wind landforms where are they commonly found? –deserts & semi-arid environments –coastal...

13
Wind Landforms • Where are they commonly found? – deserts & semi-arid environments – coastal areas

Upload: annabelle-york

Post on 30-Dec-2015

229 views

Category:

Documents


1 download

TRANSCRIPT

Wind Landforms• Where are they commonly found?

– deserts & semi-arid environments

– coastal areas

Wind Landforms• wind erosion

– deflation• particles lifted in air or bounce along ground• ex. desert pavement• ex. depressions in sand dunes

Wind Landforms• wind erosion, cont.

– wind abrasion• impact by wind-blown particles• ex. natural arches

Wind Transportation• larger-sized particles

– tend to bounce along ground

• smaller-sized particles– tend to be air-borne

Wind Transportation• dust storm

– strong winds

– arid locations, severe drought, or fallow fields

– The Dust Bowl• 1930s

Wind as a Source of Energy• requirements

– moderate to strong speeds

– consistent

Wind Deposition• loess

– large deposits of wind-blown silt

– ex. Palouse Hills (WA, ID);

Tunica Hills (LA, MS)

• dunes– composed of sand

Types of Sand Dunes• barchan

– crescent-shaped; points downwind

– arid areas with limited sand supply

Types of Sand Dunes, cont.• Transverse (barchanoid)

– like barchan, but quite numerous• wave-like patterns

– ample sand supply

Types of Sand Dunes, cont.• longitudinal

– ridges & furrows run parallel with prevailing winds

Types of Sand Dunes, cont.• Erosional Example

• parabolic– crescent-shaped; points upwind

– blowout due to deflation

Types of Sand Dunes, cont.• foredunes

– irregularly shaped hills & depressions

– complex of erosional & depositional features

– usually coastal

Finito!