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A reply to ‘a discussion of hirano and Aniya's (1988, 1989) explanation of glacial valley cross profile development’ by Jonathan M. Harbor
Author(s) -
Hirano Masashige,
Aniya Masamu
Publication year - 1990
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.3290150409
Subject(s) - glacial period , geology , cross section (physics) , mathematical economics , mathematics , physics , paleontology , quantum mechanics
Abstract The extremum principle is again justified as a valid and relevant approach to cross sectional form of the glacial valley. It is accepted that the extremum previously obtained was a maximum, and not a minimum for friction, but this still appears to be a valid application of the principle. Harbor's more detailed discussion is recognized as valid assuming the presence of appreciable water pressures, and that Hallet's theory is to be preferred over Boulton's, but these assumptions do not always seem appropriate. While the importance of time for valley evolution is fully accepted, the extremum approach is still thought to be useful, for example in maximizing cross section for a given resistance.