A permanently frozen layer of earth. It never thaws out.
permafrost
It is known as the permafrost.
permafrost
it is called permafrost
Tundra
permafrost
Tundra
The permanently frozen layer of earth is called 'permafrost'. Please ensure you use a current referent when describing permafrost extent, since permafrost borders are rapidly changing in both directions.
That's called the 'permafrost'.
The best I can tell it's called permafrost
Permafrost.
permafrost