On “Un” Frozen Ground
Thawing ground, or permafrost, is a potential troublemaker throughout the Arctic.
Permafrost is mostly frozen water in which ice crystals help bind it together. When the ice melts, the ground collapses.
Until recently, permafrost has been solid enough to support houses, highways, pipelines, and airfields. But rising temperatures have melted the frozen soil’s upper portion, compromising its capacity to bear weight.
- Melting permafrost causes roads to heave, increasing maintenance costs. In Alaska, replacing 1 km (.6 mi) of road can cost up to $1.5 million.
- Photo © Bee Wuethrich
- An Alaskan homeowner builds a new house to replace the one claimed by melting permafrost. The air space under the new house will help keep the permafrost from melting.
- Photo © Bee Wuethrich