California rocked by swarm of five earthquakes in just 48 hours

Residents in California experienced a swarm of five earthquakes within the last 48 hours.

A 4.4-magnitude was felt in the north around Lake County on Saturday and two more struck the area the following evening, ranked as a 2.7 and 2.8-magnitude.

Locals in southern California also reported two more quakes on Saturday, with the largest ranking a 3.9-magnitude. 

Northern California typically sees a spate of about 50 earthquakes per month, experienced two quakes this weekend, in addition to the two felt in the southern area of the state.

The 2.7-magnitude earthquake struck Covelo shortly after 12pm PT on Sunday and the second 2.8-magnitude occurred at 10:52pm PT that same day.

These reports came a mere day after residents in southern California received a ShakeAlert, which notifies people of an impending quake and warns them to take cover - moments before it hit. 

The first measured 3.5 on the Richter scale as it struck at 10.05am local time.

The epicenter was 4.3 miles southeast of Ontario, according to the U.S. Geological Survey.

The second, stronger 3.9 magnitude quake, rattled in at 10.34am, with an epicenter almost exactly in the same spot.

The quakes were felt by millions across the area after they hit on Saturday morning.

'I felt shaking early this morning 6-7am, thought to myself in my sleep that it was an earthquake and woke this morning to see the news,' one person wrote on Reddit following Sunday's earthquakes. 

The US Geological Survey has not reported of any damage caused by the five earthquakes.

It is uncommon for residents in northern California to notice the quakes, with the majority ranking as a three-magnitude or less, but some people reported feeling their home shaking from the seismic activity.

The US Geological Survey (USGS) reported that people typically only feel earthquakes that have a magnitude 3.0 or higher but it also depends on the quakes' depth and location.

At their deepest, quakes can begin as far as 400 miles underground.

Earthquakes that reach 43 miles or less are considered shallow and will only result in mild to moderate damage.

However, 2024 has seen a record number of mini-quakes across the state and geophysicists are now warn California could be at risk of a generation-defining massive earthquake.

'2024 has had more earthquakes than any year we've seen since 1988,' Caltech geophysicist Dr Lucy Jones told reporters. 'We should expect this to continue.' 

Experts believe a major quake in Southern California - usually defined as 7.0 and up - could kill at least 1,800,leave 50,000 injured and cause more than $200 billion in damage.

The spate of quakes occurred as a heat come encompassed the state, leaving many people questioning if the record-breaking heatwave was at fault. 

Roughly 25 million residents faced heat alerts this weekend that stretched from California's southern border up to Washington and Idaho, but the USGS assured that it was not to blame. 

'There is no such thing as 'earthquake weather,' the USGS said. 

'Statistically, there is approximately an equal distribution of earthquakes in cold weather, hot weather, rainy weather, etc.'