Conical mounds of ice have been observed to form in a few hours during violent winter storms along the edge of shore-fast ice near Dunkirk, New York. They occur in lines which parallel depth contours, and are evenly spaced in the manner of beach cusps. The height and spacing of mounds and number of rows vary from year to year depending on such factors as storm duration and intensity, and the position of the edge of the shore-fast ice at the beginning of the storm.

The evenly sloping conical mounds have central channels which increase in width lakeward. The ice between the channels forms headlands above the lake surface. Spray-formed levees develop along the headlands and slope gently away from the lake margin. Lake marginal walls of ice are usually vertical.

Spray, slush and ice blocks are ejected over the cone as each successive wave is focused by the converging channel walls. Ice blocks, interlayered with frozen slush and dirt, form bedding paralleling the sloping surface of cones, headlands and levees. These features are here termed “ice volcanoes” because their origin is in so many ways analogous to that of true volcanoes.

The structure and flow field in the margin of the Barnes Ice Cap was determined through observations on the ice-cap surface, in four bore holes, and in a 125 m ice tunnel. A band of fine bubbly white ice with a single maximum fabric appears at the glacier surface about 160 m from the margin. This band is overlain by coarse blue ice with a four-maximum fabric, and underlain by alternating bands of fine ice with a single-maximum fabric and moderately coarse ice with a two or three-maximum fabric.

The effective strain rate was determined from the bore-hole and tunnel deformation data, and possible variations in the other three parameters in Glen’s flow law, , were studied. It appears that τxy is independent of depth near the surface, and that relative to the coarse blue ice, A is 40 to 50% lower in the white ice and possibly 10% lower in the fine blue ice.

Dips of foliation planes decrease rapidly with increasing depth and distance from the margin. This foliation is assumed to have developed near and parallel to the bed some distance from the margin. An analysis based on this assumption predicts the observed change in dip, but suggests that it did not develop under the present flow field. The ice cap was probably thicker a few tens of years ago, and the observed foliation pattern may be a relict from that time.

Seismic refraction and reflection shooting was carried out along three profiles about 10 km long, angled 60° to one another, near “Byrd” station, Antarctica, during the 1970–71 field season. No dependence of velocity upon azimuth was found, but velocities at 200 or 300 m depth were slightly greater than at a site 30 km away where measurements were made in 1958. The difference can probably be attributed to different ice fabrics arising from a 50% difference in snow accumulation rates at the two sites. The velocity depth and density–velocity functions at the two sites are also significantly different, but close agreement was found at each site between the depths to significant changes in the velocity gradient and the depths of fundamental change in the densification process. Such agreement may permit density–depth curves, and consequently accumulation rates, to be measured by seismic refraction shooting alone.

The reflection shooting on a common reflection-point profile led to a good determination of mean velocity through the ice as a function of angle of incidence. The results agree closely with similar measurements at the 1958 site, and with an anisotropic model based on glaciological and sonic logging observations in the deep drill hole. The mean vertical velocity of 3.90–3.93 km/s through the solid ice is about 2% higher than has commonly been used for determinations of ice thickness from seismic reflection shooting.

This paper puts forward an explanation of the origin of small marginal lakes (superglacial or moat lakes) occasionally found on the edges of valley glaciers. The explanation departs from earlier theories. On the basis of observations made on the Juneau Icefield in south-eastern Alaska, I have come to the conclusion that the lake basins are primarily blow-outs formed as a result of wind erosion.

The works undertaken on the Glacier d’Argentière in order to divert the subglacial stream, have allowed access to several natural cavities which correspond to places where the glacier loses contact with its rock bed. These cavities show a certain number of original phenomena both on the rock bed and also on the ice arch. Studies of the basal ice layer reveal peculiar characteristics which distinguish it from the rest of the ice mass: lamination, interstratification of ice containing sand with pure ice, crystallographic composition, and specific chemical composition.

The sliding speeds of the glacier are variable, and an increase in the friction below these cavitations is at the origin of a form of regressive glacial cavitation. The subglacial cavities are grouped together in a network transverse to the direction of glacier flow; they are interconnected by channels which are more or less open which allow proper thermal exchanges to be established and favour sliding.

A study of Hoseason Glacier was made to test whether photogrammetry could yield meaningful glaciological information from repeated series of air photographs without ground control. Three maps indicate that large time differences, different camera systems, and the use of sea ice as a level datum do not present insurmountable difficulties in photogrammetric reduction. Surface horizontal movement was determined and level profiles were compiled. Hoseason Glacier is probably in equilibrium.

The daily snow melt calculated from meteorological observations is compared with detailed mass-balance measurements taking into account internal changes in density and free water content in the surface layers of a glacier snow-pack. The energy balance is calculated from measurements obtained by a meteorological station at the experimental site. In addition to the standard ablation measurements the run-off from the melting snow-pack was obtained for a few days. The snow-density profiles were measured with a portable gamma-transmission probe and the liquid-water content of snow was determined by a calorimetric method.

Agreement between the melt calculated by the heat-balance method and the mass changes observed in the mass-balance measurements is fair for daily periods. It appears that about 20% of the daily snow melt takes place internally as a result of penetration of solar radiation.

With the aid of an atomic absorption spectrophotometer (Perkin Elmer 303), chemical analyses were performed on different types of ice collected in an enclosed natural subglacial cavity of the Glacier d’Argentière (French Alps). Contamination was reduced to background noise level of the instrument at each step of the procedure which was developed. One of the main problems encountered during the processing was the desorption of cations adsorbed on the surface of particles dispersed in the ice.

The mean composition in Na, K, Ca and Mg was established for glacier ice and for ice accretions hanging from the ceiling of the cavity or at the bedrock–glacier contact. The mean composition and the ratio (Na+K)/(Ca + Mg) of the ice accretions are higher than those of the glacier ice. This implies a refreezing of interstitial water which was enriched by desorption when, before refreezing, it was forced through the mud layer plastered at the base of the glacier.

Snow fences built up-wind of natural snowdrifts at four alpine sites in the Colorado Rocky Mountains changed snow accumulation appreciably. The 3 m tall fences increased the amount of snow at three sites but decreased it at the fourth. At two of the three sites where snow was increased, there was no change in melt rate, so the additional snow prolonged the melt period 1–3 weeks. Fences most successfully augmented natural snow accumulation at sites with level or gently sloping terrain down-wind from the accumulation site. Between 15 and 30 m of fence was needed to produce an extra 1000 m3 of water equivalent in the snowfields at the beginning of the melt season. Fences of the type described here, if properly located, are a means of increasing summer stream flow from alpine areas.

The mass transfer on an ice surface was measured using a groove decay technique on (0001) plane and <1010> direction at −10° C. The evaporation–condensation and viscous flow terms in Mullins’ theory were deduced from the change of decay constant as a function of groove wavelength between 16 and 80 μm. A viscous flow term contributes the most to groove decay while an evaporation–condensation term contributes up to 31.5% of the mass transfer for the shortest wavelength measured and other terms were found to be negligible. Large discrepancies between the decay constants obtained from the measurements and constants calculated from theory indicate that other mechanisms not considered in Mullins’ theory may be responsible for the groove decay.

A 51 mm diameter bore-hole camera allows observation of subglacial conditions, measurement of basal sliding rates, and study of internal structure and debris in ice at depth. The camera is simple in construction, field operation and maintenance. Water turbidity is a significant problem but it can be overcome by pumping.

Abundant specimens of lichens, including Rhizocarpon geographicum, are reported from an active medial moraine on Storbreen, southern Norway. The size and distribution of two crustose and two foliose species are described. Inferences are made regarding the age, origin and population dynamics of the lichens. Some implications of the observations for lichenometric dating and use of lichens as indicators of moraine stability are discussed.

Striated ground was found above 3 600 m elevation in the Páramo de La Culata, Pico Espejo and Pico Bolívar areas of the central Venezuelan Andes. This ground, formed by nocturnal freezing and diurnal thawing of the contained water, consisted of aligned lumps of fine to coarse sand, separated by small discontinuous channels (1–3 cm wide). Sorting was observed in the form of pebble-rich and pebble-poor zones. Striated ground in the process of formation showed that needle ice filled the channels before thawing. Lack of sorting is an indication of very recent formation, probably the previous night. The orientation of the striae is compared with the wind direction. This indicates that the formation of needle ice in the ground reflects the direction of the freezing wind, producing striae orientated in that direction, thus supporting Troll’s (1944) original observations.

Cylindrical samples containing 0.59 mm to 0.84 mm diameter silica sand at about 97% and 55% ice saturation (the ratio of ice volume to sand pore volume) were tested at a temperature of −12° C in triaxial compression. Both constant axial strain-rate tests and step-stress creep tests provide information on the influence of confining pressure on the shear strength and creep behavior of the sand–ice material. Changes in the degree of ice saturation help show the influence of the ice matrix versus the sand material on the mechanical behavior. Data are discussed in terms of the Mohr–Coulomb failure law and creep theories. It is shown that the cohesive component of strength depends on response of the ice matrix, whereas the frictional component of strength responds in a manner very similar to unfrozen sand tested at high confining pressures. Experimental data show that creep rates decrease exponentially and creep strength increases with an increase in confining pressure.

Comparative tests of the snow resistograph with the ram penetrometer indicate that there is a high degree of correlation between the two instruments despite fundamental differences in operation. It is probable therefore that the two instruments are measuring essentially the same parameters and may be used interchangeably. The resistograph has a large advantage over the ram penetrometer, in terms of speed and ease of operation, and in its capacity to measure the strength of very weak snow.

“Postglacial”, with a capital “P”, is a chrono-stratigraphical unit starting with the Preboreal at 10 000 B.P. De Geer used the same name for a period covering approximately the last 8 900 years. The same word “postglacial”, with a small “p”, is a genetic facies term telling us that the sediments were deposited without influence of the receding ice (in contrast to glacial deposits).

An abrupt change in radio echo sounding travel time was observed on the ice shelf near McMurdo station, Antarctica, and was mapped by a zig-zag traverse. This boundary corresponds to the horizontal extent of brine penetration into the edge of the ice shelf.

The Workman–Reynolds effect was studied in the growth of ice on a monocrystalline seed, at constant growth rates and under steady-state conditions, from KF solutions at concentrations from 2 × 10−5 to 10 × 10−5 Normal. Freezing potentials increased with growth rate to a maximum of 12 V at 11.2 μm/s. Discharge currents through a 105 Ω shunt generally increased with freezing rate until a maximum of 1.5 μA at 11.2 μm/s. The charge transfer decreased with growth rate to 200 μC at 10.3 μm/s and then reached a maximum of 850 μC at 11.2 μm/s. Apparent diffusion coefficients of about 2 × 10−3 mm2/s increased slowly with growth rate until a rapid increase began, apparently associated with interface breakdown. Distribution coefficients of the order of 10−3, calculated from a criterion for constitutional supercooling, increased with concentration. Parameters for LeFebre’s model of the interface showed an interface thickness of about 6 mm, an interface capacitance near one-half pF/mm2, and an interface resistance of about 6 × 104 Ω/mm2. Several empirical relations between these quantities were disclosed. Comparison with values obtained for KC1 solutions with the same freezing cell shows that the KF solutions yielded higher values of freezing potential, charge transfer, and distribution coefficient, and lower values of diffusion coefficient, interface capacitance, and interface resistance.