Investigations of isotopic and temperature profiles in polar ice sheets were mostly carried out independently of one another until 1973 when a workshop dealing with both topics was held in Cambridge. Studies of temperature profiles show the approximate validity of theoretically derived temperature distributions for steady-state models of ice sheets, while other analyses help to determine departures from the steady state. The review gives some idea of the degree of accuracy of various solutions arising from studies of the heat flow and temperature distribution of ice sheets. Much of this knowledge is directly applicable to interpretation of isotopic profiles if a direct correspondence between mean isotopic δ values and mean annual temperatures can be established. The paper therefore reviews various methods of comparing δ values and temperatures, and shows that for central regions of polar ice sheets a reasonably consistent relationship between these factors does exist.

The Transantarctic Mountains of East Antarctica provide a new milieu for retrieval of ice-core records. We report here on the initial findings from the first of these records, the Dominion Range ice-core record. Sites such as the Dominion Range are valuable for the recovery of records detailing climate change, volcanic activity, and changes in the chemistry of the atmosphere. The unique geographic location of this site and a relatively low accumulation rate combine to provide a relatively long record of change for this potentially sensitive climatic region. As such, information concerning the site and general core characteristics are presented, including ice surface, ice thickness, bore-hole temperature, mean annual net accumulation, crystal size, crystal fabric, oxygen-isotope composition, and examples of ice chemistry and isotopic composition of trapped gases.

A technique to estimate undisturbed ice temperature is discussed for sensors placed in boreholes that have been heated to the melting point during drilling, and for which only a limited time span of temperature record is available. A short temperature record after the hole refreezes commonly results when using hot-water or steam drills, where measurements are constrained by logistics, ice deformation, sensor drift or other problems, or where the refreezing time is long because of near-freezing ice temperatures or large hole sizes. Short data records are also typical in ongoing drilling programs where temperature information may be necessary for the program itself. Building on analyses by Lachenbruch and Brewer (1959) and a numerical model by Jarvis and Clarke (1974), it is shown that estimates of undisturbed temperatures can be made from records of temperature that extend only marginally beyond the initial refreezing. Complex effects of hole size, heating history, and the thermodynamic and geometrical effects of a moving boundary (the freezing borehole walls) are important to temperature decay immediately after freeze-up, so that the standard technique of comparing temperature decay to an inverse of time model is not applicable, and comparsion has to be made to a numerical model of heat flow to a refreezing borehole. Data from Ice Stream B, Antarctica, are compared to the numerical model to illustrate the technique. Data are also compared to simpler (inverse time) thermal models, and a potential for error is pointed out, since a short data record can be spuriously matched with the simpler, one or two free-parameter, models.

During ice-structure interaction, ice will fail in a brittle manner dominated by two processes. The first corresponds to the formation of macrocracks and the consequent spalling-off of large ice pieces. The second includes an intense shear-damage process in zones, termed critical zones, where high pressures are transmitted to the structure. The shear-damage process results in microstructural changes including microcrack formation and recrystallization. A range of tests on laboratory-prepared granular ice have been conducted to determine the fundamental behaviour of ice under various stress states and stress history, particularly as it relates to changes in microstructure. The test series was designed to study three aspects: the intrinsic creep properties of intact, undamaged ice; the enhancement of creep and changes in microstructure due to damage; and the effects of different stress paths. Tests on intact ice with triaxial confining pressures and low deviatoric stresses, aimed at defining the intrinsic creep response in the absence of microcracking, showed that an accelerated creep rate occurred at relatively low deviatoric stresses. Hence, a minimum Creep rate occurred under these conditions. Recrystallization to a smaller grain-size and void formation were observed. Ice damaged uniaxially and triaxially prior to testing showed enhancement of creep under both uniaxial and triaxial loading conditions Creep rates in triaxially damaged ice were found to be non-linear with high deviatoric stresses, corresponding to a power-law dependence of creep rate. Uniaxially damaged specimens contained microcracks parallel to the stressed direction which tended to close under triaxial confinement. Damage under triaxial conditions at low confining pressures produced small recrystallized grains near zones of microcracking. At high confining pressures, a fine-grained recrystallized structure with no apparent cracking was observed uniformly across the specimen. The recrystallization process contributes significantly to the enhanced creep rates found in damaged specimens.

This paper presents a preliminary account of the glaciological observations made by the Antarctic Expedition of the U.S.S.R. Academy of Sciences in Kaiser Wilhelm II Land, Queen Mary Land and Knox Coast in 1956. The topography of the edge of the ice sheet is described, and the ice regime is discussed, particularly in relation to the existence of ice-free areas such as “Bunger’s oasis”.

As polar ice descends from the free surface to depth in a large ice sheet, it undergoes deformations which give rise to the formation and subsequent evolution of a fabric and associated anisotropy. In this paper two orthotropic models of such strain-induced anisotropy are considered. Model A is based on analysis of the microscopic behaviour of an individual ice crystal with transversely isotropic response and assumed uniform stress in a polycrystal. The macroscopic response of the ice aggregate is then derived by applying the concept of an orientation distribution function, and the resulting viscous law relates the strain rate to the stress and three structure tensors. In model B it is assumed that the macroscopic response of ice is determined by the fabric induced entirely by macroscopic deformations, and all microprocesses taking place at the grain level are ignored. A constitutive relation is derived from a general frame-indifferent law for orthotropic materials, and expresses the stress in terms of the strain rate, strain and throe structure tensors. The two models are applied to determine the viscous response of ice to continued uniaxial compression and simple shearing in order to compare the predictions of both theories.

An assessment of snow loads in Switzerland was required for a revision of the building code. Settling curves of snow are used to compute water equivalents of snow if direct measurements are not available. Based on a frequency analysis, relations between the snow load and the altitude are given for various return periods. Problems of regional effects and of converting the snow-cover data to roof loads are outlined.

Only one form of natural ice has been proved to exist at ordinary pressures. The positions of the oxygen atoms are known definitely from X-ray investigation. These form an open-work structure in which each oxygen is surrounded tetrahedrally by four others, the whole system having hexagonal symmetry. The positions of the hydrogen atoms between each pair of oxygens are not known with certainty, perhaps because they may be continually changing. Curious diffuse X-ray patterns, which are related to the temperature of ice, have yet to be explained in detail, but may throw light on the atomic movements. A cubic form of ice may exist at temperatures below −70° C. and under special conditions, and some less symmetrical high pressure forms have also been studied.

Basal ice stratigraphy in coastal ice cliffs at the Law Dome margin has revealed the basal accretion of clean and debris-bearing ice, marine congelation ice and granular marine ice inland of the margin. Co-isotopic analysis of δ18O and δD isotopes together with solute chemistry were applied to determine the modes of accretion and debris entrainment. The marine congelation ice and the granular marine ice were formed from the basal freezing of desalinated sea water and the episodic mixture of basal meltwater and sea water, respectively. Two different debris-entrainment mechanisms were identified. Debris-band ice with debris concentrations of 6.3–33% (by volume) was formed from proglacial raised beach and shallow marine sediment incorporated by an over-riding advance of the margin. Two other debris-bearing ice types, dispersed debris-poor ice with debris concentrations <0.3% (by volume) and laminated debris ice with debris concentrations 0.9–1.9% (by volume) were accreted further inland from the margin by basal regelation processes associated with the Robin (1976) heat-pump effect.

The discharge pattern of the “Schei River”, which drains a 91.2 km2 partly glacierized catchment on Ellesmere Island, is dominated by diurnal oscillations reflecting variations in the melt rate of snow and ice in the basin. Superimposed on this diurnal pattern are numerous short–lived discharge fluctuations of irregular periodicity and magnitude. The characteristics of such irregular fluctuations are described and attributed to periodic collapse of the glacier margin and concomitant damming of the main tributary of the “Schei River”. Collapse is initiated by the river undercutting the ice margin, and tends to be most frequent in the latter part of the flow season during periods of high discharge. Release of ponded water following the collapse of such ice dams may engender significant flood events.

Measurements were made of the kinetic friction which occurs when a tungsten carbide ball slides in various directions on the surface of a single crystal of ice, the track width produced on the surface was also measured. Anisotropies were detected in both the friction coefficient and the track width. The track width φ was at a maximum when the ball was slid normal to the basal plane and a minimum when it was moving parallel to (0001) in the temperature range —5 to —30°C. Although the friction coefficient was at a minimum when slid normal to (0001) and maximum in parallel to (0001) at temperatures of —19°C and below, this relation was found to be reversed at temperatures of —10°C and above. Anisotropy in track width can be explained in terms of the amount by which a slip system contributes to deformation in a specimen. However, our understanding of frictional anisotropy calls for knowledge of the ploughing strength p defined by the adhesion theory of friction. It was found that p reached a maximum in parallel to (0001) and a minimum normal to (0001) and that the frictional anisotropy on (0001) was influenced by the value . A remarkable frictional anisotropy was also observed on the surface inclined to the basal plane at 30°; the maximum friction coefficient was twice the minimum, whereas the maximum track width was only 1.3 times the minimum.

Ice unquestionably exists on Mars. Annual polar-region frost blankets are principally solid CO2, and perennial residual ice caps near each pole are probably water ice, except for a part of the north polar cap which may consist of a 1 km thick mass of solid CO2. Minor amounts of carbon-dioxide clathrate (CO2 · ≈ 6H2O) presumably accompany the solid CO2. The annual frost blankets may have a concentric banding with an outermost very thin layer of water frost, an intermediate narrow zone of clathrate, and a major central core of solid CO2.

Layered deposits and underlying homogeneous materials mantle large areas within both polar regions. These blankets are probably composed of dust, volcanic ash, or both, and possibly contain frozen volatiles. They may comprise the largest reservoir of water substance on the Martian surface.

Ground ice formed by the freezing of ascending de-gassed water substance may underlie the surface of Mars. Localized collapse of small areas may be due to ground-ice deterioration, and recession of steep slopes may have been caused by ground-ice sapping.

If liquid water ever existed in significant quantities on the Martian surface, intense frost shattering, widespread creep, and prolific development of patterned structures should have occurred because the thermal regimen of the surface is highly favorable to the freeze–thaw process. It is ineffective at present owing to the lack of liquid water.

No evidence suggests that the residual ice caps have ever acted like terrestrial glaciers in terms of erosion and deposition. Currently, they are too thin, too cold, and presumably frozen to their substrates. Their most important function is to buffer the atmosphere in terms of its H2O and CO2 content, thereby exerting a modifying influence on the surface environment of the entire planet.

The group of corries on Croaghaun Mountain on Achill Island is described. The existence of these corries and the absence of any extraneous drift from the mountain is taken as evidence that the inland ice of Co. Mayo did not extend far beyond the present coast. The relation of the corries to the local topography is described, and the effect of the topography on the apparent snow line is discussed. The probable snow line of the main glaciation of the west of Ireland is shown to be in the neighbourhood of 1250 ft. O.D. (384 m.) but may have been as low as 1000 ft. O.D. (305 m.) and that of the Late-glacial period in the neighbourhood of 1750 ft. O.D. (533 m.).

The trapping of bubbles of air in polar ice has provided a unique record of past atmospheric composition. However, the interpretation of measured concentrations depends on the statistics of the trapping process. Measurements of trace atmospheric constituents whose concentrations are changing steadily can be interpreted in terms of an “effective age” of the gas which differs from the age of the ice by a delay which corresponds to the mean trapping time. The statistics of bubble trapping can be modelled as a percolation model which is one of a class of models whose transitions are characterized by large critical fluctuations. These critical fluctuations cause an intrinsic sample-to-sample variability in the delay time and thus in the effective age. Monte Carlo simulations using a lattice model of the firn are presented, showing the effect of finite sample size on the age distribution of trapped gas. For samples containing more than about 103–104 bubbles, the simulations indicate that the range of variability is small compared to the average duration of the trapping process.

Palaeo-glacial landforms can give insights into bed roughness that currently cannot be captured underneath contemporary-ice streams. A few studies have measured bed roughness of palaeo-ice streams but the bed roughness of specific landform assemblages has not been assessed. If glacial landform assemblages have a characteristic bed-roughness signature, this could potentially be used to constrain where certain landform assemblages exist underneath contemporary-ice sheets. To test this, bed roughness was calculated along 5 m × 5 m resolution transects (NEXTMap DTM, 5 m resolution), which were placed over glacial landform assemblages (e.g. drumlins) in the UK. We find that a combination of total roughness and anisotropy of roughness can be used to define characteristic roughness signatures of glacial landform assemblages. The results show that different window sizes are required to determine the characteristic roughness for a wide range of landform types and to produce bed-roughness signatures of these. Mega scale glacial lineations on average have the lowest bed-roughness values and are the most anisotropic landform assemblage.

The direction of inland ice movement can, in some cases, be reconstructed by a study of the forms at the base of till strata. These forms are “ribs”, which are formed either as slickensides or as a type of negative “flute”; “edges” and “wedges”, which are caused by shearing movements at the base of the ice; or “undulations”, probably created by restricting movements at the base of the ice. These forms appear to be elongated in the direction of ice movement. As these features can easily be measured, they can be used to check, supplement, or replace the results of till-fabric measurements.

Electrical conductivity profiling allows definition of the hydrology of glacier boreholes occupied by contrasting water types. An inexpensive, robust conductivity profiling system is described that allows detailed description of borehole hydrostratigraphy with reasonable reproducibility. Field dato demonstrate the need to distinguish between bottom water in boreholes and basal water in drainage systems at the glacier bed.

Deep, partly snow-filled gullies cutting the sea cliffs of part of the Vestspitsbergen strandflat are noted. They do not appear to have been cut by streams, and it is suggested that a process of frost action and snowpatch erosion has been largely responsible for their formation.

A short note on glacial recession in part of Vestspitsbergen is added.