PORTLAND, Ore. (KOIN) — A series of earthquakes rattled southern Oregon overnight on Wednesday, the USGS geological survey shows.
A second quake registered at 4.0 and three others measured at 3.4, 3.4 and 3.2.
The quakes were all relatively shallow, measuring no larger than 6 miles deep.
The largest in a year-long swarm of quakes in northern Nevada near the Oregon boarder struck at 6:52 p.m. Wednesday. At 4.6 magnitude, it’s the largest of nearly 4600 quakes that have shaken this unpopulated area of northern Nevada in the last year.
It’s not the first time swarms of earthquakes have happened in what geologists call the Bald Mountain Earthquake Swarm area
“Sometimes they build up to a 6.5 and other times they go on for a year and then go back to sleep,” Oregon state geologist Ian Madin said. “We really don’t have a solid understanding of why they’re happening.”
But he added there is nothing really to worry about.
“This is really a pretty isolated system.”
Madin said the Bald Mountain quakes southeast of Lakeview are different — in geological terms — than a recent swarm of quakes off the southern Oregon coast.
But the two swarms are alike in that they are not related to the Big Quake.
Recently US Geological Survey Seismologist Seth Moran told KOIN 6 News the big Cascadia Subduction Zone quake would come from a fault line running very close to the coastline. It’s caused mega-quakes in the past and it remains in an eerie sort of silence because geologists think it’s stuck.
“If that entire patch were to go all at once that’s the magnitude 9,” Moran said. “It’s a long fault, it’s a wide fault.”