Why don't faults keep sliding past each other?
Map view looking down on a fault zone with a single asperity. Regional right lateral strain puts stress on the fault zone. A single asperity resists movement of the green line which deforms before finally rupturing.
- An asperity is an area on a fault that is stuck or locked.
- An area along an active fault that has not had an earthquake in a long time might be vulnerable to a large earthquake.
- On a long fault, adjacent areas may move, putting strain on the asperity