Tunnel designed to study permafrost is being expanded
The U.S. Army Corps of Engineers Permafrost Tunnel Research Facility about 16 miles north of Fairbanks is going to expand.
Researchers utilize the facility to study how to better characterize permafrost to understand how to build on it in areas like Fairbanks where there are many roads and homes built on permafrost.
“We have about 300 meters of tunnel right now, and hopefully we’re going to have at least another 100 to 150 meters dug, with the purpose of fully being able to characterize a three dimensional block of permafrost" said Gary Larsen, operations manager for Alaska research office for Cold Regions Research Engineering Laboratory. "Why is that important? That’s important because as we are learning new techniques from drones and other aerial technology to be able to characterize permafrost without having to go and actually dig. This is our ground truth place. If we actually know exactly what’s in the ground here, then this serves as a great ground truth for all those technologies that are being developed now to be able to characterize permafrost. Of course, the better we can characterize permafrost, the cheaper we can do it, the better DOT can build roads, and the better engineers can build and design buildings to work on the changing permafrost environment here in Fairbanks,”
The permafrost tunnel was dug out from 1963-1969 and is a unique research facility to the world. "
The tunnel is important because it’s been taking care of engineering research, and more recently, life into extreme environments (like) paleo research. It’s cool because it also has a bunch of bones, of extinct animals that are sticking out of the walls here up front... and so it’s a really important, really cool resource for the people that live in Fairbanks and around Fairbanks,” said Larsen.
Larsen says the tunnel is in the location that was selected because of gold mining. “We’re out here in the Goldstream valley, and because of the way they mine gold, it left a really nice steep escarpment that was a perfect place to be able to dig a tunnel straight into the hill,” said Larsen.
Although researchers do look into many different areas while utilizing the permafrost tunnel, one focus area is permafrost engineering. “The original research back in the 60’s was about learning about permafrost engineering -- understanding how permafrost acts as an engineering material, and how that contributes to our knowledge that we can then apply to the roads and buildings around Fairbanks. Over the years, the research has morphed into more looking at what happened 10,000 years ago, 15,000 years ago, here in the late Pleistocene... and understanding life in extreme environments. There’s bacteria that’s still alive that’s been frozen for 25,000 years,” said Larsen.
Larsen says this permafrost tunnel is unique to the world. “As far as we know there’s only one tunnel somewhere in Siberia in Yakutsk, but it’s more of a hole underneath a building. This is the only permafrost tunnel specifically set up to support permafrost research in the entire world.”
One of the lessons Larsen says the Permafrost Tunnel demonstrates is how variable permafrost can be. Anything that has been frozen for two years or more is part of permafrost. “That only highlights the challenge to build on it because it’s so different one meter to the next. So if you did a bore hole, you might find an ice wedge, and say ‘oh my gosh this characterizes this whole area’, where really it’s just a small part of it.”
As the permafrost tunnel and expands, a difference can be seen in how each section was dug depending on the era and technology that was used.
The tunnel will be closed to tours for at least four months while the expansion is under way.