How do observations of earthquake and volcanic activity support the theory of plate tectonics?
The vast majority of earthquakes and volcanoes occur along plate margins. The direction of movement along transform faults matches the expected movements due to plate tectonics. The distribution of earthquakes at subduction zones matches the predicted descent angle of the plate being subducted. The pattern of historic volcanic activity associated with hot spots indicates that crustal plates are moving while the hot spots remain stationary.
