This report is intended to summarize activities in radio echo sounding since the introductory paper which appeared in the Polar Record four years ago (Evans, 1963 a). The field work since that time is discussed in rough chronological order, with references to the sources of more detailed information and an assessment of the principal results.

The Arctic Research Laboratory (ARL) is a year-round, continuing, basic research facility, funded by the Office of Naval Research (ONR), US Department of Navy, and located in lat 71° 21'N, long 156° 46'W, near Point Barrow, on the Arctic coast of Alaska. It was established in 1947 not, as could be reasonably expected, only to further investigations of immediate and practical use to the Navy, but also to support work of purely general scientific interest. Scientists from other countries were also invited to make use of its facilities. ARL represents a laudable co-operation between government support and private scientific enterprise.

The cause of the phenomenally high winds recorded by Sir Douglas Mawson's party at Cape Denison during the Australasian Antarctic Expedition, 1911–14 (Mawson, 1939), and by the French expedition to Port Martin in 1950–51 (Boujon, 1954) has never been satisfactorily explained. As indicated in the Table, the annual mean wind recorded at those stations, 71·1 and 64·6 km per h respectively, is about 70 per cent greater than recorded elsewhere around the coast at stations fully exposed to katabatic flow, notably Mirny and Mawson. Admittedly, the total number of coastal stations is small, considering the length of the Antarctic coastline, and one cannot exclude the possibility that similar very strong winds prevail in other places. Nevertheless, the figures for Cape Denison and Port Martin are notable, if not unique, and the question arises why this should occur on the coast of Terre Adélie.

Hovercraft, or air-cushion vehicles, have been proposed several times as a means of polar transport (Mellor, 1963; Fuchs, 1964, 1966; Law, 1965; Cooper, 1965). They ride on a cushion of low pressure air which eliminates friction between the craft and the ground surface, the air being contained by flexible skirts and peripheral jets to give a substantial obstacle clearance. Their low bearing pressure (of the order of 0·01 kg/cm2) makes them potentially suitable for over-snow use. They can travel equally well over ice, snow, and water and thus can give year-round service on Arctic rivers and seas. There is no need for costly facilities such as docks or airstrips at terminals. Finally, the hard structure clearance provided by the flexible skirts should enable the vehicle to cross areas of rough sea ice or pressure ridges without a route being prepared.

The Lambert Glacier system, one of the largest in Antarctica, drains from Princess Elizabeth Land into Prydz Bay, terminating in the Amery Ice Shelf, in about long 70° to 75° E.

South Georgia has been the site of a controlled commercial sealing industry since 1909. The Southern Elephant Seal (Mirounga leonina) is killed for the oil obtained from the processing of the skin and subcutaneous fat, in a manner similar to the processing of whale blubber.

The island is divided into four sealing divisions, each with an annual catch quota which is subject to revision if necessary at the completion of each season, depending on information obtained from the average age of the catch, and an annual population census. There are also reserve areas, in which commercial killing is prohibited and which provide controls for comparison between commercially exploited herds and those which are undisturbed. The latter begin to breed an earlier age, reach their peak breeding period earlier and bear a smaller ratio of cow to bull calves than the former. The total kill permissible over the last decade has remained at 6000 adult bull seals over 3·5 m in length. At present, the catch quotas in each division are as follows:

In 1949 the Australian National Antarctic Research Expeditions (ANARE) began a long-term ecological study of the Southern Elephant Seal (Mirounga leonina) at HeardIsland. The biologists devised a method of branding seals for individual recognition (Chittleborough and Ealey, 1953) which has been modified only in detail since then (Carrick and Ingham, 1962a). At Heard Island, pups were branded every year until 1953, but the study here came to an end with the closing of the ANARE station in 1955. At Macquarie Island, pups have been branded every year from 1951 to 1965, giving a sample of individuals of known age and known history.