Mount Rainier is a scenic jewel of a mountain in Washington state. It’s also an active stratovolcano that the United States Geological Survey says has a “very high” threat potential. So you can see why a white streamer emanating from the top might make observers wonder if it was about to blow its top. But everything’s cool with Mount Rainier right now.
The worry seems to have stemmed from a tweet on Wednesday by Seattle news meteorologist Kristin Clark who said the mountain appeared to be venting. A video showed a white steamlike plume emanating from the peak and lengthening. Clark put out a call to the National Park Service to chime in on what was happening.
The NPS responded on Twitter, saying “Mount Rainier is not erupting — the sort of behavior seen in this video is not unusual.” The USGS also chimed in, noting the plume was actually a cloud.
According to the USGS, Mount Rainier hasn’t had a significant eruption in the last 500 years, but it’s “potentially the most dangerous volcano in the Cascade Range because of its great height, frequent earthquakes, active hydrothermal system, and extensive glacier mantle.”
There was enough concern over the cloud to prompt the NPS to release a statement with more details. The formation is a lenticular cloud created by moist air pushing over the top of the mountain, likely connected to a weather front. The mountain is closely monitored for seismic activity and there have been no signs of the volcano waking from its slumber.
This isn’t the first cloud to be mistaken for a potential volcanic eruption. In 2018, there was speculation that a long plume spotted on Mars was a sign of the red planet’s Arsia Mons volcano (which was last active 50 million years ago) erupting. But that, too, turned out to be a cloud.
Mount Rainier’s cloud hat might’ve given some folks a small fright, but all is quiet on the range, for now.