Preliminary Data from Saskatchewan Glacier, Alberta, Canada

An understanding of glacier flow is not likely to come from field or laboratory studies alone; both are required. Needed from the field are quantitative data on the movement, size, shape, slope, and thickness of flowing ice bodies. Reliable measurements of the amount and absolute direction of movement at points widely distributed over the surfaces of glaciers are sparse. Even the surface velocity map of Hintereisferner (Hess, 1904, p. 136), one of our most thoroughly studied ice streams, shows only the downvalley component of movement. Quantitative data on velocity distribution in depth are even more meagre (Gerrard, Perutz and Roch, 1952; Sharp, 1953), although they are essential to an understanding of the physical properties and behaviour of ice deep within a glacier and to the setting up and interpretation of laboratory experiments. Thickness is known in reasonable detail for a few European valley glaciers (Hess, 1933, p. 43; Renaud and Mercanton, 1948) and along one profile in the Greenland Ice Sheet (Joset, 1950, p. 54), but it has been determined only locally in North American ice bodies (Goldthwait, 1936, pp. 506-7; Poulter, Allen, and Miller, 1949; Littlewood, 1952, p. 124; Allen and Smith, 1953, p. 758; Rothlisberger, 1953, pp. 234-7)