Citation

Hugenholtz C, Moorman B, Barlow J, Wainstein P. Landslides 2008; 5(3): 251-260.

Copyright

(Copyright © 2008, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s10346-008-0116-5

PMID

unavailable

Abstract

In this paper the development of a large-scale gravitational deformation involving the eastern lateral moraine of the Athabasca Glacier in Jasper National Park, Alberta, Canada, is described. Interpretation and analysis of sequential aerial photographs indicates that a 540-m-wide segment of the eastern lateral moraine began to deform in the early 1950s; however, significant movement only began in the late 1960s. Since then, the moraine has undergone progressive gravitational deformation leading to a network of fractures, bulging, and the development of a large gap in the moraine crest. Geographic information system analysis of topographic changes between 1967 and 2006 indicates that the displaced volume of the moraine is approximately 9.0 × 10 5 m 3 . In the last 39 years, the moraine crest has displaced 55 m (1.4 m yr −1 ) down towards the glacier. The development of slope instability is linked to a combination of debuttressing from recent glacier recession, deformation of the moraine, as well as the movement of a large, mobile, debris-mantled slope impinging the upslope margin of the lateral moraine. This case study illustrates the importance of glacial conditioning and local geomorphological factors in creating conditions for large-scale moraine instability in recently deglacierized alpine basins.