Chandeliers swayed and china cabinets rattled, but there were no immediate reports of injuries or serious damage as a strong earthquake shook Central California on Tuesday. The quake, which struck at 10:15 a.m. Pacific time, had a preliminary magnitude of 6.0, according to the U.S. Geological Survey.

Centered nine miles south of the farm community of Parkfield, the tremor was felt for hundreds of miles, from Sacramento to Los Angeles. Dozens of aftershocks, including one measuring 5.0 four minutes after the main quake, rattled the area throughout the day.

"It wasn't a sharp shock. It wasn't really a rolling shock either. It just sort of rumbled," said Joanne Dismuke, who felt the quake at her home about 10 miles from Parkfield. "We had a broken glass or two, but other than that, I think we're really lucky."

Two people were killed when a 6.5 quake hit nearby Paso Robles in December, the state's first fatal earthquake since the 6.7-magnitude Northridge earthquake killed 57 people in 1994.

Preliminary inspections by state and local emergency officials turned up no apparent injuries or damage caused by Tuesday's earthquake.

"If a 6.0 quake had occurred in an urban Third World country, we would have thousands of people dead," USGS spokeswoman Stephanie Hanna said. "This is earthquake country, and people know that earthquakes are going to occur here. This is a testament to the strong building codes and the personal precautions that people are taking at their homes and businesses."

Located on the San Andreas fault, Parkfield, population 37, is known as the earthquake capital of California. Six similar magnitude earthquakes have been centered here -- occurring approximately once every 25 years, Hanna said.

While ongoing aftershocks unnerve residents, scientists said, the earthquake presented a unique opportunity to learn more about how seismic shakeups occur.

Because of the frequency of quakes at Parkfield, scientists set up monitoring equipment to catch a quake in action. They dubbed the project, launched in 1985, the Parkfield Experiment. A large-magnitude earthquake was expected to occur by 1988.

"It is overdue, but we finally caught it red-handed," said Susan Hough, a seismologist with the USGS in Pasadena. "Usually when earthquakes occur, we don't have equipment pointed at the fault waiting to see what happens. This will give us a much better idea of what was happening on a fault before, during and after an earthquake occurs."

Hough said data retrieved Tuesday could help scientists better understand just how earthquakes get started, which could improve their ability to predict when and where temblors will occur.