SSC MTS EXAM

Detailed explanation-1: -Permafrost is a permanently frozen layer on or under Earth’s surface. It consists of soil, gravel, and sand, usually bound together by ice. Permafrost usually remains at or below 0°C (32ºF) for at least two years. Permafrost can be found on land and below the ocean floor.

Detailed explanation-2: -Permafrost is found in places where the average annual temperature is below about 23°F (-5° C), including most of the Arctic and all of Antarctica. Land with underlying permafrost is called tundra.

Detailed explanation-3: -Permafrost terrain consists of an active layer at the surface that freezes and thaws each year, underlain by perennially frozen ground. The top of permafrost is at the base of the active layer, and the base of permafrost occurs where the ground temperature rises above 0°C at depth (Figure 1).

Detailed explanation-4: -How Does Permafrost Form? Just as a puddle of water freezes on a frigid winter night, water that is trapped in sediment, soil, and the cracks, crevices, and pores of rocks turns to ice when ground temperatures drop below 32°F (0°C).