A monster 7 magnitude earthquake rocked northern California on Friday, triggering a tsunami warning that panicked residents.
The earthquake struck at 10.44am, 45 miles off the coast of Eureka, with an aftershock felt in San Francisco shortly afterwards.
The ensuing tsunami warning was blasted to Californians phones, telling them to seek higher ground immediately.
‘You are in danger!’ it warned.
By 12pm PST, the tsunami warning had been canceled.
But the initial impact rocked households and churned waves in backyard swimming pools.
California is bisected by the San Andreas Fault, the boundary between the Pacific and North American tectonic plates, which is prone to earthquakes.
The tsunami warning was issued for millions of Americans along California’s north coast
Californians were blasted these messages on Friday, sparking mass panic
The 750 mile fault’s northern end terminates offshore near Eureka.
Earthquakes occur along the border between two tectonic plates – such as the San Andreas fault.
Tectonic plates are constantly moving but sometimes they get stuck together by their edges.
Eventually, the stress of the moving plates will unstick them, with the energy released by this unsticking causing earthquakes.
California has long been braced for a historic earthquake locals have nicknamed ‘The Big One.’
Seismologists say the San Andreas fault produces a quake of magnitude 7.8 or above every 150 to 200 years that would occur inland, rather than offshore like Thursday’s tremor.
California was rocked by a devastating 6.9-magnitude tremor dubbed the Loma Prieta earthquake in October 1989 that killed 63, injured more than 3,700 and caused $6 billion worth of damage.
And in April 1906, San Francisco was famously-destroyed by a 7.9-magnitude whose epicenter sat just two miles off the coast of the City by the Bay.
In San Francisco, many rushed into their cars and hit the road. It caused snaking traffic on coastal highways, which only added to the panic.
In Fort Bragg, where the first waves were meant to hit, residents were seen rushing to higher ground, preparing for the onslaught
Groceries were shaken from the shelves of markets throughout northern California when the earthquake hit
The earthquake churned waves in swimming pools across the Bay Area
More than 3,000 people were killed and 80 percent of the city’s buildings were destroyed.
Experts warn the long-feared ‘Big One’ would have an epicenter that sits inland and produce far worse devastation.
Friday’s earthquake caused no such damage.
But the frantic warnings triggered mass panic and evacuations.
In Fort Bragg, where the first waves were meant to hit, residents were seen rushing to higher ground, preparing for the onslaught.
In San Francisco, many rushed into their cars and hit the road. It caused snaking traffic on coastal highways, which only added to the panic.
The National Weather Service cancelled the tsunami warning at around noon local time – ten minutes before the wave was meant to hit San Francisco.
‘For the US West Coast, this is tricky stuff,’ explained Tsunami Warning Coordinator Dave Snider, in an interview with NBC.
‘This is time-based. So we have to get that alert out, and then confirm, yes or no, that something is happening.
‘In this case, thankfully, it looks like a destructive wave is not on the table today.’
The Great California Earthquake of 1906 measured 7.8 magnitude on the Richter scale and killed 3,000 people in San Francisco
