Magnitude 3.9 earthquake is ‘unusual’ for area near Mount St. Helens
Jan 4, 2018, 9:59 AM | Updated: 10:37 am
(MyNorthwest)
(MyNorthwest)
Seismologists have recorded more than 80 earthquakes in the past month or so near Mount St. Helens. The average number of earthquakes around the mountain is 17 a month, KIRO 7 reports.
Early Wednesday morning, a magnitude 3.9 earthquake registered just northeast of Mount St. Helens. At least 19 aftershocks followed.
“We have had a lot of small tiny earthquakes in this zone,” UW Seismologist Bill Steele told KIRO 7. “But what we haven’t had is an earthquake this size. A 3.9 is unusual for this area.”
The location of the quake was also unusual, according to Steele. Smaller quakes typically occur on the west side of Mount St. Helens.
The quakes are not believed to be linked to volcanic activity — they are tectonic in nature, caused by the shifting of tectonic plates.
Follow @http://twitter.com/Mynorthwest
