Landform Formation by Erosion

1. Landform Formation by Erosion

3. Water Cycle = Hydrological Cycle • A series of events where water is stored and/or transferred.

4. Water Storage • Water is stored in lakes, rivers, clouds, snow, and glaciers.

5. Methods of Transfer • Precipitation (rain), rain runoff, condensation, sublimation, evaporation, transpiration, and snowmelt.

6. Weathering • Weathering is the slow breakdown of rock through chemical, biological and physical processes

7. Erosion • The breakdown of rock by wind, gravity, water, and ice Wind • AKA – Aeolian or alluvial Erosion • Causes sand dunes and alluvial fans Gravity • Mass movement of sediment. • Ex. Landslides, mudslides, avalanches

8. Water Erosion • Splash Erosion – caused by raindrops • Sheet Erosion – caused by flat sheets of rain pouring off • Rill Erosion – caused by small narrow areas where rain gathers and drains. • Gully Erosion – water then erodes away larger gullies.

9. Lateral Erosion • Erodes the sediments on the sides of streams. • Meanders are the S shaped bends in a river formed when a river flows over a flat plain. • Rivers deposit sediment on the inside of curves and erode banks on the outside.

10. Vertical Erosion • The downward cutting into bedrock by a stream forming valleys (hilly) and gorges (mountainous).

11. Oxbow Lakes • Sickle shaped lakes that form from meanders. • A meander is cutoff from the river leaving an oxbow lake.

14. River Delta • River deltas are formed by constant deposition of sediment being deposited in the ocean or large lakes in a fan shape.

17. Shoreline Erosion • Caused by the pounding of surf and tidal movements. • Creates crescent shaped beaches.

18. Human Effects • Any process that removes vegetation (ranching and some construction) increases erosion. • Topsoil removal for farming also increases erosion.

19. Erosion in Alaska • Matanuska River • Revegitation and Erosion Control • Shishmaref Village (video)