The Dark Blue Bottom Of An Iceberg That Just Rolled Over

This happens when the bottom half of the iceberg pushes UP, and the top of the iceberg pushes DOWN. And of course due to the irregular shape of the iceberg, these up and down forces aren’t at all symmetrical radially. So when the top melts that means it no longer pushes downward as much, and the bottom half now pushes upwards more than the top pushes downward, and the unsymmetrical upward force rolls the iceberg onto its side in order for the bottom half to push its way upwards.