What causes earthquakes along the San Andreas fault in California?
San Andreas is a transform fault with two plates sliding past each other. There is also a large bend in the fault (around the LA area). Basically, since these are large rocky plates and not water or something else slippery, they get stuck and tension builds up. When that tension is released as the plates slip, you get an earthquake. The bend makes it more difficult for the plates to slide past each other, which creates more tension, which is why there is such potential for the “big one.
