– Explain the theory of continental drift. Describe and explain at least three lines of evidence that Alfred Wegener used to support his theory of continental drift and the existence of the supercontinent Pangaea. Explain the theory of plate tectonics. How does the theory of plate tectonics help explain the idea of continental drift? Apply your knowledge of plate tectonics to explain the frequent occurrence of earthquakes and volcanoes along the Circum-Pacific Belt (Ring of Fire). Why is earthquake hazard high in California?