Plate Tectonics
The area with the most seismic activity is the circum-Pacific belt. Most earthquakes occur along convergent boundaries where one plate slides beneath another. There are over 40,000 miles of subduction boundaries in this belt. Another area of high seismic activity is the Alpine-Himalayan belt. Earthquakes are mainly caused by the collision of the African plate with the Eurasia plate. These plates create strike slip faults.
A strike slip fault is a fault where the dominant displacement is horizontal and parallel to the direction of the fault surface.
A transform fault is a large strike slip fault that cuts through the lithosphere and accommodates motion between two tectonic plates. The San Andreas fault is an example of a transform fault.
Earthquakes can also occur along faults associated with convergent plates. They generate thrust faults.
A megathrust fault is is when a plate boundary between a subducting piece of oceanic lithosphere and the overlying plate form a fault. These faults usually lay on the ocean floor, creating tsunamis.
A strike slip fault is a fault where the dominant displacement is horizontal and parallel to the direction of the fault surface.
A transform fault is a large strike slip fault that cuts through the lithosphere and accommodates motion between two tectonic plates. The San Andreas fault is an example of a transform fault.
Earthquakes can also occur along faults associated with convergent plates. They generate thrust faults.
A megathrust fault is is when a plate boundary between a subducting piece of oceanic lithosphere and the overlying plate form a fault. These faults usually lay on the ocean floor, creating tsunamis.
Source: http://geology.com/articles/san-andreas-fault.shtml