A groaning, creaking and brittle cracking, its source invisible. The sound though not loud is unearthly as some creature in mortal agony shrieks. To my eye, all is motionless. There is no wind, only the rise in temperature caused by the sun. I feel a nudging of my boots, and looking down see that the 1/2 thick plate ice is walking ashore, bending when it meets resistance until it breaks.