What is glaciology? ● any of the branches of science dealing with snow or ice ● Land ice vs floating ice (ocean, lakes, rivers) ● Land ice: Glaciers and ice sheets, ice-rich permafrost Water on Earth Freshwater 3% Other 1.2% Glaciers: 1% Greenland Groundwater 11% ~30 % Saline (oceans) Glaciers and Antarctica 97% Icesheets 88% 69-75 % Sealevel equivalent: Antarctica ~57 m; Greenland ~ 7 m; others ~0.5 m National Snow and Ice Data Center Glaciers: Rivers of ice This is boring, show a movie Valley Glacier Ice field (e.g. Bagley) Hanging Glaciers Tidewater Glacier Icefield (Seward) Surge-type Glacier Piedmont Glacier (Malaspina) Space Shuttle Picture Icefall Topography of the Earth at high latitudes, the climate system is at least as effective as plate tectonics in producing high elevation topography, and it does it quicker (both on the way up and the way down) If you take fresh water out of the ocean, you have to pile it up somewhere. That growing or shrinking pile is part of the climate system. What are the feedbacks here? What can make the pile shrink the fastest? Is that going on now? Topography of the Earth at high latitudes, the climate system is at least as effective as plate tectonics in producing high elevation topography, and it does it quicker (both on the way up and the way down) If you take fresh water out of the ocean, you have to pile it up somewhere. That growing or shrinking pile is part of the climate system. What are the feedbacks here? What can make the pile shrink the fastest? Is that going on now? <–1.5 –0.5 –0.2 0 0.2 0.5 m/yr Pritchard et al., 2009, Nature Glaciers 101 Accumulation (more snow than melt) Climate ELA (Equilibrium Line Altitude) Ablation (more melt than snow) Ice flow: interesting physics Cross section of a glacier Medial moraines Lateral Moraines Lateral moraine Medial moraines Barnard Glacier Surface moraine Terminal moraines .