Some recent work by Dr. J. F. Nye on the calculation of the thickness of ice sheets has prompted the author to apply Nye’s formula to the Barnes Ice Cap in Baffin Island. A gravimetric survey of the southern lobe was carried out in 1950, and the data from four of the traverses have been used to calculate the variation of the shear stress on the bed. Some of the values obtained are exceptionally low, possibly explained by the fact that the lines of travel over the surface do not necessarily correspond to the lines of greatest slope or lines of flow. Only in one direction are the values relatively high, and it is concluded that there is a considerably greater movement of the ice in this direction. This conclusion is in agreement with observations on the ground.

The wave of cold temperature, which begins to propagate into a snow field during the winter, may be considerably enhanced by the thermal blanketing of snow accumulating on the surface. This effect is discussed theoretically by means of calculations based on the mathematical theory of the conduction of heat in solids. The results of these calculations show that for an assumed steady velocity of accumulation at the rate of 4 meters/year or 8 meters/year, the winter cold wave should assume significantly larger proportions than in the absence of accumulation.

The Fitz Roy district, on the margin of the Patagonian ice field (“Hielo continental”), is subject to continual and very strong west winds of high humidity. Glaciers descend to a very low level. Ablation by rain plays an important part, and contributes to some surface features, such as thin vertical sheets of ice, hummocks and dirt cones (a new theory of the origin of which is given). The summits of aiguilles, always covered with glazed frost in the Fitz Roy area, are incrusted with very heavy deposits of rime in the Cerro Torre and especially in the Cerro Grande areas. This forms huge comices and “feathered snow” to leeward.

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.).

Grfmsvötn (The Lakes of Grünur) is the name of a volcanic centre in Vatnajökull, the eruptions of which accompany the gigantic glacier bursts on Skeidarársandur which occur normally about every tenth year. Recent expeditions to Grimsvötn and reconnoitring flights have led to the view that between glacier bursts the Grlmsvötn depression is gradually filled with water, forming a lake with a maximum area of about 35–40 sq. km. This accumulation of water is partly due to ablation and partly to continuous solfatara and fumarolic activity.

The close resemblance between the discharge graphs of glacier bursts from Grimsvötn and graphs of drainage of normal ice-dammed lakes such as Lake Graenalón is stressed. It is also pointed out that ten years’ accumulation, about 7 cu. km., in the area drained into the Grfmsvötn depression, corresponds roughly with the total discharge of a normal glacier burst from Grfmavötn. It is suggested that the glacier bursts determine the moment of eruption and not vice versa. This might explain the usually very regular intervals between these eruptions. The irregularities occurring since 1934 might be due to the present climatic amelioration.

Three valley glaciers of the eastern Alaska Range are described. On one of these, the Castner Glacier, an unusual medial moraine was discovered, which has its beginning from an outcrop in the center of a cirque-like basin. This large moraine extends down the glacier for 4 miles (6.4 km.) and ends abruptly several miles from the end of the glacier. The advances and recessional behavior as deduced from end moraines, lateral moraines and the limits of forest destruction (forest trimlines) are briefly discussed.

Dirt cones develop where debris has been blown on to snow and has become concentrated into numerous small patches thick enough to protect the underlying snow from ablation. These striking accumulations of dirt, separated by virtually dirt-free snow, are produced by movement (both contraction and expansion) of the snow surface during ablation. Factors controlling this movement operate in such a way that local concentrations of dirt will be produced even when initial deposition of the dirt is almost uniform. The significance of these processes in relation to the development and structure of dirt cone fields is discussed, and certain experiments and observations on dirt cones are described.