Why are the Hayward, Concord, and Calaveras Faults present along either side of the San Andreas FAult?

One comment

1. 

   Mark V on September 7, 2010 at 12:56 am

   Because there is almost never just one sole, lone fault sitting all by itself, especially when you’re talking about a very large area with a very powerful plate boundary. That’s why we call it the San Andreas Fault Zone – not just Fault. It has dozens of minor, and very minor faults running off to either side. Down there in Southern California, our crust is shattered into dozens of tiny microplates, all of which owe their existence to the SAFZ.

   We here at the confluence of the Pacific plate and North American plate are witness to some incredible geology and tectonics. When you have that much mass, and that much energy, and thus, that much strain involved, you’re going to have to fracture over a larger area than just one single line. You just can’t do it any other way. That’s why you end up with Hayward, Concord, Calaveras, and all the others that make life in this state interesting.

   Even this unfortunate earthquake that we just had in Haiti took place over the Enriquillo-Plantain Garden Fault Zone. Not "fault" singular. Just too much energy to store in any one place.