Glacier Volumes

Glacier volume measurements require a labour and capital-intensive approach. Volume-Area (V-A) and other scaling relations have been derived from the available global ice-thickness data. Based on empirical volume data from 63 glaciers around the world (seismic and radar), Chen and Ohmura (1990) derived the following curvilinear relationship between glacier area and volume:

V = cA^b

where V (106 m³) is the volume and A (km²) is the surface area of the glacier. In their analysis they found c to be 28.5 and b to be 1.357. As the data used to derive these constants is from many different regions, the values for c and b can be considered a sort of world average and c, in particular, needs to be adjusted regionally. To give an idea of the regional variability in c, Chen and Ohmura found a value of 16.1 in the Alps and 48.0 in Svalbard. However, individual glaciers can deviate dramatically from the above formula / relationship as a result of complex or deeply eroded bed topography, unusual ice flow regimes (extensive glacier sliding), or as a result of being far out of equilibrium.

Glacier thickness data is available from six sites in the Rocky Mountains: the Grinnell (Montana), Dinwoody (Wyoming), Haig, Rae, Peyto, and Athabasca Glaciers. The latter four are in Alberta. Glacier volumes are estimated to be 55km³ (± 15km³) for all of the glaciers in the eastern slopes, with 47km³ (± 15km³) in Alberta and the remainder in the eastward-draining ice masses of the Peace River Basin in B.C.

The table below provides glacier area and volume estimates for Alberta river basins, based on the WC²N glacier inventory for 2005. Best estimates are based on the mean prediction from the four volume estimation methods, and modelled values.