During the Pleistocene Epoch, these covered 30 percent of the world‟s land area.
Fluctuations in these landmasses have been caused in part by periodic changes in heat received by the Sun.  During the Pleistocene Epoch, these covered 30 percent of the world‟s land area. They primarily erode the terrain  through abrasion and plucking, and fields of drumlins and eskers are formed by these entities. Apart from the  oceans, they are the largest reservoir of total water and store about three- fourths of all fresh water in the world.  Arêtes, horns, cirques, and moraines are also shaped by these landmasses. FTP, name these perennial masses of ice  which move over land.
Fluctuations in these landmasses have been caused in part by periodic changes in heat received by the Sun.  
glaciers