SEATTLE (CBS) – In late November, four swarms of more than 120 earthquakes shook Mount St. Helens in less than a week, The Seattle Times reports.
The quakes were 1 to 2 miles below the surface and too small to be felt, even if you were standing over the epicenter. The activity leads scientists to believe the volcano is likely recharging.
Similar seismic activity occurred during recharge periods between 1986 and the 2004 eruption. The activity is giving scientists a clearer picture of what’s happening, but doesn’t exactly indicate when the next eruption will be.
For now, scientists know the active Mount St. Helens is repressurizing, and it’s not a matter of if, but when.