There has been a spike in seismic activity under Mount St. Helens.
There were around 400 earthquakes since mid-July, according the United States Geological Survey. But most were small and not of concern.
According to seismologists, it’s because of magma flowing through cracks deep underground.
Scientists observed 40 to 50 earthquakes a week between August and September.
To compare, the mountain averaged around 11 quakes a month since it stopped erupting in 2008.