A 10 m deep core and a 2 m pit were achieved in December 1977 on the ice cap of James Ross Island (Antarctic Peninsula) 3 km westward of the main dome at an altitude of 1 500 m. The 10 m temperature was −14.2°C. The core was cut into 106 samples which have been used for density, total β radioactivity, electroconductivity, and deuterium-content measurements. The age at the bottom of the bore hole has been estimated to be 1 965±1 year and a mean annual snow accumulation rate 37.7±3.0 g cm−2 a−1 is calculated over the last 13 years. By comparing our results with those obtained in other areas of the Peninsula, the climate of the upper part of James Ross Island seems to follow the climatic regime of the western coast. A preliminary chemical analysis of the pit samples leads us to conclude that the snow impurities are mainly sea-salt derived. The conductivity measurements show a clearly defined peak at the end of 1967 which could be linked with the volcanic eruption of the Deception Island volcano in December 1967. The interest of the studied location is discussed in view of further more extended glaciological investigations and particularly a possible coring to the bottom.

The paper tries to reconcile the facts that there are often useful correlations between ablation or run-off and air temperature while net radiation is usually the major source of ablation energy. Equations are derived from the energy balance to describe statistics for the ablation-temperature relation in terms of statistics for the relations between individual energy fluxes and air temperature. As examples, statistics are evaluated for four published series from Arctic Canada. Although the net radiation is the largest energy source in all four cases, the ablation rate is moderately well correlated with temperature and poorly correlated with net radiation. This is because the sensible heat flux is more variable than the radiation in three cases and is itself better correlated with temperature in all four cases. The major contributions to the increase of ablation rate with temperature (on average 6.3 kg m−2 d−1 deg−1) are due to sensible heat, followed by latent heat with a small contribution from net radiation. The resulting ablation-temperature model explains about half the variance of ablation rate. The main application of such a simple model is for the estimation of ablation totals in areas where glaciological and hydrological data are sparse.

Frequently the reservoir region of a cold surge-type glacier has a temperate base, while in a region surrounding the reservoir the base is cold. We analyse the slump process in such a reservoir region— that is, the process whereby material flows toward the lower end of the region and forms a critical wave profile there. The model agrees qualitatively with observations of Trapridge Glacier, Yukon Territory, Canada, which is currently experiencing a critical pre-surge condition. Calculations based on the model give good agreement with the surge cycle time of Rusty Glacier, Yukon Territory. Laboratory experiments show that a large-amplitude slump-induced wave profile forms prior to a surge. Experimental surges were produced with velocity increases of order one hundred.

In order to interpret observed short-term variations of the sliding velocity of a glacier the effect of a variable subglacial water pressure on the sliding velocity has been studied using an idealized numerical model. In particular the transient stages of growing or shrinking water-filled cavities at the ice-bedrock interface were analysed. It was found that the sliding velocity was larger when cavities were growing than when they had reached the steady-state size for a given water pressure. The smallest sliding velocities occurred while cavities were shrinking. When cavitation is substantial a small drop of water pressure below the steady-state value (e.g. by 0.5 bar) can temporarily cause backward sliding. A limiting water pressure at which sliding becomes unstable is derived. The consequences of more realistic assumptions than those of the model are discussed.

During the June-July 1979 expedition a large variety of micro-forms was observed at the surface of the Quelccaya ice cap, their altitudinal distribution being primarily controlled by the heat budget. At 5200–5300 m penitentes are best developed, with azimuth orientation and inclination of features conforming to the insolation geometry around local noon. At a westward-facing slope in 5360–5380 m a set of penitentes striking parallel to the contours is superimposed on the pattern dominating at the lower elevations. The ablation forms of penitentes give way to various deposition features above a transition zone around 5400 m in broad agreement with the larger net all-wave radiation and greater importance of melting at lower elevations. The succession of forms with an upward change from surface-parallel plates to elaborate dendritic forms appears to be controlled by the temperature conditions. The conspicuous development of forms encountered during the 1979 expedition appears characteristic of prolonged absence of fresh snow-fall subsequent to a season with abundant precipitation.

Bottom melting rates have been calculated for a large number of sites on George VI Ice Shelf from measurements of its kinematic behaviour. No simple explanation for the melt-rate pattern was found in terms of ice-shelf parameters, assuming steady-state conditions. Values of apparent melt rates varied from 1 to 8 m a−1 of ice. Along different flow lines the melt rate would sometimes increase with distance from the grounding line and sometimes the melt rate would decrease with distance. Large melt rates were found both where ice flowed off Palmer Land and where the ice shelf butted against Alexander Island. Although oceanographic conditions probably control bottom melting rates the complex pattern with large spatial variation seems to indicate that some areas of ice shelf are changing in thickness.

A regression model calibrated on 23 cirques from the Sangre de Cristo Mountains, south-central Colorado, suggests that local-scale climatic controls interact with geologic materials to explain intramountain variation to cirque development. Topoclimatic effects maximize cirque development on ridges that project well above the Pleistocene glaciation limit, and in positions that minimize total radiation receipt. If an optimum topoclimate coincides with densely jointed (erosible) bedrock materials, cirque development will be at a maximum. However, cirque development can be deceptively poor in situations where a favorable topoclimate coincides with massive (sparsely jointed) bedrock materials. The interaction between local-scale climatic–geologic controls subsumes their independent effects. Significant correlation between cirque development and an individual process control may not emerge due to complications produced by one or more other controls.

Equipment has been designed and tested for ground-based and airborne sounding of temperate glaciers. The transmitter is a free-running pulse generator that uses avalanche-mode transistor breakdown to create high-voltage pulses. The transmit and receive antennas are resistively loaded dipoles; for the airborne system, a twin-lead transmit element and a three-layer coaxial receive element are used on the inboard end of the respective antennas. The sounders are broadband systems; oscilloscopes are used for receivers. The oscilloscope trace is recorded photographically in the ground-based systems. A sampling oscilloscope is used in the airborne system—the sampling process strobes the waveform to audio frequencies so that it can be recorded on magnetic tape. Echoes have been obtained from ice depths of 550 m using the airborne system and about 1 000 m using the ground-based system.

An electromagnetic stress-wave generator which was developed to study shock waves in snow and ice is described. This system works on the principle of generating large electrical currents to produce highly transient loads on the test specimen. In its present configuration, the generator can produce pressures ranging from a few kilopascals to as large as 104 kPa and load frequencies as, high as 150 kHz. The system has been found to have high repeatability and has good turn-round time.

The design and operating characteristics are presented for a visible and near-infrared scanning photometer which can measure incident and reflected spectral irradiance from 400 nm to 2 450 nm. The instrument is designed to record over 98% of the solar radiation incident upon and reflected from the Earth’s surface using a turret-type cosine collector and a circular variable interference filter. The apparatus has been tested successfully on Arctic sea ice at temperatures down to –20°C. It is self-contained and easily portable, and its mass is less than 16 kg. Some preliminary results are presented.

A layer of moraine within the Antarctic ice sheet has been detected in the course of airborne radar ice soundings. The moraine was injected at the margin of the ice and can serve as a tracer to pick out a particle path within the ice. When combined with surface measurements, the ability to trace particle paths should allow detailed modelling of the dynamic behaviour in limited areas.

The Orville Coast area of the Antarctic Peninsula was extensively glacierized in the past. Striations, polished rock surfaces, and erratics on nunatak summits indicate that this area was covered by a broad regional ice sheet whose grounded ice margin was on the continental shelf, in the present-day Ronne Ice Shelf area. If the glacial history of Antarctica has been controlled by eustatic sea-level changes, the destruction of this ice sheet would have been contemporaneous with that of the Ross Sea ice sheet due to the world-wide rise of eustatic sea-level at the end of the Wisconsin glaciation.

Some features around the perimeter of the Balgesvarri plateau ice cap are described. Sorted stone circles were found beneath a slowly retreating ice margin, the basal ice in this area appears to be below the pressure-melting point. No absolute dating of features was possible but a relative chronology is suggested.

Drumlin till has often been described as clay-rich. Drumlins in Ontario are composed of sandy till. Additional examples from north-eastern North America show that sandy till is common in drumlins.

It is suggested that the widely accepted association between drumlins and clay till was fostered by the use of such terms as “boulder clay” and “glacial clay”. Also, because till in drumlins may be finer than other glacial materials in such areas as the Appalachian region, a loose and exaggerated description of such material as being clay-rich arose. More careful description of drumlin till is advocated. It is suggested that grain-size distribution of till may have had a role in drumlin formation.

Recent investigations have shown that various factors may affect the shear strength of glacial till and that these factors may be involved in the drumlin-forming process. The presence of frozen till in the deforming zone, variation in pore-water pressure in the till, and the occurrence of random patches of dense stony-till texture have been considered. The occurrence of dense stony till may relate to the dilatancy hypothesis and can be considered a likely drumlin-forming factor within the region of critical stress levels. The up-glacier stress level now appears to be the more important, and to provide a sharper division between drumlin-forming and non-drumlin-forming conditions.

In order to flow with the gradients observed (10° to 15°) rock glaciers cannot be simply ice-cemented rock debris, but probably contain masses or lenses of debris-free ice. The nature and origin of the ice in rock glaciers that are in no way connected to ice glaciers has not been adequately explained. Rock glaciers and talus above them are permeable. Water from snow-melt and rain flows through the lower part of the debris on top of the bedrock floor. In the headward part of a rock glacier, where the total thickness is not great, if this groundwater flow is able to maintain water pressure against the base of an aggrading permafrost, segregation of ice lenses should take place. Ice segregation on a large scale would produce lenses of clear ice of sufficient size to permit the streams or lobes of rock debris to flow with gradients comparable to those of glaciers. It would also account for the substantial loss in volume that takes place when a rock glacier stabilizes and collapses.

Recession of “Golden Eagle” glacier in the central Brooks Range is exposing undisturbed lichen-covered boulders. Radiocarbon analysis of dead moss surrounding these boulders dates a Neoglacial advance across this site at 1120±180 years b.p Measurements of the preserved lichens indicate that a minimum ice-free period of 1500–2500 years preceded this glacial expansion.