‘We have to do it when it’s cold’: permafrost tunnel expansion racing clock of warming temperatures
Crews are working to expand the U.S. Army Corps of Engineers Permafrost Tunnel Research Facility in Fox, Alaska.
“We are currently in phase four of the tunnel expansion. The tunnel was constructed in the 1960’s by the U.S Army Corps of Engineers, and we have been expanding it in various phases since 2010. We’re currently in phase four and we plan on digging around 200 feet this phase by the end of March,” said Research Civil Engineer Kevin Bjella.
He says because it is a project of interest to the community, it can get chaotic at times.
“It is of interest to the people of Fox, it is of interest to the scientists and engineers of Fairbanks and Alaska. We have a lot of visitors, so we have to coordinate that, and we’re on a tight schedule because we need to do this when it’s cold. We need cold air to keep the permafrost frozen and we need lots of air to get the diesel exhaust out from the digging equipment. So we really can only dig until the end of March; that’s the latest we’ve ever been able to dig, so we’re a little bit under a time constraint,” said Bjella.
As temperatures start to warm up, Bjella says they might have to rotate their schedule to start earlier in the day and end earlier in the afternoon to dig during cooler temperatures.
Gary Larsen, operations manager for the Alaska research office of the Cold Regions Research and Engineering Laboratory, says the permafrost tunnel is essential to help researchers understand what is happening with the permafrost.
“To be able to understand what has happened in the past is what we are seeing underground in the permafrost tunnel. That is really cool and really informative. On the surface of the tunnel we’re also seeing active changes going because of all the rainfall out here, so as a whole this research facility is really important for us to be able to understand what’s happening to the permafrost in interior Alaska,” said Larsen.
The goal of the expansion is to be able to characterize a three-dimensional 16-acre block of permafrost.
“That’s necessary for us to be able to use it as a ground truth for those kinds of geophysical techniques that characterize permafrost -- mainly [that] permafrost isn’t nearly as homogenous or it’s not all the same. Ice content in permafrost is really important for people who want to build roads or infrastructure, or understand as the permafrost degrades,” said Larsen.
While they have a crew expanding the new part of the tunnel, they also have a crew cleaning out the old tunnel that was constructed in the 1960’s.
“We’re thrilled that we’re being able to clean out the older tunnel and expand the newer tunnel, and we’re going to make it even easier and even more exciting to see a whole lot of new features that folks that have been here before haven’t seen. It is going to really expand our capability for research, and it’s also going to make interpretive tours go a lot easier,” said Bjella.
According to Bjella, there are unique challenges to digging underground compared to above ground. “It’s a confined space, so there’s limited visibility... there’s limited ventilation, so we have to supplement the ventilation... and the communication is very difficult as well,” said Bjella.
He said they had to get special underground radios so they could communicate in the tunnel.
While they are expanding, Bjella says they get excited when they come across features such as grass that is still green or bison bones. “From the paleontological viewpoint, there’s a lot of those around here. So from a science point it’s not too exciting, but we like seeing that. We put them aside and they’ll be cataloged with the University of Alaska Fairbanks,” said Bjella.
Bjella says they are hoping to find something that has not yet been found in the area. “Like say... a woolly rhino, a saber-toothed tiger, or a camel, which all did exist here at one time. It would be really exciting to find something like that,” said Bjella.