GEOL 21062 Lecture Notes - Lecture 14: Allegheny Plateau, Sediment Transport, Birch Creek, Alaska
31 Jan 2020
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Document Summary
After our discussions of large-scale topography, how we represent topography in maps, and how topography interacts with geologic structures, you should be frothing at the mouth with curiosity about how topography forms. We now begin our all-too-brief tour of surface processes, in which we will review the main mechanisms that shape topography: why are rivers important, rivers are everywhere [ppt: allegheny plateau dem] Most continental landscapes are the product of river erosion and sediment transport. Even form on other planets & moons: networks on mars & titan [ppt: mars, then titan, long, sinuous lava flows on moon, venus, io. Clearly this is a universal geologic process: rivers are responsible for most of the mass fluxes across the continents. Water, rock (as solid particles or in solution), nutrients. Distribution: fraction of earth"s water that is fresh (non-saline): 3%, of freshwater, ~1/3 is groundwater, 2/3 is ice. Only 0. 3% is surface water, and most of this is in lakes.
