An Alaskan tunnel yields clues to Earth’s fragile permafrost

The World
A view of the permafrost tunnel near Fairbanks, Alaska. The tunnel preserves an environment more than 40,000 years old for scientists and engineers to study.

Time travel in science fiction novels is tricky if not completely unpredictable. But it is possible to at least peer into the past as some climate scientists in Alaska are doing.

Scientists are actively trying to understand what's happening to the Earth's permafrost, the frozen layer of organic material that covers much of the northern reaches of the planet.

So scientists in Alaska with the Army Corps of Engineers have dug a tunnel through some 40,000 years’ worth of permafrost.  The US Army’s Cold Regions Research and Engineering Laboratory maintains the research facility near Fairbanks, Alaska. It’s known as the Permafrost Tunnel.

“The Permafrost Tunnel takes us back in time from about 10,000 years ago here at the entrance where you see a number of prehistoric fossils all the way farther back into the hillside to about 40,000 years ago,” says Gary Larson with the US Army Corps of Engineers. Pointing to the fossilized bones that stick out of the walls in some places, he says that during the last glaciation period, “we had things like steppe Pleistocene bison which are now extinct, mastodons, and those bones are still sticking out of the walls.”

The Permafrost Tunnel was excavated by the US Army Corps of Engineers to study permafrost, geology, ice science, and the mining techniques related to permafrost environments.
The Permafrost Tunnel was excavated by the US Army Corps of Engineers to study permafrost, geology, ice science, and the mining techniques related to permafrost environments. Courtesy U.S. Army Corps of Engineers, Alaska
“Scientists are increasingly concerned about the permafrost thawing out and in a warming world they feel this is likely to happen,” says BBC environment reporter Matt McGrath.

There is an important connection between the permafrost melting and the earth as a whole. Permafrost contains millions of tons of greenhouse gases. So as the world warms up, there are worries that this frozen layer of the earth will thaw out, releasing methane and carbon into the atmosphere and rapidly intensifying climate change.

McGrath says some climate scientists now estimate that “there’s double the amount of carbon that’s actually in the atmosphere right now in the permafrost, and if that starts to thaw out and leak into the atmosphere, it will be almost impossible to stop.”

That’s makes the permafrost tunnel in Alaska invaluable to scientists and climate researchers trying to understand how the frozen permafrost environment has changed, and how it could change radically or disappear in coming decades.

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