Velocity pattern in a transect across Ice Stream B, Antarctica

Abstract Repeat aerial photography is used to obtain closely spaced measurements of velocity and elevation over a complete transect of Ice Stream tributary B2, including the shear margins, the fast ice of the ice stream and several unusual features, as well as the UpB camp. Persistent features, main...

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Bibliographic Details
Published in:Journal of Glaciology
Main Authors: Whillans, I. M., Jackson, M., Tseng, Y-H.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1993
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000016452
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000016452
Description
Summary:Abstract Repeat aerial photography is used to obtain closely spaced measurements of velocity and elevation over a complete transect of Ice Stream tributary B2, including the shear margins, the fast ice of the ice stream and several unusual features, as well as the UpB camp. Persistent features, mainly crevasses, are tracked to provide 1541 values of velocity and 1933 values of elevation. These are used to describe ice flow in the ice stream. Within the ice stream, the dominant velocity gradient is lateral shear. Crevasse patterns are studied in relation to measured velocity gradients. Crevasses intersect one another at acute angles, indicating that their origin is deeper than the depth to which crevasses penetrate. One feature within the ice stream seems to be a raft of stiff ice. Others are crevasse trains. Also, there are spreading ridges, perhaps due to upwelling ice. There is no evidence of large sticky spots within the studied transect, i.e. no steep surface slopes with associated surface stretching just up-glacier and surface compression down-glacier.