In 1900 Sperry Glacier had an area of 3.39 km2. By 1938 it had
diminished to 1.58 km2 and by 1946 it was only 1.34 km2 in area.
The estimated loss in volume between 1938 and 1946 was a 23
meter reduction in the level of the surface of the lower half of
the glacier during that period. Recession proceeded at an annual
rate of 15.3 m. be¬tween 1938 and 1945; 11.9 m. from 1945 to
1947; 10.5 m. from 1947 to 1948; and 12.9 m. from 1948 to 1949
(Dyson, 1950). Recession of Sperry Glacier continued from about
1950-1970 and has been accompanied by loss of volume of the
lower part of the glacier. Sperry Glacier has been examined in
reconnaissance (Johnson, 1958, 1960, 1964). Comparison of
longitudinal and transverse profiles shows that since 1947 the
upper part of the glacier has increased in vol¬ume during some
years and remained constant during others, whereas the lower
part has decreased in volume. Throughout this time span slow
terminal recession has been continuous. Surface ice velocities
on Sperry Glacier average