Volcanologists with Natural Resources Canada (NRC) are monitoring Mount Meager after discovering that the mountain shows signs of low-level volcanic activity.
Located north of Pemberton, the mountain is the site of Canada’s most recent explosive eruption — 2,360 years ago — but there’s currently no cause for alarm, officials say.
“Just the fact that (volcanic activity) was new to us made it worth investigation, since we want to have a clear picture of what the normal background state is — then, if we ever do see signs of unrest, we’ll be able to compare them to the data we already have and understand what has changed and how much,” said Melanie Kelman, a volcanologist with NRC, in an email.
NRC released a situation report that was forwarded to local officials on Sept. 19. The biggest risk to the public right now is on Job Glacier, which has large fumaroles — or volcanic openings that emit steam and hot gases — measuring about 15 to 20 metres deep and 30 by 20 to 30 metres in diameter.
While there is some indication that the fumarole field has been around for the last 40 years, in July a helicopter pilot who is trained as a geologist noticed the fumaroles on the glacier. On top of that, throughout the summer NRC received reports of a sulphuric smell around the valley of Mount Meager, according to the report.
In August, various officials toured the glacier by helicopter and collected data. One important finding: there was no sulphur dioxide or carbon monoxide detected at the scene — which would be an indicator of magma, Kelman said.
There would also be hundreds of small earthquakes before an eruption, she added. Between January 2011 and February 2016, 92 earthquakes with magnitudes varying from one to two were recorded around the mountain, according to the report.
“There is very little seismic activity around Mount Meager right now, and not enough to suggest that there is going to be a volcanic eruption — it takes a lot of work to bring magma to the surface, and this is likely to show up as swarms of hundreds, even thousands of small earthquakes that altogether release a lot of energy,” Kelman said. “We aren’t seeing that… The main hazard at Mount Meager, which we knew about already, is its long history of landslides.”
The mountain, which is home to the popular Meager Creek Hot Springs, experienced a massive landslide in 2010.
Still, NRC recently installed a temporary seismic station — and plans to set up another this fall — to monitor for unrest. In the report, a volcanologist and SFU professor also recommended officials conduct another geochemical survey next spring or summer.
“It’s a fascinating discovery, and certainly reinforces what we knew already from the hot springs and the geothermal studies, that there is heat near the surface at Mount Meager,” Kelman said.