The force vector from a polar ice sheet doesn't get cancelled out by the rest of the earth though (because they aren't pointing in opposite directions). Plus, you have to account for the force of the ice sheet, plus the water it attracts, plus the water that those combined attract, etc.
I'm no good with calculus so can't run that back-of-the-envelope for you, but it doesn't seem all that surprising to me.
I'm no good with calculus so can't run that back-of-the-envelope for you, but it doesn't seem all that surprising to me.