Attention Hikers: Mount Rainier Is NOT Erupting

Here is a thing a national park tweeted today:

If, like, us, you are nowhere near Mt. Rainier, you probably found this a little confusing, if also a little comforting. After all, many things are currently not happening in the national parks—more than are happening, even. Yellowstone isn’t collapsing into a giant sinkhole; the alligators at Everglades haven’t achieved sentience; El Capitan hasn’t toppled over. Why single this particular non-disaster out?

If you live within sight of Mt. Rainier, however, the National Park Service’s announcement likely came as a relief. In videos posted to social media, an ominous-looking plume is visible over Rainier’s summit, looking for all the world like a column of smoke escaping from the guts of the volcano. It was convincing enough that even some local meteorologists concluded the peak was venting.

If today’s vaporous display made some locals concerned, it’s understandable. Rainier is an active volcano, located on a subduction zone where one part of the earth’s crust sinks beneath another. It last experienced a major eruption about 500 years ago—not long at all, in geologic time. The U.S. Geological Survey considers it a meaningful enough threat that it named the peak one of its 16 Decade Volcanoes, which receive extra study and scrutiny. Besides being a destination for hikers and climbers of all stripes, it sits less than 60 miles as the crow flies from a major city. The idea of it going the way of Mt. St. Helens is, to put it lightly, a little nerve-wracking.

The good news: If it’s going to happen, it won’t be today. According to the National Park Service (and the USGS, which quickly jumped in to back them up), today’s display is a lenticular cloud, a kind of flying-saucer-like cloud that often forms downwind of mountains in stable air. So if you’ve got a Wonderland Trail permit this week, there’s no need to give it up.