Monday started off with a jolt in San Diego County, as a 4.1 earthquake rocked the region.
The U.S. Geological Survey reported the moderate quake hit around 4:35 a.m. about 10 miles north of the Palomar Observatory and about 20 miles east of the Riverside County community of Temecula. It was followed by a magnitude-3.8 aftershock five hours later, the USGS said.
The quake was felt across the county, with reports from residents ranging from Alpine to Golden Hill and all the way east to Palm Desert. There are no reports of damage or injuries.
One resident described the experience in an e-mail: "At 4 or 4:30 a.m., I woke up and rolled over and felt a bump that actually felt like it moved me in the center of my back. I knew it was not normal. I thought a big truck hit the building. But you see, I am on the 18th floor of a high rise on Noble and the I-5."
The quake comes just days after all of Southern California participated in an earthquake drill -- in the event of a 7.8 magnitude quake on the San Andreas Fault.
For more on the earthquake, check out the U.S. Geological Survey's Web site.