Properties of ice sheets
Check out some of the physical properties of ice from the links in
the following paragraphs.
Because ice is less dense than water, the temperature at which ice melts
decreases with increased pressure. A lower melting point might affect the
potential size that hypothetical former ice sheets located in the earth's
temperate zones might attain, since unless temperature within the former
ice sheet remained well below freezing, pressurized ice deep in the ice
sheet would very likely melt, and limit the ice thickness. On the other
hand, if the ice thickness at the centre was too little, there could be
no radial flow of ice towards the perimeter, and the glacial interpretation
of landforms such as drumlins would fail. Check out this page for interactive
calculations of the Pressure and Melting Temperature
at the base of an ice sheet for various thicknesses of a hypothetical ice
sheet.
Almost all the work that former continental ice sheets are thought to
have done upon the landscape, eroding bedrock and forming drift, distributing
it over the land, creating landforms such as drumlins and flutings, excavating
lake basins and fjords, etc., must ultimately depend upon the gravitational
potential energy of the ice in an ice sheet due to its elevation. Because
of the potential energy, ice sheets move and abrade the surface rocks underneath.
But is the potential energy of a hypothetical former continental ice sheet
adequate to accomplish all the work that is involved in excavating deep
rock basins in the hardest of rocks? Go here to interactively
estimate the Potential
Energy of an ice sheet.