The UAF-CRREL Permafrost Tunnel, Fox Alaska



The Fox Permafrost tunnel is run by UAF and the Army corps of engineers' Cold Regions Research Labs. Permafrost and frozen ground seriously complicate construction of roads, buildings etc., as evidenced by the fact that the parking lot behind the Geophysical Institute often collapses. Hence UAF's and A.C.E.'s interest in studying it. Here are some surface manifestations of Permafrost, and melting there-of.



Not far inside the tunnel, a 14Ky-old femur sticks out of the wall. The scaffolding lining parts of the tunnel is not confidence-inspiring; nor are the dead bones sticking out of the walls.....



Another, even bigger, ice-age bone, tree root and tundra-plant roots. These are some 20-30 feet below the surface, and date back 15-20 thousand years.



All this ground is frozen; it would be a sloppy mess if it melted.



More ancient tree roots; these are tundra willow roots, which are more like tough bushes than trees. These are the same kind of bushes that have been colonizing Alaska'a north slope due to Arctic climate warming (a term which makes Alaska's congressional reps spontaneously 'bury their heads in the sand'...).



The roots of an ancient tundra layer hanging from the ceiling. All of this organic matter is preserved being frozen in permafrost. If the ground thaws, all this stuff would decay, releasing huge amounts of methane and carbon dioxide, both strong greenhouse gasses.



River rocks and gravel (left) and 'loess' (wind-carried glacial dust), side-by-side in the wall of the tunnel. The gravel fills what once was the bed of a stream that flowed through the loess.



Here an 'ice wedge' cuts across the tunnel. These things can extend tens-of-meters into the ground, and all the way up to the surface, where they typically underlie one form of arctic 'patterned ground'. Patterned  ground also occurs on Mars! Though we are not positive that it arises the same way there as on Earth, the Mars Phoenix lander apparently landed on this kind of terrain.



Here's a picture of it in the tunnel's ceiling. All those fine striations in the ice are places where the ice cracked open, when the surrounding permafrost contracted in the cold of winter. Water fills the cracks in spring, and re-freezes. This is how ice wedges grow.



An ice lens in the wall. This is a branch of an ice wedge that has spread horizontally from the main wedge.