Northwestern US experiences swarm of 40 earthquakes in 24 hours

Experts said the tremors were not a sign of a larger event

The northwestern region of the United States has experienced a string of earthquakes with more than 40 tremors reported in 24 hours.

The US Geological Survey located the tremors on an active geological fault off the Oregon coast on Tuesday, roughly 200 miles from the town of Newport.

The coastal town, which bore the brunt of the tremors that were felt, was among dozens of places to report the earthquakes.

Reports suggested the tremors ranged from 3.5 to 5.8 in magnitude, and were also felt in Washington state. A number of quakes higher than magnitude 5 were reported on Wednesday.

Experts said the swarm of earthquakes were not a sign of a so-called “big one” that is forecast for the western US at some point in the future, however.

“Today’s quakes can be thought of as something like a main-shock and a swarm of aftershocks,” a seismologist, Lucy Jones, said.

She told CNN that since 1980 there have been more than 133 quakes of magnitude 5 or greater, none of which have been followed by something bigger, or on land.

Although Tuesday’s quakes were widely felt, they were not enough for a tsunami warning.

“You need quite a bit of vertical displacement on the ocean floor to generate a tsunami, and earthquakes along the Blanco fault don’t generate it,” another seismologist, Jochen Braunmiller, said to Science Daily in 2018.

The area where the swarm was focused is called the The Blanco Transform Fault Zone.