3.1-magnitude quake wakes up San Francisco Bay Area, USGS reports

A 3.1-magnitude earthquake near San Jose woke up people across the San Francisco Bay Area in California, the U.S. Geological Survey reports.

The 5-mile deep quake hit near Alum Rock in the South Bay at 5:40 a.m. Pacific time, according to the USGS. Dozens of people from as far away as Palo Alto and San Bruno reported feeling the tremor to the agency.

“Why do earthquakes always happen in the middle of the night?” read one post on Twitter after the early morning quake.

“Felt that,” read another Twitter post. “Like my whole apartment was cracking its back.”

Magnitude measures the energy released at the source of the earthquake, the U.S. Geological Survey says. It replaces the old Richter scale.

Quakes between 2.5 and 5.4 magnitude are often felt but rarely cause much damage, according to Michigan Tech.

This story was originally published August 2, 2020 at 6:37 AM with the headline "3.1-magnitude quake wakes up San Francisco Bay Area, USGS reports."