A breathtaking look at the great circle of volcanoes and seismic activity that rings the Pacific Ocean. Witness the birth of a new volcano in Chile and take a look back in history at the infamous 1980 eruption of Mount St. Helens. March with the inhabitants of Sakurajima, Japan, as they participate in their annual evacuation drill, and witness one of the frequent ash eruptions of this very active volcano. Computer animation sequences take you on a wild through the center of the earth to see the process of the geological forces that cause a volcanic eruption or earthquake. Finally, observe the devastating results of these forces through the scenes of the 1989 earthquake that rocked the city of San Francisco.