More than a dozen small earthquakes rattled the area around Mount St. Helens on Wednesday morning.
A magnitude 3.9 shaker hit east of Spirit Lake just after 12:30 a.m., according to the Pacific Northwest Seismic Network. By 4 a.m. 15 more quakes had struck the area, ranging from magnitude 1.6 to 2.7, KING-5 reported.
There were few reports of damage, according to The Seattle Times.
“It is common to experience swarms of earthquakes at Mount St. Helens,” geologist Trevor Nace wrote for Forbes, adding that the volcano has experienced 40 earthquakes in its vicinity since Monday. “While it is certainly not a sign of an impending eruption, the earthquakes are a result of an active volcanic system.”