California's SAN JOSE (KRON) — The Calaveras Fault strike-slip fault line produced an earthquake with a magnitude of 5.1 and subsequent aftershocks, according to the U.S. Geological Survey.

The San Francisco Bay Area had not witnessed an earthquake of this magnitude in eight years when it shook San Jose just before noon on Tuesday. At a depth of 6.1 kilometers, the epicenter was located on the east side of San Jose. Two aftershocks, with magnitudes 2.9 and 3.5, were noted by the USGS.

In the last ten years, the Calaveras Fault has not experienced any earthquake activity. Around this time last year, in October 2007, the 5.4-magnitude Alum Rock earthquake erupted, which was its most recent significant earthquake.

The magnitude-6.2 Morgan Hill earthquake in 1984 and the magnitude-5.9 Coyote Lake earthquake in 1979 were both caused by the same fault line.

According to the Working Group for California Earthquake Probability, there is an 11% chance that an earthquake of magnitude 6.7 or higher will occur on the Calaveras Fault during the next 30 years.

Emergency personnel in San Jose reported no severe damage or casualties an hour after Tuesday's earthquake.

"We're delighted to report no emergency calls due to this morning's earthquake," the San Jose Fire Department wrote. There have been no reports of injuries or damage, according to the San Jose Police Department. If that changes, we'll let you know. We'll now resume our regularly scheduled programming to fight crime and maintain public safety.

Depending on their proximity to the epicenter, inhabitants of the Bay Area experienced motion in very diverse ways.

According to seismologist Lucy Jones, "The Earth generates energy. At the epicenter, an earthquake starts. The fault is where the waves originate. If you're close by, you can feel all of that energy and it moves extremely quickly. The high frequencies decay more quickly than the low frequencies when the waves move through space. Energy with a long wavelength travels further. Therefore, all that is left when you are far away, in San Francisco, is that long period motion.

According to Cal OES, 100,000 households were alerted ahead of time before the shaking began by the state's earthquake early warning system. People in San Francisco received an advance warning of 18 seconds, compared to San Jose residents who were only two seconds away from the epicenter.