A major earthquake hit Alaska on Thursday, with thousands of people feeling shaking near one of the state's largest cities.

The 6.0 magnitude quake was detected around 8:11am local time (12:11pm ET), with Susitna as the epicenter, about 30 miles from Anchorage, which is home to 300,000 Americans.

More than 6,000 people have issued reports of shaking to the US Geological Service (USGS), and the number of reports continues to climb.

There were no immediate reports of major damage or injuries. Authorities are currently assessing the impact.

No tsunami is expected, the National Tsunami Center said. 

One local posted on X saying: 'That was a solid shake.' While others in the area said it 'felt like a couple of dozen jolts' at once.

A 3.3 magnitude earthquake hit in the same area shortly after the major seismic event.

The USGS has warned that there is a 77 percent chance of a magnitude 4 or higher tremor hitting in the next week, with a small six percent chance of another magnitude 6 in the same time frame.

Anchorage reported moderate shaking from the earthquake. 

Light shaking was reported hundreds of miles south of the epicenter of the quake in southern Alaska, according to USGS shake reports.

The last time an earthquake of this magnitude struck south-central Alaska was a magnitude 6.1 that hit 100 miles northeast of Anchorage on May 31, 2021, according to the USGS. 

The Alaska Earthquake Center said on X: 'We have reviewed a magnitude 6.0 event that occurred at 08:11 AM AK time, northwest of Anchorage and at 43 miles depth.

'This event was felt widely throughout south-central Alaska, and as far as Fairbanks.' 

The Susitna region of Alaska sits within one of the most active seismic zones in the world, positioned near the boundary where the Pacific Plate dives beneath the North American Plate, a subduction process that builds immense underground pressure until it releases in powerful seismic events. 

The area is also influenced by the Denali Fault system, a major strike-slip fault capable of producing large earthquakes that can transmit strong shaking across Southcentral Alaska. 

Ongoing tectonic compression creates additional, smaller faults throughout the region, any of which can generate damaging shallow quakes.

Because these forces operate continuously and the region has a long history of significant seismic activity, experts say large earthquakes in and around Susitna are not just possible but inevitable over longer geological timescales.