wind erosion & deposition
DESCRIPTION
Wind erosion & Deposition. WED V15. What is wind?. Wind the horizontal flow of air. It is caused by horizontal differences in pressure which result from the unequal heating of Earth’s surface - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/1.jpg)
WED V15
WIND EROSION & DEPOSITION
![Page 2: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/2.jpg)
WHAT IS WIND?
Wind the horizontal flow of air. It is caused by horizontal
differences in pressure which result from the unequal heating of Earth’s surface
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1903/es1903page01.cfm?chapter_no=visualization
![Page 3: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/3.jpg)
FEATURES CAUSED BY WIND
Ripples and dunes
![Page 4: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/4.jpg)
Windward side is gentle
Leeward side is steep
http://geology.wr.usgs.gov/parks/coast/dunes/index.html
![Page 5: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/5.jpg)
FOR DUNES & RIPPLES TO FORM YOU NEED…
Wind Dry sand Wind break (drift wood, dead
bird, plant, etc.)
![Page 6: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/6.jpg)
DUNES
http://geology.wr.usgs.gov/parks/coast/dunes/index.html
![Page 7: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/7.jpg)
DUNE FORMATION steady supply of sand, wind, and a wind break
beaches and at the base of mountains in dry regions.
Wet sand will not blow around to form ripples and dunes
Mesquite Flats, Death Valley, CAhttp://www.uoregon.edu/~millerm/sanddunes.html
![Page 8: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/8.jpg)
GRASSES ON THE DUNES HELP STABILIZE THE BEACH
http://geology.wr.usgs.gov/parks/coast/dunes/index.html
![Page 9: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/9.jpg)
http://www.nps.gov/archive/grsa/resources/images/photos/dune_pattern03.jpg
Wind blows sand and makes ripples Once sand begins to pile up, ripples and dunes can form.
![Page 10: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/10.jpg)
RIPPLES GROW INTO DUNES WITH INCREASE OF WIND
AND SAND INPUT
http://geology.wr.usgs.gov/parks/coast/dunes/index.html
![Page 11: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/11.jpg)
The collapsing sand comes to rest when it reaches just the right steepness- 30 to 34 degrees, or angle of repose- to keep the dune stable.
http://geology.wr.usgs.gov/parks/coast/dunes/index.html
![Page 12: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/12.jpg)
SAND BLOWING OFF A DUNE
http://www.uoregon.edu/~millerm/depenv.html
![Page 13: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/13.jpg)
ANIMATION
http://highered.mcgraw-hill.com/sites/0072402466/student_view0/chapter13/animations_and_movies.html#
![Page 14: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/14.jpg)
MIGRATION sand inches up the windward side to the
dune crest
then slips down the dune's slip face
the dune to inches forward, migrating in the direction the wind blows
this leaves its mark on the internal structure of the dune.
http://geology.wr.usgs.gov/parks/coast/dunes/index.html
![Page 15: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/15.jpg)
CROSS-BEDDING PRESERVED IN SANDSTONE
http://www.wwnorton.com/college/geo/egeo/flash/5_1.swf
http://geology.wr.usgs.gov/parks/coast/dunes/index.html
![Page 16: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/16.jpg)
NAVAJO SANDSTONE
![Page 17: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/17.jpg)
CROSS BEDDING IN THE NAVAJO SANDSTONE
ARCHES NATIONAL PARK
![Page 18: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/18.jpg)
STAR DUNE COMPLEX
The wind blows from different directions throughout the year.
http://www.nps.gov/archive/grsa/resources/images/photos/dunes_cristos03.jpg
![Page 19: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/19.jpg)
MAIN DUNE FIELD AT WHITE SANDS NATIONAL MONUMENT
http://www.nps.gov/archive/grsa/resources/images/photos/landscape_sw02jpg.jpg
![Page 20: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/20.jpg)
http://www.nps.gov/archive/grsa/resources/photos_landscape.htm
![Page 21: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/21.jpg)
http://www.nps.gov/archive/grsa/resources/photos_landscape.htm
![Page 22: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/22.jpg)
http://www.nps.gov/archive/grsa/resources/photos_landscape.htm
![Page 24: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/24.jpg)
VENTIFACTS
http://earthsci.org/education/teacher/basicgeol/windes/ventifact.gif
![Page 25: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/25.jpg)
FEATURES CAUSED BY WIND
Ventifacts rocks flattened and smoothed
by wind abrasion
![Page 26: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/26.jpg)
![Page 27: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/27.jpg)
FEATURES CAUSED BY WIND
Desert pavement
Surface where wind has blown away the smaller sediment
Deflation: removal of silt, sand, and clay by wind
![Page 28: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/28.jpg)
DESERT PAVEMENT
http://media-2.web.britannica.com/eb-media/28/10728-004-83F5D724.jpg
![Page 29: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/29.jpg)
http://www.uwgb.edu/DutchS/geophoto/aeolian/DPAVMT1.jpg
![Page 30: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/30.jpg)
http://www.goldengatephoto.com/jpeg/99-29-7.jpg
![Page 31: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/31.jpg)
EVIDENCE OF WIND ABRASION: FROSTED GRAINS
http://en.wikipedia.org/wiki/File:WhiteSandsGypsum.jpg
![Page 32: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/32.jpg)
LOESS Wind-blown silt
deposits
Often forms thick layers as wind deposits small particles swept from glacial outwash plains
http://en.wikipedia.org/wiki/File:LoessVicksburg.jpg
![Page 33: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/33.jpg)
“When the Yellow River runs clear”
Means the same as
“When Pigs fly”
http://upload.wikimedia.org/wikipedia/commons/e/ea/Hukou_Waterfall.jpg
![Page 34: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/34.jpg)
http://en.wikipedia.org/wiki/File:Loess_landscape_china.jpg
![Page 35: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/35.jpg)
The photograph below shows a sand dune that formed in a coastal area.
This sand dune was most likely formed by(1) water flowing from the left(2) water flowing from the right(3) wind blowing from the left(4) wind blowing from the right
![Page 36: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/36.jpg)
![Page 37: Wind erosion & Deposition](https://reader033.vdocuments.us/reader033/viewer/2022051020/56816304550346895dd37ec1/html5/thumbnails/37.jpg)
DRAW THE SAND