liustik

Liustik is the Estonian term for a glacier, a large, persistent mass of ice formed from accumulated snowfall that survives year after year and moves slowly under its own weight. Glaciers develop where snowfall exceeds melt over long periods, allowing snow to compact into dense glacial ice through recrystallization. They are commonly found in high mountain regions and polar areas where temperatures remain cold enough to sustain year-round ice.

Glaciers have distinct zones: an accumulation (or upper) zone where snow gains mass, and an ablation (or lower) zone where ice loss occurs. The boundary between these zones is the equilibrium line. Glacial movement occurs through internal deformation of ice and, where meltwater lowers friction at the bed, through basal sliding. Glaciers shape and sculpt landscapes, forming features such as crevasses, seracs, moraines, and fjords, and they transport rock and sediments over large distances.

Types of glaciers include valley (alpine) glaciers, ice caps, ice sheets, piedmont glaciers, and tidewater glaciers. They cover diverse environments, from high mountain ranges to polar regions. Glaciers respond to climate and can advance or retreat with changing snowfall and temperatures; many have retreated in recent decades, contributing to changes in sea level when the ice is land-based.

Liustik play a crucial role in freshwater storage, hydrology, and regional ecosystems. They are studied in glaciology using field observations and remote sensing to monitor mass balance, movement, and impact on landscapes and climate.