How Glaciers Work Glaciers are thick masses of ice that move slowly over earth's surface. They form on land due to the accumulation of snow in cold climates that are found in mountains at high elevations or at high latitudes. Huge masses of ice found over land masses in polar regions are called ice sheets or continental glaciers . Another large ice sheet covers Greenland.
Smaller glaciers can form at high elevations in low latitudes.
These form at mountain tops and flow down valleys. Therefore they are called valley glaciers or alpine glaciers . Moving glaciers are capable of eroding and transporting huge amounts of sediment. When the glacier moves into warmer areas the ice melts and sediments are deposited. Between the ice ages, warmer global climates resulted in interglacials when ice sheets retreated and alpine glaciers were also much smaller or disappeared altogether.