This morning’s earthquake hit at 2.09am PST (10.09am GMT) with its epicentre 5km north east of Trabuco Canyon in California.
Tremors were felt in San Diego and the Los Angeles area.
On social media, people reported being shaken awake by the violent tremors, with one person saying there was huge “jolt”.
And one resident of Canyon Lake claimed to hear a “loud roaring sound” before the shaking began.
Alarmed LA resident Junaito Moon tweeted: “Downtown LA here.
“I was in bed and thought I felt dizzy but realised it was a quake when I saw my lamp moving.”
And US weatherman Dan Amarante wrote: “Earthquake in Southern California.
“Not a strong one, but enough to wake up a lot of people in the Los Angeles and San Diego Area.
“No tsunami risk from this.”
It came following a number of smaller ones 6km from Aromas measuring between 2.6 and 3.6 just after 6am.
The number of tremors in close proximity triggered fears the Big One could be coming.
There have been a swarm of quakes in the area this week, with nine tremors of various magnitudes picked up.
New data has revealed the fault line running through Los Angeles’ exclusive shopping district of Beverly Hills is at risk if ‘the Big One’ hits.
A new map of the region using the latest data from the US Geological Survey shows Beverly Hills – which is situated on the Ring Fire – is at greater risk from earthquakes than previously thought.