ENGINEERING INSIGHTS | When the Ground Needs to Stay Frozen
Updated: Aug 25
After spending the last few weeks freezing everyone to death with Antarctic engineering, we thought it was probably time to move on.
We’re not quite ready. But we are heading north.
Permafrost sits beneath around 24% of the exposed land in the Northern Hemisphere, and across Alaska, Canada and other Arctic regions, engineers face a problem that sounds almost backwards: sometimes, the ground beneath a building needs to stay frozen.
Permafrost can contain large amounts of ground ice. While frozen, it can provide stable support for buildings and infrastructure, but once that ice begins to thaw, the ground can settle unevenly. Houses can tilt, roads can crack and foundations can lose the ground conditions they were designed to rely on.
This is not a small problem. A 2025 study mapped infrastructure across 285 Alaskan communities and estimated that damage to buildings and roads associated with future permafrost thaw could cost between US$37 billion and US$51 billion under the scenarios studied.
The engineering response is fascinating because sometimes the building itself is part of the problem. Heat from an occupied building can transfer into the frozen ground below, so structures in Arctic communities are often raised on piles, creating space underneath and reducing that heat transfer.
And when that is not enough, engineers can actually cool the ground.
Thermosyphons are sealed systems that draw heat from the soil and release it into the colder outside air. When conditions are right, evaporation, condensation and gravity keep the process moving without a conventional refrigeration compressor.
They are far from experimental. Thermosyphons have been used in more than 900 installations in Alaska alone, with applications also documented across Canada, Russia and China.
At the Rankin Inlet Air Terminal in Nunavut, a thermosyphon system was installed across the foundation area to help maintain the frozen ground supporting the terminal. On a much larger scale, the Trans Alaska Pipeline stretches roughly 800 miles across Alaska, with around 420 miles constructed above ground. Thermosyphons are used along sections of the route where protecting permafrost is critical to the stability of the infrastructure.
It completely reverses the way we normally think about engineering in cold climates. Inside the building, every effort goes into keeping people warm. Underneath it, the long term stability of the structure can depend on making sure that warmth never reaches the ground.
So yes, we technically left Antarctica.
We just haven’t managed to leave the cold.
NEXT WEEK: Skyscrapers, extreme winds, and why stopping a building from moving isn’t actually the goal. Stay tuned.
Sources: Alaska DOT&PF | US Army CRREL | Prairie Architects | Communications Earth & Environment | U.S. GAO
