noun
- plural of permafrost; layers of soil or rock that remain frozen for at least two consecutive years
Usage: geological term
Examples
- Scientists study permafrosts in Arctic regions to understand climate change.
- The melting of permafrosts releases stored carbon into the atmosphere.
- Construction in areas with permafrosts requires special engineering techniques.
- Permafrosts cover about 24% of the Northern Hemisphere’s land surface.
- Rising temperatures threaten the stability of permafrosts worldwide.
- Buildings can be damaged when permafrosts beneath them begin to thaw.