The full programme book (PDF) - Royal Geographical Society

THEME 5: ICE SHEET DYNAMICS
Retrospect and prospect: understanding ice sheets ancient and modern
Geoffrey Boulton
School of Geosciences, University of Edinburgh, Grant Institute, Kings Buildings, Edinburgh EH9 3JW
Science progresses in fits and starts, sometimes as a consequence of creative,
unanticipated insights or observations and increasingly because of application of new
technologies. Louis Agassiz’s bold deductions from erratics on the Swiss Plain about the
former extent of alpine glaciers, and his extension of the theme to the glaciation of
northern Europe and North America, was the most creative, in envisaging a past world
unimaginable different from the present, and was the motivating concept for the
development of palaeoclimate science. The early work on the extent and character of
Pleistocene ice sheets long preceded significant discoveries of the character of modern
ice sheets.
From the 1950s onwards, the glaciology of modern ice sheets and glaciers developed
apace, progressively correcting some of the errors that had arisen from study of ancient
landforms and sediments uninformed by modern process studies. We began to
understand the rheology of ice, the physical basis for the form of ice sheets, the existence
of ice streams as crucial ice sheet dynamic components, the hydrology of glaciers and the
nature of the coupling between ice and bed. From the 1970s, these discoveries began to
influence the reconstruction of Pleistocene ice sheets and their properties, leading to
greater convergence between modern- and palaeo-glaciology. The former contributes
knowledge of ice processes and large-scale system dynamics, the latter knowledge of the
bed mosaic, long-term ice sheet evolution and major, but infrequent events such as
Heinrich events. This latter convergence continues, powerfully developed through the
space-borne capacity to image large areas of former and modern ice sheet terrains in
great detail, and to deduce their properties. It is a trend that should be sustained.
Keywords: ice sheet dynamics; palaeo-glaciology