Mount St. Helens Shook by Swarm of Earthquakes, Magma On the Move
Mount St. Helens is keeping up its unsettled 2016, this time with another small earthquake swarm. The USGS detected over 120 earthquakes over the last few days, all occurring 2-4 kilometers (1-2 miles) beneath the volcano and all very small (less than M1). These earthquakes, like the ones that happened earlier this year, are likely caused by magma moving or faults adjusting as pressure changes within the magmatic system underneath Mount St. Helens. It doesn’t change the status of the volcano: It’s active, taking what will likely be a brief rest before its next eruption. That could still be years from now.