Recent volume loss of British Columbian glaciers, Canada

We use the Shuttle Radar Topography Mission ( SRTM) data and digital terrain models from aerial photography to quantify the change of glacier volume in British Columbia ( BC), Canada for the period 1985 - 1999. We note substantial elevation bias in the SRTM elevations, typically on the order of - 12 m km(-1). The bias- corrected thinning rate is -0.78 +/- 0.19 m a(-1) which yields an annual volume loss of 22.48 +/- 5.53 km(-3) a(-1). This rate of glacier volume loss is 65% of the estimate uncorrected for elevation bias (34.7 km(-3) a(-1)) and cautions against the use of uncorrected SRTM data for glacier change studies. Glacier recession in BC could account for ca. 0.67 +/- 0.12 mm of sea level rise over the period 1985 - 1999 (0.05 +/- 0.009 mm yr(-1)) or about 8.3% of the contribution from mountain glaciers and ice caps. The recent rate of glacier loss in the Coast Mountains ( 17.0 km(-3) a(-1)) is approximately double that observed for the previous two decades.