Chapter 15 Outline

Chapter 15 Outline - Chapter 15: Eolian Processes and Arid...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 15: Eolian Processes and Arid Landscapes Introduction Wind agent of geomorphic change- causes erosion, transportation, deposition of materials; fluid; win processes can modify, move sedmt in deserts, along coastlines in diff climates; can contribute to soil formation/move sedmt in places vry far fr origin, fallow fields (not planted) lose soil to wind erosion Winds can even spread living orgms eg mosses, lichens The Work of Wind Eolian - work of wind- erosion, transportation, deposition; wind’s ability to move materials sml compared to other transporting agents b/c air less dense, but over time, much work done, quickly; grain size impt in wind erosion- medium-sized ones move most easily, lg/sml ones req strongest winds: Sml b/c have mutual cohesiveness, usu present smooth surface (aerodynamic) to wind; wind can prune, shape vegetation esp when winds strong in consistent direction; wind can carry things btwn continents Eolian Erosion Deflation Removal/lifting of loose sedmt; fine materials eroded by wind; leaves behind desert pavement - conc’n of pebbles, gravel eg a cobblestone street, protects underlying sedmt fr more deflation/water erosion; H 2 O impt to its formation: washes away fine materials, conc’s/cements remaining rock pieces Heavy recreational activity hurts fragile desert landscapes, esp in arid lands; eg ORVs, military activity threaten desert life, make sedmt available for deflation; wherever wind meets loose sedmt, deflation may remove enough material to form basins- blowout depressions - range sml indentations to: 100s m wide/many m deep; chem. wthring, tho slow in desert due to lack of water, impt in its formation b/c removes cementing materials tht give particles thr cohesiveness Abrasion Grinding of rock surfaces w/sandblasting action by particles captured in air; rate of abrasion: hardness of surface rocks, wind velocity, wind constancy; abrasive action limited to area immediately above ground b/c sand grains lifted only short distance; abraised rocks look pitted/grooved/polished: Usu aerodynamically shape in certain direction, according to consistent flow of airborne particles carried by prevailing winds; rocks tht show evidence of eolian erosion= ventifacts ; lgr scale: deflation, abrasion can streamline rock structures aligned parallel to most effective wind direction” Causes distinct, elongated ridges/formations- yardangs ; abrasion conc’d on windward end of each yardang, w/deflation working on leeward parts Eolian Transportation Atmos’ic circ can transport fine material eg volc debris worldwide quickly; wind exerts drag/frictional pull on surface particles til they become airborne; distance wind can move suspended particles varies w/particle size; human, natural sand erosion/transport fr beach slowed by ppl’s conservation measures Sand transport problem to human settlement near coastal dunes;
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 06/24/2008 for the course GEOG 1 taught by Professor Okin during the Fall '06 term at UCLA.

Page1 / 3

Chapter 15 Outline - Chapter 15: Eolian Processes and Arid...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online