Skip to main content
Article
Geometrical Force Balance in Glaciology
Journal of Geophysical Research-Solid Earth
  • Terence J. Hughes, University of Maine - Main
Document Type
Article
Publication Date
11-15-2003
Disciplines
Abstract/ Summary

The analytical force balance traditionally used in glaciology relates gravitational forcing to ice surface slope for sheet flow and to ice basal buoyancy for shelf flow. It is unable to represent stream flow as a transition from sheet flow to shelf flow by having gravitational forcing gradually passing from being driven by surface slope to being driven by basal buoyancy downslope along the length of an ice steam. This is a serious defect, because ice streams discharge up to 90% of ice from ice sheets into the sea. The defect is overcome by using a geometrical force balance that includes basal buoyancy, represented by the ratio of basal water pressure to ice overburden pressure, as a source of gravitational forcing. When combined with the mass balance, the geometrical force balance provides a holistic approach to ice flow in which resistance to gravitational flow must be summed upstream from the calving front of an ice shelf. This is not done in the analytical force balance, and it provides the ice-thinning rate required by gravitational collapse of ice sheets as interior ice is downdrawn by ice streams.

Citation/Publisher Attribution
Hughes, T, 2003, Geometrical Force Balance in Glaciology: Journal of Geophysical Research-Solid Earth, v. 108, p. 2526. To view the published open abstract, go to http://dx.doi.org and enter the DOI.
Publisher Statement
© Copyright 2003 American Geophysical Union
DOI
10.1029/2003JB002557
Version
publisher's version of the published document
Citation Information
Terence J. Hughes. "Geometrical Force Balance in Glaciology" Journal of Geophysical Research-Solid Earth Vol. 108 (2003) p. 2526
Available at: http://works.bepress.com/terence_hughes/22/