Where do earthquakes happen? Part of the Exploring the Earth Using Seismology poster. Earth’s outer surface, the Earth’s crust, is broken into what geologists call tectonic plates. These plates move under, over, or slide past each other. The plates are driven by hot mantle materials that convect. The relative motion of plates is associated with earthquakes. Most earthquakes occur along the edges of large plates. The arrows on the map above indicate how fast the plates are moving in millimeters per year.