Permafrost lab enables scientists to track climate change impact
By Linda F. Hersey
Alaska’s permafrost tunnel research facility, run by the U.S. Army Corps of Engineers, remains on the cutting-edge of science and technology more than a half-century after it was established as a natural resource laboratory.
Dug into a large block of permafrost, the U.S. Army Cold Regions Research and Engineering Laboratory is an icy bellwether for climate change in the Arctic region and the impact it has on a warming planet.
“As permafrost thaws around Alaska, we are continuing a series of measurements above the tunnel and at our Farmers Loop site (that are) focused on using remote sensing platforms and ground-based measurements to track permafrost change,” said Tom Douglas, a geochemist and senior science technical manager at the U.S. Army Corps of Engineers.
The tunnel enables climate scientists to study changing ice features in frozen ground in far north latitudes. It also serves for outreach and education, hosting thousands of visitors who see its features firsthand.
Permafrost is earth material that includes bedrock, ice, soil and organic matter that remains frozen for many years. “It’s not just one layer that froze last summer, but it is maintained for multiple years,” Douglas said.
The permafrost tunnel is nature’s classroom, informing scientists, researchers, university students and policymakers. Energy Secretary Jennifer Granholm, accompanied by Sen. Lisa Murkowski, toured the Fox permafrost tunnel in August on her first formal visit to the state.
The site is more than 15 miles north of Fairbanks in Fox, on property that is part of U.S. Army Garrison-Fort Wainwright. The lab’s mission is to provide cold region research and engineering solutions for the nation and the world, as part of its role for the U.S. Army Engineer Research and Development Center.
“The permafrost tunnel is unique, like no other permafrost research facility in the world,” said Gary Larsen, Alaska research operations manager at the U.S. Army Corps of Engineers. “The 1963 tunnel project jump-started a U.S. and international effort to better understand permafrost that has lasted more than five decades.”
Ten years ago, the Army Corps began to expand the permafrost tunnel, in an effort to better understand how permafrost responds to global warming and to support infrastructure development on permafrost.
In 2020, construction crews dug more frozen passageways in the tunnel, in order to expand research capabilities. The project capped a decade-long tunnel expansion project. The tunnel is now a third of a mile long.
The Army Corps plans to add a $5.4 million research building at the site, where a small trailer now sits. The building will serve as a permanent operations area for the Permafrost Tunnel Research Facility and include a sample prep area, cold rooms, lab space, training areas and a network hub for sensors.
The building also will include basic amenities, including a restroom and meeting rooms for the public, that currently are not available.
The capital project is queued up for congressional funding. “We are hopeful construction can start in the next couple years, as we have heard that there is congressional support for the facility,” Larsen said.
Nowhere else on Earth quite like it
The tunnel’s permafrost dates back 45,000 years and reveals the remains of ancient animals that disappeared at the end of the Ice Age, including a woolly mammoth tusk and steppe bison bones, preserved intact and frozen in place.
There are no other permafrost tunnels in the U.S. The Fox tunnel is one of only a few permafrost tunnels in the world and the largest by far.
But the Fox permafrost tunnel is most unusual for its large expanse of permafrost that can be observed from above and from within the permafrost itself. There is nowhere else on earth quite like it. Its features include a variety of unusual ice formations — with names like ice wedges, segregated ice, reticulate chaotic ice and thermokarst cave ice.
Permafrost is structurally important to the soils of Alaska. When permafrost thaws in Alaska, it can cause landslides, soil erosion, lakes to dry up, and saltwater to seep into aquifers and surface waters.
Recent landslides in Denali Park are the result of permafrost thaw. The park service had to close roads in the area this summer because of the risk and damage.
Permafrost that girds the Alaskan ground is hard and has been in a frozen state for thousands of years. But the effects of greenhouse gases are upending that.
Results from recent studies above the tunnel and at sites across Alaska show a dramatic increase in permafrost thaw over the past decade.
In 2020, the National Oceanic and Atmospheric Administration warned that the planet’s permafrost is collapsing. The thaw is freeing bacteria that have been frozen, in a sleep state, for thousands of years. The thaw also releases carbon, which intensifies planet warming.
Mapping ground ice
Climate change and permafrost stability are just part of the diverse research at the site. Studies have included equipment tests by NASA for missions to the frozen Mars environment, as well as research into construction methods in frozen soils and cold region mining techniques.
“Secretary Granholm was briefed on her visit about emerging energy technologies being tested at the site,” Douglas said. “These include solar panel coatings to shed snow and dust, ground source heat pump technology, and using thermosyphons to freeze the ground.”
“We are using geospatial analyses to quantify the different amounts of ice exposures and link them to stocks of carbon and trace metals,” Douglas said. “We also want to develop this technique, so it can be applied to exposures along coastal bluffs or river banks to map permafrost characteristics.”
Electromagnetic induction has been used by mining companies to find subsurface mineral deposits. They use a helicopter to carry a large plastic tube that can look deep into the ground for large features.
“We are trying to use that measurement technique to map frozen (permafrost) versus unfrozen ground. Our instruments are far smaller and look at the shallow subsurface,” Douglas said.
Building on that well-established legacy of research, scientists at the facility say they are excited about finding solutions to climate change and a warming planet.
Researchers at the tunnel facility also are testing electromagnetic frequency instruments and pioneering the use of terrestrial LiDAR to map ground ice. “We found that terrestrial LiDAR works really well to identify massive ice versus frozen silt in the tunnel,” Douglas said.
Terrestrial LiDAR are lasers that allow scientists to map ice at resolutions of less than an inch. It has never been done before, Douglas said.