4.2-magnitude earthquake rattles Northern California

 An earthquake struck just south of Aetna in California, and it was felt in parts of Sacramento and the Bay Area. The earthquake, which happened on Wednesday morning and had a magnitude of 4.2, was reported by the American Geological Survey.

The earthquake hit the southern Sacramento area at 9:29 AM, shaking areas like Rio Vista and Aetna. Initially, it was reported to have a magnitude of 5.7, but it was later revised down.

Mild tremors were felt in nearby communities, including Oakley and Discovery Bay, as well as in Sacramento, San Francisco, and as far south as San Jose.No damage or injuries were immediately reported.

A quick warning was issued, instructing people to "Drop, Cover, and Hold On" in the entire region. Mobile alerts were also sent out by KCRA, linked to Sacramento's NBC affiliate.

The BART train service in the San Francisco Bay Area experienced delays. Trains were paused for five to eight minutes to inspect the tracks.

The earthquake happened 6.7 miles beneath the surface, according to the US Geological Survey.The intensity of shaking during an earthquake increases as you go deeper, which is why a 4.8-magnitude earthquake at a depth of 19.2 miles on Monday had a less noticeable impact.

This earthquake came just a day after the Great California ShakeOut earthquake drill, in which millions of people statewide practiced how to stay safe during major earthquakes.

According to the California Earthquake Authority, the majority of Californians live within 30 miles of an active fault. There are over 500 active fault lines running throughout the state.

The USGS estimates a 75% chance of a magnitude 7.0 or larger earthquake occurring in Southern California over the next 30 years.