TV-video observations of bed and basal sliding on Storglaciären, Sweden

Abstract Four boreholes in Storglaciären, a small valley glacier in northern Sweden, were inspected with a video camera. In two of the boreholes, the apparent glacier bed was filmed. In one borehole, the bed was found to be composed of soft sediment, but in the other it consisted of bedrock. In the...

Full description

Bibliographic Details
Published in:Journal of Glaciology
Main Author: Pohjola, Veijo Allan
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1993
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000015768
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015768
Description
Summary:Abstract Four boreholes in Storglaciären, a small valley glacier in northern Sweden, were inspected with a video camera. In two of the boreholes, the apparent glacier bed was filmed. In one borehole, the bed was found to be composed of soft sediment, but in the other it consisted of bedrock. In the latter, the camera moved 5.6 mm relative to the bed during an 80 min period. The recorded camera movement showed a background motion which is in the expected range of basal sliding. Superimposed on the background motion, a jerky motion of a high-speed spike was found. The jerky motion is interpreted as a stress release induced by local topography at the ice–bed interface.