I am interested in how fast the Greenland ice cap could melt. For example, if water gets down to the base of the icecap (to the rock/sediment surface), could it just sort of float off? Isn't it surrounded by mountains along the edges? Isn't the middle depressed by the mass of the ice? The latest is that outlet glaciers in southern Greenland have doubled their rate of ice flow to ocean in last few years. I hear a talk that once the elevation of the surface of the ice falls below a certain level the ice cap is doomed to melt...and this makes a lot of sense...but how fast? I talked to a relatively well-known geologist last month who thinks it could melt this century...by sliding fast into the sea rather than melting in place. Chris