Antarctic Glacial and Subglacial Topography

1. The data is collected and generalized according to 48,000km of surface traverses in Antarctica during the last 15 years. An evaluation is made of reliability of material and methods of study of the ice cover thickness, evaluation of precision of levelling methods and prospects of aeromagnetic, radar and electrical methods for the study of the ice cover thickness of Antarctica. Methods are suggested which allow to make indirect evaluation of the relief of the subglacial bed of Antarctica according to the relief and inclination of the sufrace, crevassing of the ice cover and geological structures. 2. By application of the material on subglacial bed relief YU.N. AVSYUK, L.I. IVASHUTINA, A.P. KAPITZA and O.G. SOROKHTIN compiled the map of subglacial bed relief of Antarctica. The horizontal contours are drawn every 500m. In the process of Antarctic researches new large forms of sub-ice relief were revealed : Gamburtsev Mts., Vernadsky Mts., Golitsin Mts., Shchukin Mts., Schmidt Plateau, East Plateau, West Plateau. In the process of generalization of materials large faults were found in Antarctica : the Trans-Antarctic trough. 3. The map of the thickness of ice cover in Antarctica has been made by the method of graphical subtraction by using the map of subglacial relief of Antarctica and the map of ice cover surface. The amount of ice in Antarctica was estimated according to that map, which makes 24 million km^3 of ice. 4. On the basis of the analysis of the map of ice cover surface a map has been compiled of the lines of ice flow, and the main ice divides and centers of ice diffluence in Antarctica were determined. 5. Geophysical data testify that the earth\u27s crust in Antarctica is in the state of isostatic equilibrium, while at the same time separate forms of the relief have deviations of mean values of the free air anomaly, which allow to propose a hypothesis about the general reduction of the ice cover of Antarctica in the Holocene. The general retreat of glaciers does not contradict the separate data about shortperiod (within tens or hundreds of years) advances of ice cover edge. 7. The analysis of data about the subglacial relief of Antarctica has been used in calculation of the uprising values of the earth\u27s crust after deglaciation, and a map is compiled predicting contours of the continent in the Post-Glacial Period with compensational uprising. 8. Major trends are suggested of the study of subglacial bed of Antarctica and of the ice cover relief for the solution of the most important glaciological and geomorphological problems of Antarctica