stakes arc discussed. In 1961, 24 yr. after Finsterwalder’s survey, Tunsbergdalsbreen, the largest and most regular of the 26 outlet glaciers of Jostedalsbreen, was re-surveyed. The variations in the length, area, ice thickness, and volume of its tongue are shown. The lake Brimkjelen was 99 m. deep in 1937; it disappeared in 1949. From 1900–40 the whole Jostedalsbre lost 0.4 m./yr., about the same amount as the glaciers of the eastern Alps. The ice thickness of the Tunsbergdalsbre tongue diminished by −ΔhA = 0.46+0.0022 (1500−A) m./yr. from 1937–61; for the eastern Alps from 1920–50 −ΔhA ≈ 0.53+0.0021 (2850−A) m./yr. where A is the altitude. The change of Δh with altitude is much the same. The amounts of the retreat of the Alpine glaciers, of Tunsbergdalshreen, and at Werenskioldbreen, Vestspitsbergen, were the greater the higher the latitude. The numerical relations between Δh, net budget, and ice movement are shown. The temporary velocity transverse profile of 1937 served as a prototype for the streaming mode of flow, but in 1961 the glacier partially showed Blockschollen movement, although the velocity had decreased by more than 30 per cent. The article is accompanied by a map showing ice surface contours in 1937 and 1961.

All available 10 m. snow temperatures from the Greenland Ice Sheet have been analyzed using multiple regression techniques to develop equations capable of accurately predicting these temperatures. The analysis was carried out for all Greenland and for various sub-areas. The resulting equations show that 10 m. snow temperatures can be accurately predicted from the parameters latitude and elevation. Longitude was found to be a further significant parameter in south Greenland.

Gradients of 10 m. snow temperatures versus elevation for north Greenland are close to the dry adiabatic lapse rate indicating adiabatic warming of katabatic winds as the controlling mechanism in their altitudinal distribution. In both south Greenland and the Thule peninsula, gradients of 10 m. snow temperatures versus elevation are markedly greater than the dry adiabatic lapse rate and are highly dependent upon elevation, indicating downward transfer of latent heat in the snow, largely as a result of percolating melt water.

An isotherm map, showing the distribution of 10 m. snow temperatures on the Greenland Ice Sheet calculated from the prediction equations, was prepared. The map is based upon a revised contour map of the ice sheet made from a compilation of all known elevations.

Ice-surface and isopachous maps, and rock-elevation maps, were prepared for the area between the South Pole and the Horlick Mountains from seismic and gravimetric measurements. Basal shear-stress was calculated from these data and surface-slope measurements at 25 sites. The mean is 0.8 bar with an areal standard deviation of 0.5 bar. Forty-five values of average basal shear stress were computed from consecutive 30 km. segments along flow lines. The mean is 0.4 bar with an areal standard deviation of 0.1 bar. These variations are too large for accurate estimates of ice-thickness variations to be made from surface-slope data alone, following Nye’s suggestion that basal shear-stress be treated as constant. From theoretical considerations Nye demonstrated that surface features of wave-length less than 40 km. should disappear within a few months unless related to bed topography. Ice and rock profiles along a 220 km. line do not show an expected theoretical relationship. Surface-elevation measurements, repeated after a 2 yr. interval. showed the surface features with wave-lengths between 5 and 40 km. to be essentially unchanged in amplitude and position. Hence these features are not adequately explained by existing theory.

The net mass budget is estimated for the western part of the Ross Ice Shelf drainage system. The area of the system is (1.75±0.26) × 106 km.2, and the drainage periphery extends along the eastern flank of the Trans-Antarctic Mountains between lat. 77° 58′ S., long. 164° 37′ E. and lat. 85° 27′ S., long. 147°50′ discharge is estimated from vertical cross-sections and corresponding ice-movement data for eight outlet glaciers. Free-air gravity anomalies, corrected for the effect of terrain above the glacier surface, are used to determine cross-sections of valleys by comparison with theoretical gravity profiles for several two-dimensional valley models. These data provide a basis for estimating the rate of ice discharge from the plateau, which is compared with the estimated rate of net accumulation at the surface, to determine the net budget of the ice sheet in the region. Representative mean rates of ice discharge measured in different types of glaciers are approximately 0.25 × 1015 g. km.−1 yr.−1 in outlet glaciers with large basins, and 0.05 × 1015 g. km.−1 yr.−1 in outlet glaciers with small basins. Taking into account the snowshcd area and the rate of accumulation, the rate of ice discharge in cirque and piedmont glaciers is estimated at about 0.02 × 1015 g. km.−1 yr.−1 The difference ((48±29) × 1015 g. yr.−1) between mass input ((96±25) × 1015 g. yr.−1) and mass output ((48±15) × 1015 g. yr.−1) is large enough relative to the estimated standard error to indicate a probable positive net budget.

Velocity and ice-thickness profiles were measured un the western glaciers of the Sør-Rondane during the Expéditions Antarctiques Belges of 1959 and 1960 Some of the stations were re-occupied for velocity measurements during the Expédition Antarctique Belgo-Néerlandaise, Campagne d’Été 1964–65.

The profiles, with stations at 1 mile. (1.6 km.) intervals, were generally east-west and at right-angles to the direction of flow of the plateau outlet glaciers. The movement was measured by resection of each station from the main triangulation points over periods ranging from 256 to 1,501 days. Double ties with a Worden geodetic-type gravity meter were measured between the stations. An additional gravity station was occupied on rock at each end of the profile. The ice thickness and the subglacial topography are calculated from the gravity profiles. Combined with the surface velocity, they allow an estimate of the discharge of the glacier. The results indicate a close relationship between the glacier flow and the supply from the Antarctic Ice Sheet, as demonstrated by a study of the aerial photographs.

Nuclear magnetic properties of hydrogen are used for the quantitative analysis of the water content of sea ice from 0° C. to −40° C. The data on water content are utilized to calculate the brine volume and brine weight content of the samples. Over a range of water contents of 2% to 96% the standard deviation of the nuclear magnetic resonance data from chemical analysis data is ±0.6%, An estimate of water content in a sample of sea ice at −70° C. is given, and the value of nuclear magnetic resonance measurements for field studies is discussed.

The laws of wind-speed variation with height and their modification with stability are discussed and applied to observations in the first 2 m. over various cold surfaces. An exponential law is superior save in frequent, near-neutral conditions, but the logarithmic law is superior in neutral and again in really stable conditions. A power law and a logarithmic-plus-linear law give the best fit with the data only at moderate stabilities. A logarithmic-plus-cubic law of wind speed is evolved that permits suppression of linear additions to the logarithmic law at two distinct stabilities. A power form of variation of Richardson number with height is found and compared with a linear form. The former is applied with the logarithmicplus-cubic law to the observed data, though with limited success. Eddy-viscosity coefficients for the different laws are compared.

The average yearly net ablation rate on permanently ice-covered Lake Fryxell, Victoria Land, Antarctica, is 30 to 40 cm. This figure was calculated by a novel method utilizing a record of ablation which is incorporated in the ice cover of the lake. These values are higher than those measured on Ross Island 80 km. to the east; the difference in ablation rates for the two areas is attributed to the prevalence of katabatic winds in the climate of Taylor Valley. The Lake Fryxell ablation figure is applied to nearby Canada and Commonwealth Glaciers in the calculation of their ice budgets.

Investigations into the mechanism of dirt-cone formation, and snow patterning, are described. In each case the changes in patches of various materials arranged on a snow surface, were observed over a period of three weeks in the summer, under varying weather conditions. The effects of fine rock flour on the formation of dirt cones are analysed. Two main weather types are recognized as having different, but important, effects on the surface features of the snow; föhn-type winds, and calm, sunny conditions.

A consolidation theory is developed for an age-hardened snow under uniaxial stress in the porosity range of 35 to 55 per cent by considering one mechanism, viz. viscous flow of interparticle bonds. For a uniaxial stress σ the differential equation for porosity n in terms of time t is shown to be

where a and ν are structural parameters and η is the coefficient of viscosity of ice. Comparison of this equation and the integrated form with existing data predicts consistent and reasonable values for a. The predicted values of η/ν range from 10−2 to 102 times the published values for, η which may indicate that ν, and hence the consolidation rate, is greatly affected by the diagenetic history of the snow and the conditions of experimentation.

A consideration of possible expressions for the number and size of bonds intersected by a potential failure surface leads to the following expression for the strength of snow, σf, which is age-hardening at a constant porosity n:

where σi is the strength of ice, tf is the time at failure, α is a parameter specifically related to the mechanism of bonding, and ω is a temperature-dependent parameter. Allowing tf to become infinite provides the envelope of maximum strength for fully age-hardened snow at any porosity n.

During the period 8–19 May 1963 a preliminary field investigation was conducted in Greenland to determine the feasibility of using a nuclear technique to determine snow and ice density profiles. A standard nuclear soil-moisture depth probe was used with two modes of processing and recording the nuclear pulses. Example data are compared with snow densities obtained by the standard weighing technique. The nuclear method was found to be feasible; however, deficiencies related to poor resolution render the probe unusable for detailed profiling of snow stratigraphy in its present form, but expected progress in nucleonics should enable improved resolution and accuracy to be achieved by improvement of nuclear detectors.