As of this afternoon, scientists were deciding whether to upgrade their prediction for the severity of the impending Mt. Saint Helens eruption. It’s currently expected to rank a 3, on a scale of 1 to 10.

The 1980 eruption that blew off the top of the mountain was a 5.

You can see the area affected by the 1980 eruption near the center of this map of deforestation in the central Cascades (animation requires Flash). Start the animation, and keep your eye on Mt. Saint Helens near the center of the map. In 1980, a big smudge mars the center of the map; that’s the blast zone of the eruption, an area roughly 150 square miles in size.

What’s most interesting to me is that, as huge and powerful an event as the eruption was, human logging has cumulatively had the far larger effect on the landscape. It seems that—every bit as much as a volcano—we humans are now forces of nature.