Mannerjäätikkö

Mannerjäätikkö refers to a large, continuous mass of ice that covers a continental area. Unlike smaller glaciers or ice caps, which are typically found in mountainous regions or smaller landmasses, mannerjäätikkö can extend for hundreds or even thousands of kilometers, burying entire landscapes under kilometers of ice. These massive ice sheets are dynamic systems, constantly flowing and shaping the land beneath them through erosion and deposition.

The most prominent examples of mannerjäätikkö today are the Antarctic Ice Sheet and the Greenland Ice Sheet. These ice sheets hold the vast majority of the Earth's freshwater and play a critical role in regulating global climate. Their immense size means that even small changes in their temperature or mass balance can have significant impacts on sea levels worldwide.

The formation of mannerjäätikkö is a slow process that occurs over geological timescales. It requires prolonged periods of cold temperatures and sufficient snowfall to accumulate over many years. As snow piles up, the pressure from the overlying layers compresses the lower snow into ice. Over millennia, this ice thickens and begins to flow under its own weight, often towards the edges of the continent or into the ocean.

During past ice ages, much larger mannerjäätikkö covered significant portions of North America and Eurasia. The retreat of these ice sheets left behind distinctive landforms such as U-shaped valleys, fjords, moraines, and vast outwash plains, which are testaments to their immense power as geological agents.