California is bracing for a tsunami following a magnitude 7 earthquake off the US state's coast.

A wide-ranging warning has been issued ahead of the wave making landfall - with around 5 million people living in the areas affected.

The earlier quake, which hit at a shallow depth of 10 km, was centered about 39 miles west of the town of Ferndale in northern California, the US Geological Survey said.

The National Tsunami Center has issued a warning spanning much of the US west coast - stretching from Dunes City in Oregon, to San Francisco and San Jose in California, 400 miles away.

Millions live in the warning zone in California's north

California Governor Gavin Newsom is meeting with state emergency officials as the wave approaches

The tsunami is forecast to hit the California coast at 12.10pm Pacific Time - or 8.10pm in the UK.

California Governor Gavin Newsom's team wrote on social media that he "is now meeting with state emergency officials and working to ensure Californians are safe."

The earthquake had initially been designated a 6.6 on the Richter Scale - but has since been upped to a 7.0.