Other Classifications By Thermal State
Temperate Glacier: A glacier, whose ice remains near the melting point all through the year. The temperature of the ice is equal from the base layer to the top layers. Their temperature remains between zero degrees celsius to 4 degree celsius. Glaciers of North America, South America, Europe, Asia, Africa, islands of Irian Jaya, and New Zealand are examples of temperate glaciers. The ice remains near the melting point throughout the year. On little increase in the temperature, the ice melts and flows downstream, and adds to the river waters. The rivers of these areas are totally dependent on the molten water of these glaciers.
Polar Glacier: Water starts freezing below 4 degrees celsius, and at zero degrees centigrade, it completely gets frozen. Some of the glaciers on the planet remain below the freezing point (below zero centigrade). All the glaciers of the polar regions remain below the freezing point. The bed of the ice is very thick and hard, however, due to seasonal impact, the ice of the upper layers melts to a limited extent.
Sub-polar Glacier: The region of the sub-polar area contains both the glaciers of frozen as well as the temperate state. These glaciers are also known as polythermal glaciers. The complete bed of the ice remains frozen all through the year in the glaciers nearby the polar regions, while those which are far from the pole, are half frozen and half molten. The seasonal change largely influences their state.
Cold-based Glacier: This ice at the ice-ground interface of a cold-based glacier is below freezing. These are found in higher latitudes and have less seasonal variation in temperature than those found in the lower latitudes. Meltwater is far less a presence. These glaciers still move but due to internal deformation/flow rather than basal slippage.
Warm-based Glacier: The ice at the ice-ground interface of a warm-based glacier is above or at freezing, and able to slide at this contact. Antarctic ice sheets are examples of warm-based glaciers. Slow ice flow occurs in the Antarctic Ice Sheet via a number of ice streams.
Polythermal Glacier: Glaciers with both cold-based and warm-based properties are called polythermal glaciers. The Antarctic Ice Sheet has a number of polythermal glacier type. Up to 55% of the grounded ice sheet may be underlain by ice at the pressure melting point. Wet-based areas include ice streams, outlet glaciers, and regions underlain by subglacial lakes. On James Ross Island, NE Antarctic Peninsula, most of the small outlet glaciers are polythermal, with smaller niche glaciers being cold-based.