Special look into San Andreas Fault

COACHELLA VALLEY, Calif. (KSAZ) - Just a few months ago scientists announced the San Andreas Fault is due for another major earthquake, specifically in Southern California where there hasn't been a major quake since 1857.

The Coachella Valley near Palm Springs could be one of the areas hardest hit.

In the arid, sweltering Coachella Valley lies the southern part of the San Andreas, one of the most dangerous faults in the world. Experts say this area has been quiet for far too long.

"On the Southern end of the San Andreas Fault we've not had a major one in years," said Phil La Greca of Desert Adventure Red Jeep Tours.

Phil La Greca leads FOX 10 right into the fault on a Desert Adventures Jeep Tour.

Driving through the Indio Hills we straddle two tectonic plates; the Pacific Plate under Palm Springs and the North American Plate under Arizona. Where the two plates meet you find the San Andreas Fault.

"The misnomer in the SA fault it's a big ioen crack, it's not. It's those 2 plates are moving together and whenever you get a little movement in that plate a crack or something like that, that's an earthquake," said La Greca.

The fault zone ranges from 100 feet to two miles wide. Each of the plates moving two inches a year, crushing rock and stone between.

"If you take an Oreo cookie and you squeeze and Oreo cookie together the cream comes up. That's how these hills were formed," said La Greca.

That "cream filling" is called "fault gouge" - the soft foundation of these tall walls.

There has not been a major quake here 300 years. And one expert says the fault's "locked, loaded and ready to go".

"Remember I told you we had nothing to worry about over there if we had an earthquake?"

Inside the Horseshoe "slot canyon" you'll find towering walls smoothed by wind and water. And eroded pockets, large enough to sit in.

It cannot be said with 100 percent certainty that this is where the Pacific plate and the North American plate meet.

The fault zone isn't all rocks and dust, it also has a has a "Palm Oasis" packed with California Fan Palms.

"It's almost like a jungle here right in the middle of the desert. There's water coming right up from the ground," said La Greca.

This entire dessert, green and grey, sees two to three hundred quakes a week. Most too small to feel.

"While we were having almost 800 in California and Nevada, you only had it looks like 3 in the entire state of Arizona. So you guys are okay. We are the ones who have to worry more than you do," said La Greca.

There are several faults that run through Arizona. As for the recent earthquakes that have been seen in Arizona, geologists still are not sure which fault caused them. The closest is the Horseshoe Fault which is 22 miles southeast of Black Canyon City.

To learn more about the Red Jeep San Andreas Fault Tour, click here.