ABSTRACT
The response to climate change of the East and West Antarctic ice sheets differs markedly from that of ice masses in lower latitudes. It is so cold that a change in temperature of a few degrees directly affects only the marginal ice shelves. These are generally floating but are grounded here and there. If melting should reduce the extent or thickness of the shelves, it has been argued, they would be liable to lift off the seabed and become more mobile, allowing continental ice from inland to move seawards more easily (Morgan et al. 1991). An increase in the velocity and calving of ice fronts might then cause icestreams issuing from the icecaps to accelerate, the effect progressing upstream into the interior. The whole deglacial process might then be accentuated by the feedback effect of the accompanying rise in sea level but the time lag between climatic change and marginal shifts would necessarily be lengthy.
