andT. H. Jacka (Antarctic Division, Kingston, Tasmania 71 50, Australia) ABSTRACTThe major results from a comprehensive study of the Amery Ice Shelf are presented, following the work of a wintering expedition in 1968 and supplemented by f u r t h e r measurements during the summer seasons of 1969 to 1971. The programme included ice-core d r i l li n g , oversnow surveys f o r ice movement and optical l e v e l l i n g , ice-thickness sounding, and measurements of snow accumulation. The new data obtained provide the basis f o r a more accurate assessment of the mass balance and dynamics of the ice shelf than was possi b l e from the e a r l i e r surveys.The results indicate a substantial growth of basal ice under the ice shelf inland where the ice thickness is greater than 450 m. Further towards the ice f r o n t the high s t r a i n thinning i s approximately balanced by the horizontal ice advection.The v e l o c i t y d i s t r i b u t i o n over the ice shelf i s primarily governed by a substantial surface slope towards the ice f r o n t and high r e s t r a i n i n g shear stress along the sides.

andT. H. Jacka (Antarctic Division, Kingston, Tasmania 71 50, Australia) ABSTRACTThe major results from a comprehensive study of the Amery Ice Shelf are presented, following the work of a wintering expedition in 1968 and supplemented by f u r t h e r measurements during the summer seasons of 1969 to 1971. The programme included ice-core d r i l li n g , oversnow surveys f o r ice movement and optical l e v e l l i n g , ice-thickness sounding, and measurements of snow accumulation. The new data obtained provide the basis f o r a more accurate assessment of the mass balance and dynamics of the ice shelf than was possi b l e from the e a r l i e r surveys.The results indicate a substantial growth of basal ice under the ice shelf inland where the ice thickness is greater than 450 m. Further towards the ice f r o n t the high s t r a i n thinning i s approximately balanced by the horizontal ice advection.The v e l o c i t y d i s t r i b u t i o n over the ice shelf i s primarily governed by a substantial surface slope towards the ice f r o n t and high r e s t r a i n i n g shear stress along the sides.