A shallow 6.3 earthquake was felt along the Oregon Coast at 8:07 a.m. Thursday but the United States Geological Survey (USGS) says not to worry due to the type of quake it was and where it happened.
“It was a strike-slip event,” USGS Geophysicist Julie Dutton said. “The two plates were moving adjacent to each other. Because of this type of event, you don’t have the displacement of water so you’re not going to have a tsunami.”
The tremor struck approximately 200 miles off the Oregon Coast on the Blanco Fracture Zone, a transform fault marking the boundary between the Pacific Plate to the southwest and the Juan de Fuca Plate to the northeast.
“Even though 6.3 is a large earthquake, it doesn’t have the size to generate a tsunami,” Dutton said.
The Juan de Fuca plate ultimately subducts beneath North America along the Cascadia subduction zone about 124 miles east of Thursday’s earthquake. At this location, the Juan de Fuca Plate slides past the Pacific Plate at a rate of 1.929 inches a year.
The earthquake did not occur on the subduction zone and is the result of Pacific Juan de Fuca plate boundary interactions farther west.
One year prior to this earthquake, a similar earthquake in size, location, and mechanism, occurred on Aug. 22, 2018 and was felt along the Oregon Coast.
More information from USGS:
Strike-slip faults are vertical (or nearly vertical) fractures where the blocks have mostly moved horizontally. If the block opposite an observer looking across the fault moves to the right, the slip style is termed right lateral; if the block moves to the left, the motion is termed left lateral.