Permafrost
Context
A thick subsurface layer of soil that remains frozen throughout the year, occurring chiefly in polar regions
Explanation
Permafrost is soil, rock or sediment that is frozen for more than two consecutive years. It exists both on land and beneath the ocean floor.
Applications
Permafrost plays an important role in the Earth's climate as it stores large amounts of carbon.
Thawing permafrost can release greenhouse gases, contributing to global warming.
Permafrost affects infrastructure in cold regions, challenging construction and maintenance.