If annual snowfall is greater than annual snowmelt, then snow will become deeper. Deeper snow will become ice.
Ice can flow.
In the past, glaciers were once more extensive. The glacier acts like a conveyor belt. A mountain eroded by glaciers on several sides will have a pyramidal peak or horn, surrounded by cirques separated by aretes. Drumlins streamlined hills finger lakes Deposition Terminal moraines, ground moraine Kettles, eskers Glacio-fluvial processes downstream from melting glacier Denudation and isostasy The overall sum of erosion from a continent is denudation. A simple model of denudation begins with uplift over a short period of time.