SACRAMENTO, Calif. – A moderate earthquake thought to be a magnitude 5.5 rumbled under Northern California Thursday, sending tremors through the region and residents onto social media to figure out if the ground’s shaking was, in fact, an earthquake.
The United States Geological Survey reports the quake struck about 4:19 p.m. local time and was centered about 2.5 miles southwest of East Shore, California.
According to initial reports, the quake was shallow, which caused a large region to feel the shaking. Witnesses report the ground shook in Sacramento and even as far away as Reno, Nevada.
The National Weather Service Office in Sacramento, about a three-hour drive south of the epicenter, reported minor motion and window blinds swaying.
According to seismologists, the quake was not considered to be volcanic-induced, and a tsunami threat along the eastern Pacific Coast was quickly ruled out.
Damage assessments in the Golden State are currently underway, but the California Highway Patrol has already stated that 911 lines in the area around Plumas County were down.
Some residents reported receiving an alert on their phones in the moments before the earthquake.
The alert message stated: "Earthquake detected! Drop, cover, hold on. Protect yourself. -USGS ShakeAlert."
The USGS said since the quake was greater than a magnitude 5.0, an alert was sent to phones in the immediate area.
The U.S. National Earthquake Information Center reports that 12,000-14,000 earthquakes occur annually. Usually, California experiences two or three earthquakes large enough to cause damage to buildings.