Formation of the sliding terrain due to ice pack instability. In panel (a) the water is retreating and one part of the ice floe (left) rests on a higher area (“local hill”), while the part on the right still floats on the water. As the ocean retreats (panel (b)), the tension across the ice crust grows (panel (c)) until failure occurs (panel (d)) and the ocean floor is exposed, which corresponds to observed terrain sliding due to gravity.