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ItemNo Preview AvailableContributions to glaciology and polar engineering(University of Melbourne, 1969)
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ItemA study of factors governing the mass economy of Antarctica(University of Melbourne, 1959)The investigations which have gradually revealed to us the nature and workings of the great ice cap of Antarctica were initiated by explorers of the nineteenth century who determined the broad outlines of the continent. At the beginning of the present century the first land-based expeditions enabled scientists to describe the glacial processes and even undertake some measurements. In 1902 Drygalski measured the movement of the glacier ice at Gaussberg, and precipitation measurements were made at Snow Hill Island by Nordenskjold's Swedish expedition in the same year. During Shackleton's expedition of 1907-19 David and Priestley made glaciological observations and during Scott�s last expedition, 1910-13, Wright and Priestley undertook anew and ice studies which led to the publication in 1922 of their classic 1 book on glaciology. Mawson's Australasian Antarctic Expedition, 1911-14, made glaciological studies, and for the first time in Antarctica an attempt was made to measure the amount of snow blown off the ice cap and out to sea. Between the two World Wars there was little scientific investigation of the ice cap, apart from the work done by Byrd's expedition in 1939-41. There was, however, an important step forward when systematic aerial photography was introduced to Antarctica by Lars Christensen in 1936-37 and Ritscher in 1939. After the Second World War, in 1947. Byrd made an intensive survey of a large part of Antarctica and the huge collection of air photographs secured during this operation gave an overall integrated picture of the ice cap and its physical features. In this post-war period the chain of bases first established in 1943-44 by the Falkland Islands Dependencies Survey was extended, but their outlying situation on the Graham Land peninsula was unsuited to studies of the main ice cap. From 1950 to 1952 the Norwegian-British-Swedish Antarctic Expedition worked in Dronning Maud Land. This expedition was of considerable significance, since it established the principle of close international co-operation and also went into the field with a scientific programme already planned in detail with the aid of air photographs. The expedition used mechanical transport with success and mane the first seismic ice depth measurements on the inland ice. The well executed field work has been followed up by the publication of excellent scientific reports. In 1950 Expeditions Polaires Fran�aises set up a base, Port Martin, on the coast of Terre Ad�lie and this base was occupied for two years before being destroyed by fire. The observations mane in Terre Ad�lie provided the material for an important work on glaciology by Loewe (1956), as well as for a number of shorter papers. A small French base was maintained at Pointe Geologie in 1952, but in 1953 France temporarily withdrew from Antarctica. In 1954 the Australian national Antarctic Research Expeditions, under the direction of Mr. P.G.Law, set up a permanent Antarctic base, Mawson, on the coast of MacRobertson Land. During the first year of occupation measurements of accumulation and ablation were initiated by R. Dovers and firn temperatures were measured on the ice cap. In the following two years observations were extended to include measurements of ice movement, the work being carried out by P. Crohn. The International Geophysical Year of 1957-58, a development from the Polar Years of 1882-83 and 1932-33, called for the setting up of many Antarctic bases by different nations (see map 1) and for a detailed study of glaciology. For the first time simultaneous measurements were to be made in many different parts of the continent and improved means of transportation would permit wide areas to be covered by each expedition. In 1956 the author joined the Australian National Research Expeditions as glaciologist and in 1957 wintered at Mawson. Equipment and facilities for glaciological went were limited, but a wide range of topics was studied. The results obtained in the field were analysed in Melbourne in conjunction with the Meteorology Department, Melbourne University, during the austral winter of 1958, and in the summer of 1959 the author was given the opportunity of returning to Antarctica in the m.v. "Magga Dan" to make further studies and to install at Wilkes base equipment developed from experience gained in 1957. Some results have already been published, but in the present thesis the observations which lead to an outline of the mass economy of the ice cap have been brought together. After giving a general account of the nature and behaviour of the ice cap the accumulation of snow on the surface of the ice is described and the transformation of snow into ice is touched upon. Measurements of accumulation from MacRobertson Land are compared with similar ones from other parts of Antarctica and values leading to an accumulation estimate for the whole ice sheet are introduced. The agencies responsible for removal of ice from the continent are then discussed and measurements of ice flow, ablation, and wind-blown snow are given, together with descriptions of the measuring techniques used. A still undetermined factor in the Antarctic mass budget, oceanic melting beneath ice shelves, is briefly discussed. Since the mass budget, towards which the observations lead, is intended to show whether or not the ice cap is in equilibrium at present, direct observations on fluctuations of ice level are given in the chapter dealing with past and contemporary variations in the positions of the ice margins. Finally, mass budgets for the region studied and for the whole of Antarctica are drawn up. The average precipitation over Antarctica is estimated and the ice import and export estimates are compared, showing a large surplus of accumulation over ice loss. This apparent indication of a growing ice cap is regarded with some doubt and it is concluded that more data are needed before this result can be accepted.