Calaveras Fault - Hollister, CA - Wikipedia Entries on Waymarking.com

The San Andreas Fault is the largest fault by far in California. It is over 800 miles long from Eureka to the Salton Sea. The Calaveras Fault is an offset of the San Andreas Fault network. It is about 100-150 miles in length. It starts about 15 miles east of Salinas at the San Andreas and continues northward toward Oakland, where it becomes the Hayward Fault. In Hollister, the fault is creeping which means that it moves constantly, at a steady rate. This rate is about the same rate as finger nails grow, two inches per year.

Because the earth is constantly in motion here, that has some side effects which can be a great insight from the mind of a geologist. Number one, there are little to no earthquakes along this fault. This is a good thing for buildings and contractors, especially homes. No earthquakes mean no worry of collapse. But there are earthquakes that can be felt from the San Andreas Fault, only 20 miles away. There are no earthquakes that are produced from the Calaveras Fault. If there are, then they are a 3.0 or lower on the Richter scale, too small to be felt. Another reason why this is a good thing is that it is a great place to study the earth in motion. Unlike the San Andreas Fault where most of it is locked, the Calaveras Fault is creeping. It is hard to study a fault that may or may not move at all in our life time. But, here in Hollister, the Calaveras Fault is a measurable place to see the earth in actions.

Before I go into any more details lets first discuss the basic fundamentals of how fault lines are created and now they work. The answer can be found in your kitchen, literally. When boiling pasta on the stove, the hotter pasta floats to the surface then when it cools it sinks. This effect has a name. Convection currents in your pot at home and in the earth are nearly identical. There are a few difference though. One is with water, rather than boiling rocks and the other is that one is less a few inches while one is miles deep. Convection currents are continues cycles in the earth's mantel that make hotter rock rise, and cooler rock fall and the cycle begins over and over again. When this happens, it causes fractures in the earth's crust. When fractures occur, a fault line is created. When they move in a circular pattern in one direction, they can push rock with them. When tension is released you get an earthquake in an that moves in waves on the X, Y, and Z axises. X is up or down, Y is right or left, and Z is pivoting side to side.

Depending on the pressure, it can create a magnitude 1 earthquake on the Richter Scale or a 10. A 10 has never happened in recorded history, but is believed to have only occur when large meteors hit the earth. The largest earthquake ever recorded happened in Chile on May 22, 1960. It happened in open waters, just off the coast in the Pacific where it created a Tsunami. You can see my earthcache about that Tsunami here. A Richter Scale works like this. Say there was a 5.0 earthquake, which are common, and a 7.0, a little less. A 7.0 on the Richter scale is 100 times greater of that of a 5.0 on the same scale. Each decimal point in-between is twice as as bad as the preceding one.

There are different types of slip slip fault like this one. They vary depending on what direction they are moving, relative to the other. You can tell my a simply trick. Stand one one side of the fault and look to the other. If the direction of motion on the other side is moving to your right, then it's a right-lateral strike strip fault. If it's moving to your left, then it's a left-lateral stick strip fault.

The following are my cited sources. I got the information from there, but did not copy. http://sepwww.stanford.edu/oldsep/joe/fault_images/hollmapA.html

http://pubs.usgs.gov/gip/dynamic/tectonics.html