EVERYDAY SCIENCE

Detailed explanation-1: -If you dig down through the arctic tundra, you’ll soon strike a rock-like layer of frozen soil. Even on the warmest summer day, this permafrost layer lies anywhere from a few inches to a few feet below the tundra surface, never thawing. About 85% of Alaska’s land area is underlain by permafrost.

Detailed explanation-2: -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-3: -Permafrost is formed from ice holding various types of soil, sand, and rock in combination. Permafrost contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide, making tundra soil a carbon sink.

Detailed explanation-4: -The temperatures are so cold that there is a layer of permanently frozen ground below the surface, called permafrost. This permafrost is a defining characteristic of the tundra biome.