Annual record of glacier terminus response to climate variability over the period 1959-2004 derived from annual push moraines, Castle Glacier, British Columbia

Few studies examine glacier change in the Cariboo Mountains of British Columbia. During the past half century a rarely preserved sequence of push moraines was formed at the front of one of these glaciers (informally named Castle Glacier, 53° 1’ 52” N., 120° 27’ 44” W.). We used aerial photography and satellite imagery to confirm this sequence of deposits to be annual and to derive an annual record of glacier retreat. Castle Glacier formed 46 annual push moraines and retreated 671 m between 1959 and 2004. Average annual retreat during this period was 14.6 m a-1 and varied between 3 and 44 m a-1. Minimum annual retreat occurred in the 1970s and maximum annual retreat occurred in the early 1990s. Comparison of meteorological data obtained from nearby climate stations with those of annual glacier retreat indicates that Castle Glacier terminus response correlates most strongly with ablation season temperature (r = 0.53, á = 0.01)