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Observations in a cavity beneath grinnell glacier
Author(s) -
Anderson R. S.,
Hallet B.,
Walder J.,
Aubry B. F.
Publication year - 1982
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.3290070108
Subject(s) - geology , glacier , plucking , bedrock , debris , geomorphology , ice tongue , glacier morphology , abrasion (mechanical) , rockfall , cirque glacier , physical geography , ice stream , oceanography , geography , cryosphere , sea ice , mechanical engineering , landslide , engineering
During a 3‐year period, several aspects of the glacier‐rock interface were studied in a cavity beneath 5–8 m of ice near the terminus of Grinnell Glacier, Montana, U.S.A. Continuous week‐long records of the summer sliding rate revealed a very uniform speed of about 12 m a −1 during the summer, a value about 20 per cent higher than the average annual sliding rate. Several decimetre‐sized rock fragments were broken from the glacier bed near the lee sides of bedrock ledges and transported down‐glacier. In the course of a two‐week long experiment, the glacier abraded its bed significantly and non‐uniformly. It is of interest that significant quarrying and abrasion occurred under thin ice with relatively little entrained debris.