A light earthquake was felt widely in Southern California before dawn Tuesday but there were no reports of damage.
The magnitude 4.5 tremor occurred at 4:49 a.m. beneath the rugged San Bernardino Mountains in the inland region about 100 miles (160 kilometers) east of Los Angeles and about the same distance north of San Diego.
More than 9,000 people used the U.S. Geological Survey's citizen reporting website to say they felt it, but the Riverside County Fire Department received no reports of damage or injuries.
The quake occurred 8 miles (13 kilometers) beneath wilderness north of Cabazon, a lightly populated desert community best known to travelers along Interstate 10 as the location of giant dinosaur statues, a casino resort, outlet stores and giant spinning windmills that turn the gusty winds of San Gorgonio Pass into electricity.
"You heard the shaking before you felt it," Cristina Candelaria told KABC-TV in Redlands, about 30 miles (48 kilometers) west of Cabazon.
Veteran seismologist Lucy Jones tweeted that the quake occurred near a complex part of the San Andreas fault that cannot be clearly seen on the surface there because it is covered by another fault. She said the movement was mostly that of a thrust fault in which one side moves up over the other side.
The 4.5 quake was followed by a smaller 3.2 aftershock and numerous micro quakes, according to the USGS.
Quakes of such size generally don't cause any significant damage.
"I slept through it," Jones tweeted.
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