More than 300 earthquakes have erupted at Washington's Mount Rainier this week, the largest earthquake swarm at the volcano since 2009.

Mount Rainier is an active stratovolcano 45 miles southeast of Tacoma and 60 miles south-southeast of Seattle. Its last eruption was "a light dusting of ash" in 1894, the USGS said in a report. Large eruptions haven't occurred for more than 1,000 years.

One of the most famous mountains in Washington, Mount Rainier, has been rumbling over the last day due to the amplified seismic activity.