One of 2010′s polar fellows, Benjamin Shaw, originally wrote this post for the NatGeo Newswatch Blog.
Photograph courtesy Benjamin Shaw
By Benjamin Shaw
Scientists hope the planned expansion of a tunnel, excavated deep into frozen Alaskan permafrost, will answer questions about melting in the arctic and reveal evidence of ancient life.
Today, the Cold Regions Research and Engineering Laboratory, or “CRREL tunnel,” is run by the U.S. Army Corps of Engineers. Scientists conducting a variety of research programs use the space as an active underground laboratory.
The current tunnel was excavated just north of Fairbanks, Alaska in the early 1960′s by the U.S. Bureau of Mines. The official reason for construction was to evaluate mining and construction methods in frozen soils. But the dig exposed a treasure of geological formations, animal fossils and ancient plant remains. Bones and teeth of bison, woolly mammoth and horse from 14,000 years ago protrude from the tunnel wall, literally frozen in place and time.
Photograph courtesy Benjamin Shaw
In 1999, NASA astrobiologist Dr. Richard Hoover discovered a new bacteria species in ice samples from the tunnel’s roof. Hoover says the roughly 32,000-year-old microbes suggest similar life forms may exist in the glaciers or permafrost of Mars or in the ice oceans of Jupiter’s moon Europa.
Researchers are now planning an expansion to the tunnel and the U.S. Army Corps of Engineers has received $500,000 in federal funding to begin small-scale engineering tests.
Currently, a small wooden shack juts from the base of a wooded hill. Inside a heavy door, the tunnel cuts one hundred and ten meters in and fifteen meters down through the frozen earth.
A shack sits at the entrance to the tunnel. Photograph courtesy Benjamin Shaw.
Research Physical Scientist Dr. Matthew Sturm lives above the CRREL tunnel and is the resident caretaker and tour guide. The tunnel is chilled to -4 degrees Celsius year round to prevent the permafrost from thawing, and before entering visitors are provided hard hats and parkas. The passageway descends through the permafrost made up of frozen silts, a gravel layer, and then into bedrock.
Hard hats and parkas await visitors to the tunnel. Photograph courtesy Benjamin Shaw.
Permafrost is soil or rock that remains frozen for two or more years. But warming temperatures are causing the permafrost to melt all across the arctic causing environmental changes and engineering headaches.
As permafrost thaws, carbon that had been bound up in the frozen tundra is released into the atmosphere, intensifying climate change. More immediately, warmer temperatures are leading to buckled roads and
cracked building foundations.
Sturm says an expanded tunnel will help answer important questions about thawing permafrost that can’t be seen by looking at the surface. “We have massive circum-arctic lands all of which are undergoing some degradation of permafrost, but we don’t know what’s happening until we see it in the surface evidence.” But the expanded tunnel, says Sturm, will give scientists a unique three-dimensional look at frozen arctic soil.
Excavation on the new tunnel will also focus on preserving DNA materials. “To get the paleontology story right you have to harvest the materials very carefully,” says Sturm. “That was not done in the current tunnel.”
The excavation will add 1000 feet of new tunnel. Sturm hopes drilling for the new tunnel will begin in December of 2011 and open by 2013.
“I’m ecstatic that we’re moving forward,” says Sturm.
Sturm holds a mammoth bone found in the tunnel.
Photograph courtesy Benjamin Shaw.