Today marks precisely 25 years since the big eruption of Mount St. Helens. The once-symmetrical peak lost 1,300 feet of elevation when the north face of the mountain collapsed and many tons of ash were blown into the sky. The eruption killed 57 people and at least 16 housecats, while it laid waste to 230 square miles and pretty much all of the local wildlife. (There’s a tiny bit of media coverage today: here, here, here, here, and here.)
Two years later, the area became a living laboratory when the President and Congress set aside 110,000 acres as a National Volcanic Monument, where natural processes are left undisturbed. One of the most interesting features of the monument is nature’s ecological restoration (seriously, this is a very cool link for nature-geeks), which is being monitored with great interest by folks who would like to replicate the success in lands damaged by human disturbance. For more on this, check out this fascinating article in the Seattle Times.
Elk and black-tailed deer have returned in numbers, so have bears, coyotes, and even wolverines. But the first above-ground species to re-colonize the blast zone were ballooning spiders who use their webs as hang gliders. In fact, scientists estimate that during the four summer months when they are active, 80 pounds of spiders and other flying insects are deposited on each acre of the monument.
The gradual—but also astonishingly quick—regeneration at Mount St. Helens is exciting to watch. It’s not every day that we get to witness the impacts of the geological forces that shaped the Northwest.
P.S. Here are some cool photos of the mountain, pre-, mid-, and post-eruption, courtesy of the US Geological Survey. Here are links to some others, from the US Forest Service. Also, photo galleries here and here.
