Officials at the United States Geological Survey have tracked over 300 earthquakes beneath Washington State’s Mt Rainier from July 8-10.
A popular tourist destination, Mt Rainier is also an active volcano, closely watched by experts. On average, the area experiences nine small earthquakes a month. About once a year, activity will increase and become a “swarm.” But these regular annual swarms are not nearly as strong as the current event.
The current swarm kicked off between 1 and 2 in the morning, local time, on July 8. The largest quake came twelve hours later, registering 2.3 on the Richter scale. The strength and frequency of the quakes have steadily decreased since. The Pacific Northwest Seismic Network continues to track the miniature earthquakes.
Much stronger than the 2009 swarm
The 2025 event has far outstripped the most recent big swarm, from 2009. Scientists detected 120 earthquakes in 2009, and the current swarm is approaching 350, at least 55 of which have been over 1.0 magnitude…