Three more earthquakes struck off the Oregon Coast over just a 90-minute span on Sunday night, according to USGS.

it happened between 9:20 and 10:40 p.m., about 250 miles west of Yachats. The quakes ranged in magnitude from 4.2 to 4.8 but there were no reports of damage since they hit out in open water.

Swarm of quakes

However, geologists are very interested in learning why so many quakes are shaking the area over recent months. They're describing it as a significant "swarm" of quakes.

Geologists said the swarm started over two weeks ago and have all been relatively shallow, happening along the plate boundary. They added that the swarm was not related to the Subduction Zone and there have been no reports of damage or injuries.

The Oregon State Geologist told KGW that her office is watching the swarm closely, yet the quakes were not necessarily indicative of any larger things to come.

“They're only occurring six miles deep. That means they're still along the plate here and they're not occurring up here on this plate. That Subduction Zone plate that’s the one we worry about,” State Geologist Vicki McConnell said.

She added that Subduction Zone quakes have much larger magnitudes, can general tsunamis and can cause extensive damage.

Even though they don’t feel there is a threat, scientist said they would continue to monitor the earthquake swarm.