Aleutian Islands, Alaska
Alaskas Aleutian Islands mark the northern rim of the Pacific Ring of Fire, a region of volcanic activity surrounding the Pacific Ocean. On the south side of the Islands is the Aleutian trench, an almost unfathomably deep depression caused by the bending of the Pacific Plate as it is it pulled underneath the adjacent continental plate by tectonic forces. The circular white patches of some of the volcanoes snow-filled craters can be seen up and down the island chain.