Mount Rainier was experiencing "the most significant seismic activity" at the volcano in more than 15 years as an "earthquake ...

Swarms — or clusters of earthquakes that occur in the same area in quick succession — are relatively common on Mount Rainier.

More than 400 earthquakes rattled Washington's Mount Rainier over just 12 hours on Tuesday, sparking fears that the ...

Hundreds of small earthquakes rattled one of the most dangerous volcanos in the US Tuesday, setting off fears it could be ...