The Permafrost Tunnel
It's not everyday you get to experience permafrost from the inside. Our group of PolarTREC teachers took a field trip out to the US Army Cold Regions Research and Engineering permafrost tunnels today. These tunnels were made soon after major gold dredging operations ended in the area. This made it much easier to access the actual permafrost (since the several meters of organic matter had been wiped away by powerful streams of water).
Upon entering the tunnel we immediately noticed a nasty smell. The would be the remaining organic matter in the soil. The tunnel is literally a tunnel through time - you pass from about 12,000 years ago (near the entrance) to about 50,000 years ago (in the rear portions about 100 meters back). The first 20 meters or so had ancient roots, rocks, and bones protruding from the walls. We saw a the head of a mammoth's femur, the metatarsal of a horse, and the horn from a steppe bison. How cool is that?
Steppe bison horn
The horn of a steppe bison protruding from the wall of the CRREL permafrost tunnel.
Foot bone of a horse.
A foot bone from a small horse sticking out of the wall of the CRREL permafrost tunnel.
Here's a video of our guide, Pat Druckenmiller, talking to us about the tunnel.
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Further back we encountered ice lenses. I'll let Pat tell you what they are and how they form.
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And here is a picture of one:
Ice wedge in the ceiling of the CRREL permafrost tunnel.
It's weird to see bones and smell smells that originated during the last ice age.
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