GEOL 101 Chapter Notes - Chapter 8: Richter Magnitude Scale, Mercalli Intensity Scale, Fault Scarp
Document Summary
Most earthquakes happen as a consequence of the slip on a fault. The place where rock breaks and earthquake energy is released is called the focus. The point on the ground directly above the focus is the epicenter. Active faults are ones on which movement is likely. Displacement on active faults that intersect the ground surface may yield a fault scarp. During fault formation, rock elastically bends, then ruptures. When this happens, the rock vibrates, and this generates an earthquake. Most earthquakes happen when stress overcomes friction on a pre-existing fault, and the fault slips again, again causing rock to vibrate. Faults exhibit stick-slip behavior, in that, once formed, stress builds up until they move in a sudden increment. Earthquake energy travels in the form of seismic waves. Body waves, which pass through the interior of the earth, include p-waves and s-waves. Surface waves pass along the surface of the earth.
