Multiple earthquakes strike off Oregon coast with the strongest reaching nearly 6

A 5.8-magnitude earthquake struck off the coast of Oregon late Monday, followed by a swarm of smaller quakes that continued into Tuesday.

The US Geological Survey reported the first tremor at 10:30pm local time (1:30am ET), about 102 miles west-southwest of Port Orford.

At least five additional quakes have been recorded in the same area, the strongest measuring 4.9 magnitude.

‘This event is identified as the potential mainshock of an earthquake sequence,’ the USGS said in its notice of the original larger quake. 

The agency estimated a six percent chance that one or more aftershocks stronger than magnitude 5 could strike in the next week, powerful enough to cause damage. 

Smaller tremors are more likely, with as many as 50 aftershocks of magnitude 3 or higher expected, strong enough to be felt in the region. 

The 5.8 magnitude earthquake hit just hours after Oregon Gov. Tina Kotek had mandated that all new state-owned buildings larger than 10,000 square feet meet the highest earthquake safety standards, while older structures must be upgraded to current life-safety codes by 2060.

This is a developing story… More updates to come 

The earthquakes hit about 102 miles off the coast of Port Orford (pictured)