Plate Tectonics play a huge role in the earth's form and terrain. There are numerous plates that are moving from pressure and heat; this causes earthquakes. The San Andreas Fault is an area that is moving and shifting all the time. It runs from about Eureka in Northern California all the way south towards Brawley passed Desert Hot Springs. There are some areas where you can visibly see the effects of the shifting of the plates like the picture above. Just like the way San Andreas Fault runs North to South it is also shifting that way, on one side, it is being pushed towards Mexico, and on the other, it is going towards Oregon, north of California. This is called a Transform Plate Boundary as it consists of two plates grinding alongside each other that causes earthquakes.