5.1 Calif. earthquake may have been on worrisome Puente Hills fault

The Friday night 5.1 magnitude earthquake may have been on the fault that scientists constantly fret about because of its location in California.

As previously reported, the earthquake hit the Los Angeles area and is believed to have originated around Brea. The earthquake was followed by numerous aftershocks and cause minor damage and a few injuries from a rolled car.

The earthquake may have been along the dangerous Puente Hills thrust fault that runs beneath much of Orange County, the San Gabriel Valley and downtown L.A., the Los Angeles Times reports. That fault is more worrisome to seismologists than the more well-known San Andreas fault. That fault runs along the outskirts of the big cities in Southern California.

The Puente Hills fault is also different from most faults in the area because it is horizontal, compared with the more usual vertical crack-type others are.

Many scientists believe that a 7.5 magnitude earthquake on the Puente Hills fault could be much more dangerous and cause much more damage and loss of life. This one was only a decent-sized 5.1, but those 10 miles away from the epicenter were still reeling and dealing with toppled furniture.

Caltech seismologist Egill Hauksson said that the U.S. Geological Survey believes the Friday night earthquake originated close to the fault line.

The Puente Hills fault is estimated to have a major earthquake about once every 2,500 years, though scientists aren't sure when the last one was.