Wind Erosion & Deposition Earth & Space Science Hutto HS CBFrazier 2016-17

Wind Erosion Abrasion Sandblasting effect of wind Cuts & polish rock near surface

Wind Erosion Deflation Lifting and removal of loose material, Shallow depressions – blowouts Lower surface – desert pavement "The Big Hollow"

Suspension < 0.1 mm Parallel to surface & by strong winds. Return to earth when the wind subsides or down w/ precipitation. Can travel hundreds of miles.

Saltation .1 - .5 mm w/in 30 cm of surface short bounces along the surface and dislodging additional particles with each impact. 50 - 90% of the total movement of soil by wind. 

Surface Creep .5 – 1 mm Rolling & sliding of larger soil particles along the ground surface. Aided by the bouncing impacts of the saltation 5 - 25% of total soil movement by wind.

Wind Erosion While soil can be blown away at virtually any height, the majority (> 93%) of soil movement @ < 1 meter.

Wind Deposits Loess Blankets of silt (dirt)

Wind Deposits Dunes Mounds & ridges of sand

Types of Dunes Barchan dunes Due to wind in 1 direction No vegetation

Types of Dunes Transverse dunes  perpendicular to the prevailing wind

Types of Dunes Longitudinal dunes  parallel to prevailing wind

Types of Dunes Parabolic dunes  formed from “blowout” of vegetation

Wind Erosion 3 types of movement Suspension Saltation Surface Creep 4 types of dunes Barchan Transverse Linear Parabolic You should be able to discuss, define & or identify these types of movements & dunes