A magnitude 4.2 earthquake has struck the Pacific Northwest, just miles from Seattle, Washington.

According to the US Geological Survey, the quake struck 5.05pm ET on Tuesday, approximately 22 miles from the city of 784,000 people.

In the first hour after the seismic event, more than 5,000 people reported feeling the quake around the Puget Sound area, which includes Seattle, Tacoma and the state capital of Olympia.

No injuries or damaged buildings have been reported at this time, and the vast majority of reports have described the shaking as weak to light.

USGS noted that there was about a one-in-four chance of an aftershock stronger than magnitude 3.0 in the next day.

While small earthquakes take place all the time in the Puget Sound area, seismic events stronger than magnitude 4.0 typically only happen every three years on average.

The last major earthquake in the region was the magnitude 6.8 Nisqually quake in 2001, which injured hundreds and caused billions of dollars in damage.

The epicenter of Tuesday’s quake was also near the Cascadia Subduction Zone, a major fault capable of producing powerful earthquakes and tsunamis that scientists fear may be overdue for a major rupture.

The fault marks the point where the Juan de Fuca Plate pushes beneath the North American Plate.

This fault system produces frequent small offshore tremors, but also carries the risk of massive, destructive earthquakes.

Scientists have long warned that the zone is overdue for a catastrophic event, with many nicknaming it the ‘Sleeping Giant.’

The fault is believed to be capable of a magnitude 9.0 earthquake that would impact most of the US West Coast, including major cities such as Seattle and Portland.

The Cascadia Subduction Zone has historically produced quakes of magnitude 8.0 or larger every 400 to 600 years, with the last one striking in 1700.

Predictions of what might happen if a similar quake struck the CSZ today have suggested it could be the worst natural disaster in the history of North America.

Projections warn that thousands of landslides could strike, with 7,000 road bridges collapsing.

FEMA, the natural disaster agency, calculates that 85 percent of ports and drinking water plants would be seriously damaged or destroyed, as well as 77 percent of the region’s airports, railways, schools and hospitals.