Earthquakes usually occur along fracture zones in Earth's crust, where large tectonic plates slide past one another and become locked. Stress builds up over long periods and is suddenly released in the form of an earthquake.

Unlike the San Andreas Fault — one of the most heavily studied faults in the world — scientists know comparatively little about the Rose Canyon Fault.

SAN DIEGO (FOX 5/KUSI) — Different parts of the country have different natural disasters, like tornadoes in the Midwest or hurricanes in the South. Those in the western U.S. mostly deal with wildfires, earthquakes and droughts. But why is there more ...