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Topography and ice sheet growth
Author(s) -
Payne Antony,
Sugden David
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.3290150705
Subject(s) - ice sheet , geology , greenland ice sheet , ice sheet model , ice stream , ice divide , geomorphology , climatology , sea ice , cryosphere
This paper uses a numerical ice sheet model to investigate the role of topography in influencing ice sheet growth. The model is applied to the maritime, mid‐latitude uplands of Scotland and relies on a series of assumptions about mass balance, topography, and ice flow. It is driven by an imposed pattern of temperature change. The model is able to predict effectively the extent and thickness of the Loch Lomond ice sheet, using a palaeotemperature curve based on Coleoptera assemblages. A series of experiments with a stepped, constant July air temperature depression suggests that in Scotland a change in excess of −3·0°C is necessary to initiate ice sheet growth; that steady state ice caps build up at changes of −3 to − 6·5°C; and that large ice sheets build up at changes of more than − 6·625°C. The bifurcation revealed by the last two types of behaviour is the result of topography. Both the vertical amplitude and the spatial distribution of bedrock basins and ridges are important in determining the pattern, rate, and extent of ice sheet growth. The implication is that topography plays an important role in determining the dynamics of ice sheet growth.