The evidence for the existence of small glaciers in the cwms of the Caernarvonshire mountains during the Late-glacial Period is presented, and by an analysis of their distribution some of the factors responsible for their formation are deduced. These were primarily protection from insolation, drifting of snow into the cirques by wind and the distribution of precipitation.

Motion produced by ice expansion and by wind-blown ice cakes has modified the shores of lakes in northern New England, U.S.A. Twenty-six lakes have been studied, the processes observed, and measurements made of the rate and extent of ice action. Conclusions as to the effectiveness of the two processes are brought out.

Recent investigations of the ice of the central polar basin have been largely done by Russians, and some of their results are given here. General characteristics of the ice and of the currents and bathymetry of the area are outlined. Attention is directed to advances in knowledge in two spheres; the effect of currents and local winds on ice drift, and the growth and structure of floes. To illustrate the latter, an explanation of the stratification of a 3 m. vertical section is quoted. In conclusion, the prospects of the work continuing, and of its results being made available, are assessed.

Pleistocene glaciation in the Commonwealth of Australia is confined to Tasmania and a small area on the mainland, chiefly in the Kosciusko plateau of New South Wales. Three glacial stages of decreasing intensity have been recognized—the Malannan, Yolande and Margaret Stages. These are characterized by ice cap, valley glacier and cirque conditions respectively. At its maximum the ice cover extended down to sea-level in western and southern Tasmania, but in New South Wales traces are not known below 1448 m. From consideration of snow line etc. it is estimated that during the maximum glaciation the temperature was about 13° F. (7.2° C.) lower than it is to-day.

A group of previously unmapped glaciers on the slopes of Trident and Katmai Volcanoes, southwestern Alaska, was studied for information on the abnormal regimen produced by effects of the 1912 eruption of Mount Katmai. During the eruption an area of 5 square miles (13 km.2) of the summit above regional snow line was destroyed, and the beheaded glaciers were buried under a blanket of pumice and ash. Field data are presented to indicate that the terminus of Fourth Glacier has been essentially stationary since the 1912 eruption. Upper portions of the glacier have thinned, exposing the rim of the caldera which 40 years ago was partly ringed with fringing ice cliffs. Permafrost has developed to within a few feet of the surface of the pumice mantle. Under prevailing climatic conditions Fourth Glacier may be preserved in its present static condition for an indefinite period.

The Yakataga Glacier occupies a steep-walled valley in the Robinson Mountains on the north coast of the Gulf of Alaska. The main trunk of the glacier descends from 1130 to 150 m. in a distance of 21 km. A rock fall at the head of the glacier formed a moraine of distinctive shape which advanced at an average rate of 114 m./yr. from 1938 to 1954. The surface velocity of the glacier at fifteen stations below the firn line was calculated from the displacement of the rock-fall moraine and other less conspicuous features that are shown in two sets of vertical aerial photographs, taken in 1948 and 1954. For this time interval the average surface velocity along the medial line of the glacier ranged from a maximum of about 90 m./yr. at a station 14 km. above the terminus to zero at a station 2.3 km. above the terminus. The technique of photogrammetric measurement of surface velocity by using natural features on the surface of a glacier has wide application in Alaska, where many glaciers have been rephotographed from the air after intervals of a few years to as many as thirty years.

Separated etch pits can be produced by a simple operation using a plastic replica film. Combining this etching technique with Schaefer’s replica method, it is possible to record both the size distribution and the orientation of crystal axes of individual grains of ice.

Winter conditions on the Mackenzie River and Delta in North-west Canada are discussed. Daily observations during the break-up period of the Mackenzie River for 1954 are recorded, as well as a general record of the break-up of ice in the delta and detailed observations of the break-up in one of the main channels.

Near the edge of Langjökull ice cap there are many soil polygons. A cross-section showed them to be only surface features consisting of rocks in polygonal form embedded in silt. The area revealed much evidence that silt and small rocks often behaved like a liquid upon which heavier rocks would float. If the floating heavier rocks were pushed down into the “liquid,” mud would, in certain circumstances, ooze up a metre or so away. If a number of rocks were depressed the mud would ooze at points roughly equidistant from a few of the rocks, and spread to leave a polygon pattern. Conditions favourable for the sinking of heavy stones in this manner probably occur each spring.