PORTLAND, Ore. (KOIN) – More than two dozen small earthquakes were recorded within a 6-hour period on Mount Hood Tuesday. Many occurred within minutes of one another.

According to the Pacific Northwest Seismic Network, the string of earthquakes began with a 3.0-magnitude earthquake at 2:35 p.m. The next largest of the 28 earthquakes recorded on the mountain had a magnitude of 2.6 and was detected a minute after the first at 2:36 p.m. 

These two earthquakes were recorded by the U.S. Geological Survey. However, the other smaller quakes, some of which had magnitudes as low as 0.2, were not recorded by the USGS. 

The first earthquake, with a magnitude of 3.0, originated just south of the Mount Hood summit. The second earthquake was near Timberline Lodge.

The Pacific Northwest Seismic Network has previously called this kind of seismic activity a “Mount Hood earthquake swarm.” 

Small seismic activity on Mt. Hood, a potentially active volcano, is not uncommon. The Pacific Northwest Seismic Network data shows that usually at least one small earthquake is recorded near the mountain every week.