Hi Todd.The main force that shapes our planet’s surface over long amounts of time is the movement of Earth's outer layer by the process of plate tectonics.

Movements deep within the Earth, which carry heat from the hot interior to the cooler surface, cause the plates to move very slowly on the surface, about 2 inches per year.

Most of the quakes occur near the surface. There are caused when one plate moving past another locks. It’s at the point of locking that quakes occur. If it stays locked for a long period of time we could get one major quake, or a series of moderate quakes.

We have small quakes in the Hollister area all the time most of which are never felt. The reason being is that it appears that there is nothing along the Calaveras Fault in this area large enough to cause the fault to lock long enough to cause a felt quake. It just creeps along one little bump after another. It hasn’t always been that way though. The creep we are experiencing now started in 1929. Have no idea as to why it started then.

When the fault locks at a given point nothing moves. However everything around the locked point continues to move. If it didn’t we wouldn’t have any quakes. Stress starts to build at the locked point until a point is reached that the locked point can no longer resist moving. It could break with just a little stress, (small quake) or it may take a whole lot of stress to break it (large quake.) Take Care…Don in creepy town

• Cause of Earthquakes