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.

On Tuesday, hundreds of earthquakes were detected, with depths ranging from 1.2 to 3.7 miles below the summit.

MT. RAINIER, Wash. — A swarm of small earthquakes was detected at Mount Rainier Tuesday morning, according to the U.S. Geological Survey Cascades Volcano Observatory (CVO) and the Pacific Northwest ...

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

The U.S. Geological Survey said it and other agencies were monitoring the situation and would issue additional alerts "as needed." ...

Mount Rainier, the active volcano towering above southwestern Washington state, started rumbling — very lightly — on Tuesday.

Hundreds of small earthquakes were detected at Mount Rainier on Tuesday in the largest such swarm at the active stratovolcano ...

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

The quakes began just before 1:30 a.m. on Tuesday, according to the Geological Survey at the Cascade Volcano Observatory.