Problem: Make a definition sketch and show your work when solving this problem.
Calculate the expected deflection of the lithosphere beneath a thick ice sheet. Assume that the ice is 4000 m thick, and that ice has a density of 917 kg/m³ (the Antarctic ice sheet is roughly this thick at its maximum thickness.) The thickness of the crust (of density 2700 kg/m³) beneath the center of the ice sheet and the region outside of it is the same. The density of the upper mantle that escapes to allow this deflection of the surface is 3300 kg/m³. How far down is the rock depressed beneath the load of the ice?