Tasman Glacier Ice Loss Measured

Press, Volume CIII, Issue 30634, 28 December 1964, Page 12

Tasman Glacier Ice Loss Measured

The ice lost by the Tasman Glacier between 1890 and 1962 would have continuously fed a 51-cusec stream, a “not insignificant fraction” of the flow of the lower Tasman river, says Mr B. E. Skinner, of the Geological Survey, Department of Scientific and Industrial Research, in the “New Zealand Journal of Geology and Geophysics.” Mr Skinner compared measurements taken in 1890 by T. N. Brodrick with measurements from the same or similar base-lines in 1962. The average fall in the level of the glacier over that period from the Malte Brun hut to the terminal face was 82.1 metres (268 ft and the volume of ice lost from this region was 3335 million cubic metres (about threefifths of a cubic mile). Brodrick, later surveyorgeneral and under-secretary for lands, was district surveyor for South Canterbury at the time of his Tasman survey.

Brodrick made traverses across the glacier in several places with the primary object of measuring the speed of flow of the glacier. In doing so, he also recorded icelevel. Mr Skinner took two of Brodrick’s traverses —one by the Ball Hut and another just above the Murchison confluence—and attempted to repeat them. Although one of the original stations had been carried away through undercutting, and a mistake was made in the identification of another, the lines established by Mr Skinner were

close enough to Brodrick’s for satisfactory measurements to be made. Photographs published by A. R. Harper in 1934 indicated an appreciable part of tbe loss of volume of the glac er between 1890 and 19CJ occurred in the first half <>f the period, says Mr Skinner.