M 3.9 quake is the largest in a Mt. Hood swarm

M 3.9 quake is the largest in a Mt. Hood swarm

June 7, 2021

by Renate Hartog

Mt. Hood in Oregon is experiencing another swarm of mostly small earthquakes on its south flank. The largest, a magnitude 3.9, was felt, but most of the little quakes are much too small to be noticed by people.

The figure below shows the location of the earthquakes in map view. They appear spread out over about a mile but since most of these are tiny, this could be due to us not being able to locate them very precisely.

A map of a recent swarm of earthquakes at Mt. Hood, including a M 3.9.

As with previous swarms in the area, we at the PNSN are paying attention, but there is no reason to expect this swarm to cause volcanic activity.

For more, see this bulletin from the Cascades Volcano Observatory: https://www.usgs.gov/center-news/m39-earthquake-and-swarm-occur-mount-hood-june-5-2021