Some earthquakes occur when tectonic plates, large sections of Earth'scrust and upper mantle, move past each other. Earthquakes along the San Andreas and Hayward faults in California occur because of this. Earthquakes also occur if one plate overruns another, as on the western coast of South America , the northwest coast of North America , and in Japan. If plates collide but neither is overrun, as they do crossing Europe and Asia fromSpain to Vietnam, earthquakes result as the rocks at the abutting plates compress into high mountain ranges. In all three of these settings, earthquakes result from movement along faults.