AdvertisementBeneath Alaskan Wildfires, A Hidden Threat: Long-Frozen Carbon's ThawJuly 27, 2015Nathan RottfacebookEmailSome of Alaska's wildfires are dramatic: flames, vast plumes of smoke and firefighting battles. Here, on June 17, a helicopter releases hundreds of gallons of water onto the Stetson Creek Fire near Cooper Landing, Alaska. But even fires that look far quieter, like they're all burned out, can continue to smolder underground — and pose a dangerous threat to permafrost. (AP)