Mysterious Smoldering Mountaintop in Mideastern Alaska

[Howard]

Residents of Eagle, Alaska, are getting worried about possibly toxic gases wafting into town from a mysterious underground fire on a nearby mountain that's been burning for almost a year.

Nobody seems to know exactly what's burning. Experts suspect it's either a volcano forming or natural gas or oil burning in underground shale deposits. Whatever it is, the fire has been burning on a remote mountaintop, about 40 kilometres north of the community since last October at least.

When the wind is right, residents can smell noxious smoke all over town.

Pat Sanders, a ranger who works in the in the Yukon-Charley Rivers National Preserve, said measurements have been taken showing there's extreme heat coming out of fissures in the ground.

"It's 285 degrees Celcius and that one wasn't even smoking," Sanders said. "There's a lot of heat involved and it's still very, very active and we don't know what it's going to do or how far it extends but we've taken a progression of pictures throughout since October of last year and the changes in the landscape are just dramatic."

Environmental protection agencies have promised air monitors for people in Eagle. They say the sulphur dioxide gases that drift into town are raising health concerns.

Sanders said the fire started with an underground explosion last fall but the effects are visible on the surface. The fire zone used to cover about 5 acres, but it's grown to about 30 after burning all year, Sanders says.

"There's huge orange rocks steaming and smoking and some yellow sulphur rock. It actually looks like a bomb has gone off somewhere."

Aerial photos suggest a volcano forming but geologists say it's likely an underground shale gas fire. Sanders said the air monitors will be welcome, although there's no indication when they might be coming.

"We're happy for that because we don't know how much sulphur dioxide on windy days we are actually breathing".

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One late September day in 2012, Pat Sanders, lead interpretive ranger at Yukon-Charley Rivers National Preserve in Interior Alaska, heard an explosion in the distance.

“I wrote by email to a resident that lives downriver, asking if she was okay,” Sanders recalled. “And she responded with, ‘No, we’re all dead -- why?’”

The neighbor might have been kidding around, but the cause of the explosion may turn out to be no laughing matter. A couple of weeks later, a fire was spotted about 25 miles northeast of the community of Eagle, a town of less than 100 accessible by road only during the summer months. After the first snow, an overflight of the fire revealed a smoldering patch of earth atop a peak, a growing caldera of unknown origin burning away, a jagged, black pit amid the pristine white snowfall.

That was Oct. 15, 2012, and it’s been burning ever since.

“It looks like a warzone,” Sanders said.

People in Eagle began to smell sulfur. The mysterious fire burning in the distance began to worry them. Officials started looking into it, dubbing it the Tatonduk slump and fire, or, alternately, the Windfall Mountain Fire. They determined the likeliest cause was an oil shale deposit under the mountain that had somehow ignited and was now burning steadily, growing as edges of the caldera collapsed into the black pit below.

Sources

http://www.cbc.ca/news/world/story/2013/08/28/north-yukon-fire.html
http://www.alaskadispatch.com/article/20130818/underground-fire-bur...

[Howard]

Smoking Alaskan Mountain Continues to Baffle Residents, Scientists (Oct 11) 

(Courtesy of Derrick Johnson) 

A smoking mountain near the Yukon River not far from Eagle is, after 2 years of study, still a puzzle.

People first noticed acrid smoke in late August 2012. The mountain has been steaming ever since, even during the coldest days of winter.

Linda Stromquist, a geologist for the National Park Service, has been trying to untangle the mystery of the Windfall Mountain Fire that burns above the Tatonduk River. She is one of few people to set foot on the warm flank of the mountain.

Windfall Mountain is not feeding a coal seam fire, common throughout the world and recorded in Healy and a few other spots in Alaska. Coal can burst into flames with nothing more than the heat of the sun.

Samples Stromquist plucked during her visit to the mountain haven't helped explain the fire.

"Why is it continuing to burn when our samples show not-remarkable levels of organic carbon [like coal and peat]?" Stromquist said. "And there's no obvious combustion mechanism, either."

Anupma Prakash is an expert on coal fires who has studied them around the world, including Healy. Interested in the Windfall Mountain Fire, the professor at UAF’s Geophysical Institute encouraged graduate student Christine Waigl and undergraduate intern Kristen Stilson to review satellite images of Windfall Mountain. They found that during the five years before the fire, the mountain had higher temperatures than the surrounding hills and boreal forest

Source