A strong 5.1 earthquake rocked the San Francisco Bay area today, shaking a broad area around San Jose, California. According to the California Geological Survey, the earthquake was likely on the Calaveras fault zone. Shaking was felt throughout the Bay Area with moderate shaking reported near the epicenter & weak shaking felt beyond that. No significant damage was reported. Currently, there’s been 14 aftershocks , 5 of which that had a magnitude of 2 or greater. Today’s earthquake was the largest Bay Area quake since the magnitude 6.0 event in Napa in 2014.

The San Jose Fire Department said it hadn’t received any emergency calls related to the quake, but shaking was felt across a broad area.

According to USGS, the magnitude 5.1 event unfolded at 11:42 am local time at a depth of 4 miles, just south of Mount Hamilton roughly 12 miles east of downtown San Jose. A magnitude 2.9 aftershock struck 5 minutes later at 11:47 am followed by a magnitude 3.6 aftershock at 3:08 pm.

“According to our forecast, there is a 1% chance of one or more aftershocks that are larger than magnitude 5, which can be damaging, within the next week,” USGS said in an aftershock forecast bulletin. “There will likely be smaller aftershocks within the next week, with up to 5 magnitude 3 or higher aftershocks. Magnitude 3 and higher aftershocks are large enough to be felt nearby. The number of aftershocks will decrease over time, but a large aftershock can temporarily increase the number of aftershocks.”

USGS estimates the chance of more aftershocks within the next week until November 2, 2022 as follows:

- There is a 60% chance of magnitude 3 and above aftershocks within the next week, and it is most likely that 0 to 5 of these will occur.
- There is a 11% chance of magnitude 4 and above aftershocks within the next week, and it is most likely that 0 to 1 of these will occur.
- There is a 1% chance of magnitude 5 and above aftershocks within the next week, such an earthquake is possible but with a low probability.
- There is a 1% chance that this earthquake becomes a foreshock to a larger earthquake (magnitude 5.06 or greater) in the next week, such an earthquake is possible but with a low probability.
- There is a 1 in 800 chance (0.1%) of magnitude 6 and above aftershocks within the next week, such an earthquake is possible but with a low probability.
- There is a 1 in 8,000 chance (0.01%) of magnitude 7 and above aftershocks within the next week, such an earthquake is possible but with a very low probability.