An earthquake with a magnitude of 6.3 was recorded off the coast of Oregon Thursday morning, according to the US Geological Survey.

The quake hit about 180 miles off Coos Bay at about 8 a.m. Pacific time., the USGS reported — the second serious tremor to shake up the northwest this month.

Thursday’s tremor was at a depth of about 7 miles under the ocean, but no tidal surge was reported, KGW8-TV reported Thursday.

Earlier this month a 5.4-magnitude earthquake struck about 260 miles off the Oregon coast.

According to the USGS, the Pacific-Juan de Fuca Plate offshore along the northwest coast periodically experiences moderate earthquakes, with 21 of magnitude 6 or higher over the past 100 years.

The most severe was a 6.9-magnitude tremor in 1991 that was felt as far as northern California.

An Oregon State University study from 2008 indicated that 40 years prior, there had been 1,500 quakes of magnitude 4.0 or more along what is called the Blanco Transform Fault Zone, where Thursday’s temblor took place, KGW8 said.

Earthquakes are measured on the Richter scale, a numerical scale based on seismograph readings.