The Earth in action; geography of earthquakes and volcanoes and catastrophic events in historic times; size and frequency of occurrence of earthquakes and volcanic eruptions; the products of volcanism, volcanic rocks, and volcanic and geologic activity through geologic time; volcanic exhalations and the evolution of the Earth's atmosphere and oceans; the relationship of earthquakes and volcanoes to plate tectonics and the internal dynamics of the Earth; and volcanism and geothermal energy, man-made earthquakes, and earthquake prediction and control.