Is there a fumarole on Black Tusk? That has been the question swirling since a GeologyHub YouTube video was posted last week that suggested one had been spotted on Sept. 2.
A fumarole is an opening in the earth’s surface that emits steam and volcanic gas, according to the U.S. Geological Survey.
"They can occur as holes, cracks, or fissures near active volcanoes or in areas where magma has risen into the earth’s crust without erupting."
Black Tusk, near Squamish, is one of the mountains in the Garibaldi Ranges of the Coast Mountains.
The supposed fumarole was spotted on the northeast shoulder of Black Tusk.
However, Melanie Kelman, a volcanologist at the Geological Survey of Canada, told The Squamish Chief that it was not a fumarole.
A pilot at Whistler’s No Limits Helicopter Adventures, Denis Vincent, flew out to the area late last week and shot a video that was shared with volcanologists, including Kelman.
"Several of my volcanologist colleagues and I have viewed Denis’s video from [Thursday], which shows nothing unusual happening at the site, just a rock cliff and slope of rocky debris, and the original video — that apparently showed the fumarole — and we think the phenomenon was wind blowing dusty debris up along the slope, possibly after a recent rockfall," she said.
How to tell?
Kelman told The Squamish Chief that if it were a fumarole, one could expect to see signs of it at multiple different times.
"The original video was quite interesting and looked like it could possibly be a fumarole, though I had also seen rockfall dust plumes that looked similar. However, since there had never been a fumarole reported in that area before — and it has a fair amount of air traffic and hikers — we were a bit skeptical," she said.
Vincent's latest video was quite long and showed no sign of any fumarole.
The Squamish resident told The Squamish Chief that he had flown over the area many times recently — including on Wednesday and Thursday last week — and had not noticed anything unusual.
"With something like this, when you see a one-time video, it’s tough to know what you’re looking at. I think you just have to keep looking for changes over time. And since this is a region of dormant volcanoes, we’re interested in anything new or different," Kelman said.
Vincent said he plans to keep flying over the spot, “paying special attention” to check things out.
Please note that this story has been modified since it was first posted to clarify that the GeologyHub YouTube video posted on Sept. 7, was of the sighting, which happened on Sept. 2. We have also corrected one of Kelman's quotes as she misspoke about the day of Vincent's flight, which was last Thursday, not Friday as she originally said.