‘Zombie fire’ in the Arctic revives from the ice

In the frigid Arctic, fires that were extinguished the previous year can flare up again the following spring, known as zombie fires – or zombie fires.
In the frigid Arctic, the fire season usually only begins in June, when the snow has melted and summer storms come. So, scientist Sander Veraverbeke was very confused when he detected signs of many fires on several satellite images obtained from Alaska and the Northwest region of the Arctic in May 2016.

Veraverbeke, an Earth scientist at Vrije University in Amsterdam, the Netherlands, said the satellite had captured images of “zombie fires” – which are remnants of a great fire from the previous year. When people thought they had handled the fire, they still “survived” silently underground for a whole year, waiting through the winter to flare up again. Zombie fires have broken out many times over the past decades and tend to happen more and more often. (Photo: National Geographic) Zombie fires have broken out many times over the past decades and tend to happen more and more often. Mr. Veraverbeke’s team found that their occurrence is strongly linked to climate change. The fact that the summer is getting hotter and longer with a series of large fires increases the rate of spawning zombie fires. The proliferation of these “zombies” shows that the Arctic is changing rapidly under the influence of climate, and is a warning bell for more serious disasters in the future. The fact that the summer is getting hotter and longer with a series of large fires increases the rate of spawning zombie fires. (Image: Getty Images) Hibernation in peat More than 16,187 square kilometers of the Arctic is covered with peat, which stores an estimated 415 billion tons of carbon, equal to the total amount of carbon found in all trees on Earth. As summer approaches, fires formed by lightning strikes or humans will burn directly above the peat above ground. “ These are ancient soils. Peat in Siberia is really very old ,” said Jessica McCarty, an Arctic scientist at the University of Miami, Ohio. Once peat is ignited, they can provide a medium for a fire to smolder underground long after the surface fire is extinguished. Fires sustained by peat can burn for days, weeks, months, even years. When the right time comes, they will once again flare up into great fires, like undead zombies. “ Peat has everything a fire needs to sustain itself. Fires can burn quite strong enough to last through the winter. They’ll essentially ‘hibernate’ until next spring, when the snow melts and gives a chance for fires to flare up in the ground.” , said researcher Rebecca Scholten from VU Amsterdam. Once peat is ignited, they can provide a medium for a long smoldering underground fire. (Photo: Sentinel Hub) What’s different about fire in the Arctic? From 2000 to 2010, fires consumed more than 50% of the Arctic every year. Over the next 10 years, the annual fire area continued to increase, especially in Alaska. Through the data, scientists found that the current frequency of fires in the Arctic is the highest since the first forest formed in this area about 3,000 years ago, maybe even the highest in 10,000 years. by. Wildfires in the Arctic produce more carbon than places like California or Europe, because the subsoil under high-latitude forests is often made up of old, carbon-rich peat. In 2020, the Arctic fires released nearly 250 megatons of carbon dioxide, about half the carbon emitted by humans in a year in Australia and about 2.5 times more than the record-breaking 2020 bushfires. in California. Climate Change Zombie fires have long been known to experts. In 1941, a man-made fire along a railroad in Alaska consumed almost everything within a 1,600 square kilometer radius around it. By May 1942, the fire “revived” and burned about 1,200 square kilometers. But scientists haven’t been able to determine whether these zombie fires are well documented, or if they occur more frequently as the Arctic climate warms rapidly. They think the second case is very likely. “ We’ll definitely see more of them (zombie fires) based on what I’ve seen in 30 years of observation and consultation (other experts) ,” said Randi Jandt, a fire ecologist at the University of Alaska, Fairbanks. Jandt cited the great fire that burned more than 10,000 square kilometers in Alaska in 2019. Fire crews had to work around the clock to prevent the fire from spreading. But when they thought the disaster was over, the fire flared up again the following spring, just as the snow had melted. “ Just now you observe that the area is completely white of snow, but only two days later, the fire suddenly broke out in that very place. ,” said Mark Parrington, a researcher at the Copernicus Atmospheric Monitoring Service, describing the 2020 zombie fire in Alaska. Mr. Parrington said the frequency of fires in recent years in Alaska, Siberia and northern Canada have all increased sharply. “ In the past, firefighting in the Arctic didn’t get much attention because fires were rare, but that’s changing rapidly.” , said researcher Parrington. Wildfires in the Arctic produce more carbon than places like California or Europe. (Photo: Esquire Middle East) Another concern is how many zombie fires are buried underground, waiting to create a new disaster. Scientists say underground fires in the underground peat layer grow very slowly, only about 100 times faster than hair, so the possibility that fires from many years are still accumulating under the ground can be ruled out. land. Therefore, researchers only study fires in the past year. However, the increasing severity of fires shows that climate change is making the situation worse. The hot summer produces large fires that burn until the end of the season, and remnants of those are more likely to last through the winter. In the North West of the Arctic, zombie fires typically flare up every six of the hottest summers. In the summer of the cooler years, no zombie fire will make it through the next winter. “ There is a clear relationship between zombie fires and high temperatures and fire zones. That relationship pattern is only likely to intensify for the worse in the future, as climate change increases the likelihood of fires in the Arctic. “, said scientist Scholten.