Winter can usually kill most wildfires. But in the far North，some forest fires just don’t die. They are thought of as “zombie (僵尸) fires”.
“Zombie fires” usually sleep underground in winter. Covered by snow, they smoke through the cold. Fueled by carbon-rich peat (泥炭) and soil in the North, most of these hidden fires spread slowly for less than 500 meters during the winter. When spring comes, the flames (火焰) of the fires appear near sites that they burned in winter, and they turn to burning fresh fuels around. This may happen well before the traditional fire season in the far North.
“Zombie fires” had been known mostly from firefighters’ stories. Few scientists studied them until details in some satellite images attracted one research team. Rebecca Scholten, a member of the team, studies earth systems at Vrije University Amsterdam in the Netherlands. Her team noticed an unusual thing. “New fires have been starting very close to the former years’ fires in recent years，and we wonder how often the fires might survive the winter,” Scholten explains.
These “zombie fires” are rarely seen before, according to a new study from Nature. But in recent years, they are becoming more common, the study warns. It is believed that the “zombie fires” are even on the road of being a threat. Forests in the far North are warming faster than the globe’s average (平均数). Scholten says, “We’re seeing more hot summers and more large fires and strong burning. That could set the stage for the fires to become a bigger problem,” she worries. And the region’s soils hold a lot of carbon—maybe twice as much as earth’s atmosphere. More fires here could give off huge amounts of greenhouse gases. That would drive a cycle of more warming and even higher risk of fires.
【小题1】What do we know about the “zombies fires” in the far North?| A．They will completely die out in winter. |
| B．Carbon-rich peat helps them burn slowly in winter. |
| C．They often happen after the traditional fire season. |
| D．Their flames can only appear in spring. |
| A．“Zombie fires” appear earlier than the years before. |
| B．“Zombie fires” happen far from former years’ fires. |
| C．“Zombie fires” happen more frequently than before. |
| D．“Zombie fires” appear in different shapes every year. |
| A．The global warming is slowing down. |
| B．The hot summers are less and less seen. |
| C．The area’s soils are short of carbon. |
| D．More greenhouse gases are given off. |
| A．Where Are “Zombie Fires” From? |
| B．Are “Zombie Fires” Frightening? |
| C．Pay Attention To “Zombie Fires”! |
| D．“Zombie Fires” Are Caused By Humans! |
