Swarm of nearly 20 earthquakes rattles Mount Rainier in Washington, geologists say
.jpg "View from Tolmie Peak Lookout in Mount Rainier National Park")
A swarm of nearly 20 earthquakes measuring up to 2.5 magnitude rattled Mount Rainier in Washington on Wednesday afternoon, the U.S. Geological Survey reports.
A five-hour series of earthquakes began at 3:13 p.m. at Mount Rainier, the USGS reported. Another singular quake struck Thursday morning.
The 2.5 magnitude quake hit between 0 to 1 kilometers (0.6 miles) below sea level, according to the Pacific Northwest Seismic Network. There have not been any reports of anyone feeling the tremor at the surface.
Swarms of this size occur about once or twice a year at Mount Rainier, the USGS says. The most notable swarm of quakes took place between Sept. 20-22 of 2009, when more than 1,000 were detected, according to the USGS.
Magnitude measures the energy released at the source of the earthquake, the U.S. Geological Survey says. It replaces the old Richter scale.
Quakes between 2.5 and 5.4 magnitude are often felt but rarely cause much damage, according to Michigan Tech.