Alaska burning: explosion near Eagle leads to mysterious geologic ground craters

December 8, 2012 – ALASKA – Residents in the Yukon River community of Eagle are excited about a mysterious geologic event that is emitting fire, steam and a sulfur smell. Yukon Charley Rivers National Preserve lead Interpretative Ranger Pat Sanders says it all started on Sept. 27. An explosion was heard, in Eagle, which is rare so of course we were interested,” Sanders said. Sanders says on Oct. 10, a fire was spotted about 2 miles up the Tatonduk River, known locally as Sheep Creek. She says the fire spread to about 15 acres. “And on the 15th of October we had snow and the fire was still going although it appeared to be emitting steam and there was a sulfur smell,” Sanders said. No one has been on the ground there yet, but over-flight photographs reveal a slumping area that is steaming and looks a lot like a mini volcano crater. Sanders says the area is about 25 miles Northeast of Eagle and it’s located on Doyon land. She says both NPS and USGS geologists suspect it is a shale oil rock deposit. Sanders says the area has two slumping craters that cover about a five acre area. “It’s been really interesting to watch because it’s still steaming and still burning but if it is indeed oil shale as USGS suspects, oil shale and sulfur, it could be as deep as a thousand feet which means it could have been burning for some time from a lightning strike years ago and it’s been burning underground and finally burned enough to cause a slump or a crater like depression in the earth so until we actually get boots on the ground and we don’t know when that’s going to happen, we’re not going to know,” Sanders said. Sanders says it’s difficult to tell from the hazy aerial pictures, but the craters appear to be as deep as 150 to 200 feet and she says there has been significant slumping since it was first observed. She says the Hard Luck Creek fault is in the area and is an active fault. USGS geologist Marti Miller says it’s more likely to be burning oil shale not a burning coal seam. “But we’re fairly confident that it’s not a hot spring or some other type of volcanic related incident,” Miller said, which will be disappointing news to Pat Sanders in Eagle. “Of course everyone in Eagle is hoping it’s going to be a thermal event and we’ll end up with a hot springs but maybe that’s just because it was 45 below last week,” Sanders said. NPS geologist Linda Stromquist says, although they would like to examine the site sooner, at this point in the year it is probably prudent to wait until better weather and daylight conditions improve, toward spring. –Alaska Public