GEG 3102 Lecture Notes - Lecture 10: Ablation Zone, Accumulation Zone, Firn
5 Dec 2016
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Document Summary
Can be a geo-hazard when lots of water is released at once. Liquid water is important to glacial flow dynamics. Melting of glaciers raises the sea level. In the accumulation zone the glacier is gaining mass, and mass is being lost in the ablation zone, with the equilibrium line between the two. Snow ice: weight of the snow leads to compaction which causes an increase in density and a decrease in porosity. Snow firn (snow that has survived a melt cycle) ice (pores are no longer connected [isolated air pockets]) Metamorphism can be dry (no liquid water) or wet (close to 0 , or to the pressure melting point [pmp]) All glaciers contain water, either between crystals of in larger systems. Sources of water (supraglacial): melting, rain, runoff. Most of the water inside the glacier (englacial) comes from the surface of the glacier. Subglacial: from englacial, pressure melting, friction & geothermal heat.
