Glacier and ice sheet flow

This review of the dynamics of the flow of glaciers and ice sheets focusses on the mathematical models which have been developed to explain a number of observations in the behaviour of these large ice masses. It takes a personal view, starting with an account of the historical development of the subject, followed by a tour of some of the observational puzzles and theoretical solutions which I have found most intriguing. Most of the discourse involves basal processes: glacier sliding, subglacial hydrology, bedform generation. I describe in some detail wave ogives, surging glaciers, subglacial floods and subglacial bedforms. I variously explore issues in sliding theory: sub-temperate sliding, slip or till deformation; the rheology of till; the status of the instability theory of drumlin formation. And in an effort to broaden the field of view, I include discussion of Dansgaard-Oeschger and Heinrich events, grounding line stability, and the formation of eskers and, particularly, flutes.