Glacier change of the Columbia Icefield, Canadian Rocky Mountains, 1919-2009

Abstract

We determined length, area, elevation and volume change of the Columbia Icefield using Interprovincial Boundary Commission Survey maps from 1919, eight sets of aerial photographs from 1948 to 1993, and satellite data from 1999 to 2009. Over the period 1919-2009, glaciers on average retreated 1150±34m and shrank by 2.4 ±0.2 km2. Total area loss was 59.6 ±1.2 km2 (23 ±5%), and mean elevation change was -49 ± 25 m w.e., resulting in a total volume loss of 14.3 ±2.0 km 3 w.e. Large outlet glaciers experienced the greatest absolute ice loss, while small, detached glaciers lost the most relative length and area. Thinning rates of debris-covered ice were 30-60% lower than those for clean ice. All glacier changes were significantly correlated with each other (p < 0.01), with rvalues ranging from 0.54 to 0.82. Temperature is correlated with length and area change over periods lagged 1-5 years (p<0.05), and with elevation and volume change over periods lagged 9-18 years (p<0.05). Precipitation is correlated with glacier change over periods lagged 1-10 years (p<0.05).