Glaciers - Know the different types of glaciers Cirque: small glaciers that occupy cirques (small bowl-shaped depressions at mountain tops) valley: when cirque glaciers flow down valley, sometimes joining together, to form “long” glaciers flowing through valleys. calving: any glacier that flows into a lake or ocean, and breaks off (calves) Into icebergs piedmont: any glacier that flows out of a valley And onto a flat area, allowing the glacier terminus to spread out outlet glacier: valley glaciers that drainice caps or ice sheets Ice field: Like an ice cap, but more nunataks poking through, really a lotof connected cirque and valley glaciers - Know what glacier mass balance means. Accumulation zone: all added mass. Mostly this is winter snowfall that doesn’t melt the following summer. Ablation zone:  all lost mass. Mostly (1) ice melting and (2) calving of icebergs. Equilibrium Line: where they meet- Know warm based versus cold based glaciers, why the difference, and how it relates to water Cold based Glaciers: The bottom of the glacier is below 0 degrees C. No water, no sliding, no erosion, Glacier sides stay in place, middle slides/extends down middle. Warm based Glaciers: contain water at base of glacier. Causes abrasion leading to striation (sliding therefore erosion) ALSO Ifthe scratching agent is fine particles, thenthis leads to glacial polish - Glacier flow – ice deformation and basal sliding, how do these conditions relateto thermal regime (warm vs. cold based). Evidence for sliding? (striations and polish) 1. Internal Deformation: cold based. Move like silly putty (self deforming after time/temp change) glacier develop bands called Ogives= 1 per year 2. Sliding at Base: the base slides on a thin film of water. Sliding causes abrasion which leaves scratches called striations - Know Glacier plumbing: Supraglacial lake: streams flowing underneath a glacier (high pressure→ melting) Moulin: the hole that surface water fallsinto. It is a pipe that carries the water tothe glacier bed. Subglacial streams: - Know a few specific glaciers, Columbia, Grinnell, Jakobshav Columbia: (Alaska) one of the fastest moving glaciers, retreating since 1982, (13 mill tons of ice break off everyday) Chasing Ice movie. Grinnell: (Montana) between 1966-2005 it lost 40% of its acreage. (retreating) Jakobshav: (West Greenland) produces 10% of all greenland icebergs. Studied for over 250 yrs. (The ice stream's speed-up and near-doubling of ice flow from land into the ocean has increased the rate of sea level rise by about 0.06 millimetres (0.0024 in) per year) Fastest flowing glacier in the world. Up to 15 km/yr = 5.6 ft/hourSea Level - Eustatic vs. local sea level change Eustatic: refers to change in global ocean reservoir Local: refers to the sea lvl at any one location - Causes of local sea level change to be different than global sea level change if enough ice melted to increase eustatic sea lvl by 1 ft local sea levels may not feel it instantly, because ocean circulation currents may change, tectonic plates subside etc. - Isostatic uplift, raised beaches, glaciers melting Isostatic uplift: The uplift of Earth’s crust after removal of an ice load. Raised Beaches: are evidence of local sea level rise. Glaciers Melting: - Subsidence, tectonics/earthquakes Subsidence: when soft sand compacts and land falls to lower lvl along with buildings and things on it. Clicker Q: Why are rates of sea levelrise higher in New Orleans? Local effects of subsidence combined with eustatic sea level rise. - History of sea level rise (last ice age, last century) Clicker Q: How much lower was sea level during the last ice age? About 400 feet (120 m) Last century GMSL increased 4-8in - Causes of sea level rise (thermal expansion, glacier melt, ocean currents, floating ice?) Thermal Expansion: when water heats up, it expands. Glacier & Ice Melt: NOT SEA ICE OR GLACIER ICE Ice sheets: Ocean Currents: (& Subsidence) - Predicting the future, RCP scenarios, expected sea level rise 2100 AD RCP Scenarios: “RepresentativeConcentration Pathways” .97 m expected sea level rise in 2100 AD RCP 8.5 - Different countries’ CO2 emissions,rankthe top 5 1. China 2. USA 3. EU 4. India 5. Russia Clicker Q: Where does the US currently rank in terms of CO2 emissions? Number 2, Behind ChinaLocal Impacts - Global warming impacts across US, in Buffalo region/New England Clicker Q: The “polar vortex” is caused by the weakening of the winter jet stream FALSE Global Warming and Politics - Hockey stick controversy The rate of modern warming is unprecedented & Modern warmingreversed natural cooling Clicker Q: Arctic amplification decreases the equator-pole temperature gradient - the “hiatus” in global warming The CRU hack on personal emails of scientists with internal information used to disprove science legitimacy accusing scientists of - examples of tactics used by global warming deniers - Cherry picking information (global 10yr periods of earth cooling that happens) - Geoengineering The deliberate and large-scale intervention in the Earth’s climatic system - solar radiation management vs. CO2 removal, examples of each Solar Radiation Management: Surface-based: Using pale-colored roofing materials to change surface brightness, orgrowing high-albedo crops. Troposphere-based: for example, marinecloud brightening, which would sprayfine sea water to whiten clouds and thus increase cloudreflectivity. Space-based: space sunshade—obstructingsolar radiation with space-based mirrors, dust, etc. NEGATIVES: 1. Expensive! Grandiose! 2. Hard to predict regional changes 3. Doesn’t address other impacts of CO2 CO2 Removal: Carbon capture & storage (store in ground) and create enegry source Carbon air capture: remove CO2 from air then put air back (carbon capture pod, gadget) Carbon Farming: afforestation/reforestation instead of DEforestation, grow a shit ton of trees, they absorb CO2, remove trees so it won’t decay and release CO2 again (problem: forest would need to be gigantic, will take up agriculture space that’s used for food, need to actually grow tons of trees) Ocean Fertilization: including iron fertilization of oceans (problem, with ocean circulation, CO2 could pop back up in