FNR 10300 Lecture Notes - Lecture 29: Continental Crust, Oceanic Crust, Nutrient Pollution
4 Nov 2016
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Document Summary
Marginal cost- cost of taking one more step, or producing one more good or service. Cheapest and most effective way to reduce pollution. E. g. , eliminating lead from gasoline: banned since 1996, widespread and significant decrease in lead in u. s. surface waters. Non-point sources often harder to control than point sources. Huge portion of water pollution: sediment, fertilizers, pesticides. I(cid:373)prove(cid:373)e(cid:374)ts due to : pollution prevention measures, planting of sea grasses and wetlands. Compositional boundaries- based on seismological evidence and experimental data. Lithosphere: 0-100 km depth, mechanically strong and rigid, lithos = stone. Asthenosphere: 100-200 km depth, mechanically weak-partially molten (about 2%, astheno = without strength. Below 200 km- regular solid mantle again. Rock definition- naturally-formed, consolidated material composed of grains of one or more minerals. 5 main characteristics: solid, natural, orderly internal structure, specific chemical composition. These 3 make up over 80% of earth"s crust. Erathquakes, volcanism, or mtn. building = tectonic activity.
