Earthquakes and plate tectonics
Part of Hall of Planet Earth.
Part of Hall of Planet Earth.
Most earthquakes occur at plate boundaries. Where plates spread apart, earthquakes are shallow and small. Where plates slip past each other, they are shallow but frequently large. The San Andreas Fault is one such boundary. Where plates collide, earthquakes mark zones where one plate dives beneath another. These earthquakes occur at various depths, from shallow to deep. The Great Alaskan Earthquake of 1964, one of the largest ever recorded, took place at a collision plate boundary.