Scientists are monitoring a swarm of 62 earthquakes on Mount Hood in the past 24 hours.
The series of minor tremors began about 6 p.m. Sunday, May 15, 2016.
The 62 minor earthquakes, clustered in Mount Hood Village, started about 6 p.m. Sunday, May 15, 2016.
Although swarms are pretty common around here, this is the biggest one in Hood for a few years. On average, 0 to 3 earthquakes within 10 km of the volcano are recorded each week.
Officials say the tremors have been occurring along a fault three miles deep on the south of the volcano.
Although the cause of this swarm is still unknown, a series of earthquakes tends to happen on volcanoes as magma and gases navigate beneath the surface.
Mount Hood is a potentially active volcano, the highest peak in Oregon State and sits 75 km ESE of Portland in the Cascade Volcanic Arc of northern Oregon.
In the last 1,500 years, Mount Hood has had two major eruptive periods that produced lava domes, pyroclastic flows and mud flows, and minor ash fallout. The most recent major eruptive period began in 1780 and lasted for one to two decades.
And all the Cascade volcanoes seem to be very active… Mount St. Helens was recently hit by about 130 tremors in a matter of weeks.