Hundreds of small earthquakes have rattled Mount Rainier this week in the largest swarm of tremors in more than a decade. But experts say there's no need to panic -- at least not yet.
"Currently, there is no indication that the level of earthquake activity is cause for concern," the USGS explained. "Earthquakes are too small to be felt at the surface and will likely continue for several days. There would be no damage caused by such small events."
Swarms are clusters of earthquakes that happen in rapid succession, sometimes just minutes apart.
As of Wednesday morning, over 240 small earthquakes had been detected around Mount Rainier, the largest of which was magnitude 2.3.
"Right now, this swarm is still within what we consider normal background levels of activity at Mount Rainier," the USGS said. "Based on our observations, we think the most likely cause of the earthquakes is water moving around the crust above the magma chamber."
