The term ICE RIVER is composed of two words, GLACIER and ICE. A GLACIER is a large mass of ICE that moves slowly down a slope or valley due to gravity. Glaciers form when snow accumulates over time and compresses into large, thick masses of ICE. Glaciers are found in many parts of the world, including the Arctic and Antarctic regions, as well as mountain ranges such as the Alps and Himalayas. ICE rivers are formed when a GLACIER melts and the water flows downhill. The water from the melting GLACIER forms a river of ICE, which can be seen in many places around the world.