How to resolve AdBlock issue? The 5.6-magnitude quake occurred at 8:57 p.m. Saturday 17 miles southwest of Scotia and 36 miles south of Eureka at a depth of five and a half miles, according to the United States Geological Survey.
As of 2 a.m. Sunday, the survey had received more than 2,500 shake reports, the majority from around the North Coast but also some from Clearlake Oaks and Lakeport, and some from further south in California.
The 5.6-magnitude quake occurred approximately 30 minutes after a 3.3-magnitude quake that the US Geological Survey said also was located 17 miles southwest of Scotia at a depth of five and a half miles.
From 6 to 7:30 a.m. Saturday, nine quakes occurred off the Oregon coast and were centered about 200 miles west of Bandon, the US Geological Survey said.
That cluster of ocean quakes included two magnitude 5.4 quakes, one 5-magnitude quake, and six others measuring between 3.1 and 4.7 on the Richter Scale, based on survey records.
US Geological Survey mapping showed that the Humboldt County quakes appeared to be on the edge of the North American Plate. Most of the Oregon quakes – including the three largest – were in the Blanco Fracture Zone on the Juan De Fuca Plate, with three of the smaller quakes on the other size of the fracture zone on the Pacific Plate.
The Juan De Fuca Plate is moving east-northeast and under the North American continent. The subduction between that plate and the continent has the potential to generate huge earthquakes and tsunamis, according to a 2017 report from UC Santa Barbara.
The report explains that Juan De Fuca plate’s region “represents the single greatest geophysical hazard to the continental United States; quakes centered here could register as hundreds of times more damaging than even a big temblor on the San Andreas Fault.”
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