Glaciers

摘要

Its not often that glaciers take centre stage on the covers of the most prestigious general science journals and so it is fitting to start off this review article with reference to two small offerings by glacial researchers to Nature in an issue whose cover is emblazoned with an image of the Matanuska Glacier in Alaska. The scientific breakthrough that merits this high-profile treatment is the discovery of supercooling in overdeepenings at glacier beds, a subject that figures significantly in previous Glaciers reviews in PIPG (Evans, 1999, 2001). The impact of the supercooling process is reviewed by Piotrowski (2003) and then applied by Alley et al. (2003) to a model of stabilizing feedback in the erosion of glacier beds. Examples of possible supercooling are now coming into print thick and fast (e.g., Roberts et al., 2002) but one can not help feeling that glacial researchers can be their own worst enemies by latching on to a newly proposed process–form relationship and promoting it almost to the exclusion of all other equally plausible mechanisms (see Knight, 2003).