Snow accumulating over many years without melting eventually compacts into glacial ice. Types of glaciers: Alpine glaciers or valley glaciers - small glaciers in mountainous areas such as the Alps and the Rocky Mountains Ice sheets - huge sheets of ice covering large areas of land such as the ice sheets on Antarctica and Greenland.
(huge sheets of ice; covering; large areas of land such as the ice sheets on Antarctica and Greenland) (Snow; accumulating; T:over many years) Context(Snow accumulating,List([0, 17))):(Snow; accumulating without melting; eventually compacts; into glacial ice)
Snow accumulating,List([0, 17))
huge sheets of ice Snow Snow
covering accumulating accumulating without melting
large areas of land such as the ice sheets on Antarctica and Greenland
T:over many years
eventually compacts into glacial ice