Question

What is permafrost?

Answer 1

Permafrost is ground soil, sediment or rock that remains at or below 0°C for at least two consecutive years, forming an underlying, essentially permanent frozen layer beneath the surface in polar and high‑altitude regions; each summer, a shallower “active layer” thaws while the permafrost below stays frozen, which affects drainage, vegetation, and makes the ground soggy or waterlogged in spring.