- Movement can occur either in sudden jolts or in a slow, steady motion called creep. Fault segments that are actively creeping experience many small to moderate earthquakes that cause little or no damage.
- These creeping segments are separated by segments of infrequent earthquake activity (called seismic gaps), areas that are stuck or locked in place within the fault zone. Locked segments of the fault store a tremendous amount of energy that can build up for decades, or even centuries, before being unleashed in devastating earthquakes.
- For example, the Great San Francisco Earthquake (8.3-magnitude) in 1906 ruptured along a previously locked 430 km-long segment of the San Andreas