The effect of a basal water layer on the equilibrium dimensions of an ice sheet is examined. A thick water layer can decrease the equilibrium thickness of an ice sheet such as covers Antarctica (which contains no significant ablational areas) by a factor of the order of 2. Similar large changes in the equilibrium dimensions occur for ice-age ice sheets (which have extensive ablation areas). The extent of the ablation area of an ice-age ice sheet which may be covered with morainal debris is also calculated.

A portable first-arrival seismic refraction instrument was used to measure seismic P-wave velocities in ice, frozen ground, till and shattered rock at various places in the McMurdo Sound region, Antarctica. It was found that some frozen ground exhibits the same seismic velocity as ice, so that buried ice cannot be idengified by seismic velocity measurements.

The depth of exfoliation of a granite outcrop in Taylor Valley was successfully measured, as was the depth of an ice-free moraine in Wright Valley. From this latter depth, and from reasonable assumptions about the diffusion of water vapour through till, a minimum age of 75,000 yr. has been deduced for the moraine. This age implies that no through-glacier occupied Wright Valley during the last Northern Hemisphere glaciation.

The firn stratification in the accumulation area of an alpine glacier was studied in a 20 m. deep, vertical pit dug in the summer of 1963 on the Kesselwandferner (3,240 m. above sea-level in the Ötztal Alps). The firn is traversed by ice layers up to 25 cm. in thickness which have been formed by the damming up and freezing of melt water. Firn density increases with depth. At a depth of 13 m. (8 yr. old firn) the density reaches 0.80 g./cm.3 as a mean value of one annual net accumulation. Excluding the ice layers, the firn reaches a density of 0.82 g./cm.3 in a 10 yr. old layer at a depth of 16 m. The firn stratification in relation to seasons was studied by analyses of the pollen content in the lower part of the pit, beginning with the horizon “late summer 1954”. The late summer horizons obtained from the firn stratification were confirmed by the pollen analyses.

Firn samples from a 20 m. deep pit were examined by pollen analysis methods in order to confirm the stratigraphy of the annual net accumulation back to 1949. The late summer horizon separates the overlying winter layer with a small pollen content from a firn layer with a large pollen content. There are also differences in the spectra of the species which enable a seasonal separation of the layers. In addition, the mineral dust content was examined.

Attenuation of visible radiation by falling snow was studied by a method based on brightness contrast between topographic features and the adjacent sky. Extinction coefficient and visual range are related to bulk snow density, and are compared with data for Antarctic blizzards. Since attenuation depends more on the size and concentration of discrete particles than on the mass density of suspended snow, the process of particle aggregation and snow-flake formation during fall is considered by collision theory, and an expression describing aggregation effects is developed. This offers an explanation for the relative constancy of particle concentration observed at ground level during snowfalls of varying intensity. Since there is no strong justification for relating extinction coefficient to snow density, an empirical correlation between extinction coefficient and precipitation rate is given for practical use. It is shown that visual range estimated by eye in hilly terrain may be less than the true value, since sky brightness is locally reduced over broad hill-tops with low albedo.

Two types of morainic deposits can be found in western Sør-Rondane mountains: the super-glacial morainic ridge the material of which comes from slope evolution, and the hillocky moraine whose origin is related to shear planes in the glacier and therefore subglacial. A hypothesis of the formation of the hillocky moraine is given and the lithological composition of this deposit allows us to deduce the importance of glacial erosion at the level of the ice falls which frequently exist at the beginning of outlet glaciers where they leave the polar ice sheet. On this step, the role of glacier fluctuations is of importance in relation to a special periglacial process: greenhouse frost shattering.

The mathematical theory of heat conduction is applied to the analysis of ice segregation processes in soil. A diffusion equation is first employed for the flow of soil moisture. Two new quantities, the rate of ice segregation,σ and the segregation efficiency, E, are introduced. The first is the rate of ice growth measured as mass per area per time. The latter is defined as E = σL/(K1∂T1/∂x−K2∂T2/∂x), where L is the latent heat of fusion of ice, T1and K1are the temperature and thermal conductivity of frozen soil, and T2 and K2 are the temperature and thermal conductivity of unfrozen soil. Three types of soil freezing can be classified in terms of E: freezing of non-frost-susceptible soil (E = 0), perfect segregation (E = 1) and imperfect segregation (0 < E < 1). Finally, the mathematical boundary conditions at an advancing frost line are obtained in freezing, frost-susceptible soil (E ≠ 0). Two parameters related to the structure of soil are pointed out, which seem to be valid criteria of frost susceptibility. The amount of frost-heaving is derived under special conditions.

In South Wales there is evidence for two phases of intense glaciation and an interglacial phase during the Pleistocene. During the closing stages of the earlier glaciation in the west of the Vale of Glamorgan two overflow channels were cut by melt water from an ice lobe off the Glamorgan upland, abutting against ice from the Irish Sea. During retreat, ice from the Irish Sea and local ice deposited material on the Lower Lias outcrop on which two contrasting soils developed. Soils normally associated with a Mediterranean climate developed locally on the outcrop of the Carboniferous Limestone during the interglacial phase.

Meteorological observations were made on Lewis Glacier, Mount Kenya, during the “long rains” in April 1960. General meteorological observations indicated rather similar conditions to those found in other months. Ablation occurred on each day but amounts were generally small. Rather more accumulation occurred than is expected during the dry season, but again amounts were small. The net accumulation over a to day period was only 0.38 cm. water-equivalent, although about 30 cm. new snow (about 10 cm. water-equivalent) was lying when the expedition arrived. Detailed observations of short-wave radiation, temperature, wind and humidity with estimates of long-wave radiation were used to calculate the heat balance at the surface of the upper ablation region. Agreement between calculated and measured ablation was reasonably good. Over the periods considered, radiation accounted for 89.5 per cent of ablation, turbulent exchange from the air for 8.0 per cent and evaporation for 2.5 per cent. Subsurface melting was taken into account and the formation of ice bands in terms of such melting is discussed.

Advantages of neutron moisture probes over standard snow sampling tubes include integration of water content over a greater horizontal extent, easier measurement of snow layering, and possible increase in accuracy through elimination of the need to extract a full core. However, the neutron probe is better suited for evaluation of water content changes with time at a fixed location, as in soil moisture studies, than for measurement of the total water content of a variable snow pack. Field tests in the mountains of Idaho, U.S.A., showed statistically significant differences among mean snow densities determined by a neutron probe in closely spaced holes at a single sampling station. Within-station variance was about the same as with a conventional snow tube. There were significant differences in density for a given depth from hole to hole, but statistical interactions make it difficult to interpret these differences. There was a poor correlation between measurements made in the same hole with a neutron probe and with a snow sampling tube.

A device is described which gives direct measurements of the rates of accretion of ice on both the top and the bottom of lake ice without the necessity for repeated drilling. A method for measuring the hydrostatic water level is also described.

A description of the two glaciers n. Bogbre and s. Bogbre is given. In summer 1965 snow pillars capped with avalanche material were seen. A blister-shaped swelling which appeared on the surface of s. Bogbre and which emitted water when punctured is discussed.