Surface Velocities of Glaciers in Western Canada from Speckle-Tracking of ALOS PALSAR and RADARSAT-2 data

ABSTRACT

Speckle-tracking of historically acquired ALOS PALSAR and RADARSAT-2 datasets are used to determine the dynamics of major glaciers and ice masses in western Canada over the past decade. For the icefields of the St. Elias Mountains and those that fringe the northern British Columbia/Alaska border, our results are largely consistent with earlier studies that used the same data, but different speckle-tracking techniques, to derive ice motion. However, our results are generally more spatially comprehensive than those previously published, in particular in fast-flowing regions such as Hubbard, Seward, Tweedsmuir and Lowell glaciers. We also produce new velocity maps for the icefields located in the Coast Mountains of southwestern British Columbia and for the Chaba, Clemenceau and Columbia icefields of the Rocky Mountains. Generally, faster flow is present on large ocean- and land-terminating outlet glaciers, particularly those in high accumulation maritime regions. These results, taken together with velocity maps of the Canadian Arctic and Yukon produced in previous studies, mean that baseline maps of glacier velocities determined from speckle tracking of SAR datasets are now available for nearly all the major ice masses of Canada.

Acknowledgements

We thank the Natural Sciences and Engineering Research Council of Canada (Discovery Grants to LC, MS, and HJ) and University of Ottawa for funding. We thank Parks Canada, in particular Darrell Zell, for providing access to the RADARSAT-2 data used to derive ice motion for the Clemenceau Icefield and Mike Demuth of the Geological Survey of Canada (Natural Resources Canada) for providing access to RADARSAT-2 data for the Columbia Icefield. All ALOS PALSAR data were obtained via the Alaska Satellite Facility's Vertex Data Portal. We thank Alexandra Waechter for insightful comments on an early version of this manuscript, and an anonymous reviewer who helped improve this work.