High-speed video analysis of fracture propagation in a thick edge-loaded freshwater ice sheet

High-speed video (1000 frames/s) was used to record the propagation of fractures in a 1.7 m thick freshwater ice sheet in Tuktoyaktuk Harbor, N.W.T. The fractures were induced by an indentor operating in a 0.33 m deep trench in the ice where it pushed against the upper 0.2 m edge of the sheet. Most...

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Bibliographic Details
Published in:Canadian Journal of Physics
Main Author: Gagnon, R. E.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2003
Subjects:
Online Access:https://doi.org/10.1139/P02-134
https://nrc-publications.canada.ca/eng/view/object/?id=5368bb97-92d7-4167-a4c9-f900793a5f30
https://nrc-publications.canada.ca/fra/voir/objet/?id=5368bb97-92d7-4167-a4c9-f900793a5f30
Description
Summary:High-speed video (1000 frames/s) was used to record the propagation of fractures in a 1.7 m thick freshwater ice sheet in Tuktoyaktuk Harbor, N.W.T. The fractures were induced by an indentor operating in a 0.33 m deep trench in the ice where it pushed against the upper 0.2 m edge of the sheet. Most fractures were planar horizontal shear cracks. Some vertically-oriented horizontally-propagating fractures were also observed. Pre-existing cracks in the ice had a considerable effect on the shape and propagation characteristics of the induced cracks. The fractures propagated intermittently, where the average velocity as a fracture progressed through several jump episodes was low (in the 0-50 m/s range), whereas the velocity measured at the brief jumps was in the 0-550 m/s range. Peer reviewed: Yes NRC publication: Yes