In the last 48 hours, the southwestern State in the US has been rocked by eight tremors, according to the US Geological Survey (USGS).
All but three of the tremors have come along the San Andreas fault – a deadly line which runs through California and is one of the most seismically active regions in the world.
The strongest of the quakes came in Berkeley, near the east coast of California, which measured 4.4 on the Richter scale.
Californian residents took to social media to share their experiences of the earthquakes, with many fearing that the worst is yet to come.
Xavier D wrote on Twitter: “It hasn’t even been a full week of 2018 and God is out here really trying to end California.”
Charlie posted: “The scariest part about every California earthquake in the 21st century is having to wonder whether this is the ‘Big One.’”
A user by the name of Hnin warned: “Okay that earthquake was way too strong for me to pretend like California isn’t gonna split in half soon”.
Experts have previously warned small earthquakes along the San Andreas Fault could lead to a larger one in the future.
Thomas Jordan, head of the Southern California Earthquake Center, told the Los Angeles Times last year: “Any time there is significant seismic activity in the vicinity of the San Andreas Fault, we seismologists get nervous.
“Because we recognise that the probability of having a large earthquake goes up.”
California sits on top of the potentially catastrophic fault, a chasm between two massive plates of the Earth’s crust that extends hundreds of miles across the country.
Also, beneath California, the Pacific and North American tectonic plates are moving northward – although the former is moving quicker leading to a build up of tension.
A powerful earthquake in 1857 released some of this pressure, but much more still exists, and Robert Graves, a research geophysicist at USGS, suggests the Big One could be overdue by 10 years.
He told Raw Story: “The San Andreas fault in southern California last had a major quake in 1857 (magnitude 7.9).
“Studies that have dated previous major offsets along the fault trace show that there have been about 10 major quakes over the past 1,000-2,000 years… the average time between these quakes is about 100-150 years.”