Topic: Wind Erosion - T-Birds Earth...
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Topic: Wind Erosion
Transcript of Topic: Wind Erosion - T-Birds Earth...
Topic: Wind Erosion
A. Mainly in arid (dry) regions – little vegetation
B. Carries only small sediments
Wind erosion mainly occurs:
Which way was the wind blowing?
• Ventifact – rock abraded by wind-driven sand
• Approaching dust storm at Prowers County,
CO. Storm lasted from 4:15 PM to 7:00 PM.
"Fleeing a dust storm". Farmer Arthur Coble and sons walking in the face of a dust storm, Cimmaron County, Oklahoma. Arthur Rothstein, photographer, April, 1936. (Library of Congress)
Iraq, 2005
Dune Formation
http://highered.mcgraw-
hill.com/sites/0072402466/student_view0/chapter
13/animations_and_movies.html#
http://dli.taftcollege.edu/streams/Geography/Animations/CrossBedding.html
Types of Dunes
1. Barchan
2. Transverse
3. Linear
4. Parabolic
Parabolic Dunes, Napeague Bay
Parabolic Dunes, Napeague Bay
Parabolic Dunes, Napeague Bay
Eolian (Wind) Features
Topic: Wave Erosion
http://stevekluge.com/geoscience/images/waves2.jpg
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1604/es1
604page01.cfm?chapter_no=visualization
http://stevekluge.com/geoscience/images/waves2.jpg
Montauk Lighthouse on top of Turtle Hill, 297 feet from the tip of Montauk Point (1800)
Recent Photo 2001
Wave Erosion
Wave Erosion
Lake or Ocean waves removing sediments from the beaches.
North of Santa Cruz, California
Top View of the Beach
Ocean
Beach
Where is
my towel?
Long Shore Current
Sand
Long Shore Current
• Transports water & sediments parallel to the beach.
• Long Island’s (LI) Montauk to NY City (mainly east to west)
L.I. Natural Beach Features
1) Sand Bar
2) Spit
3) Lagoon (Great South Bay)
4) Barrier Island (Fire Island)
Diagram showing the environments of a barrier island system. (from Blatt, et al, 1980, Petrology of Sedimentary Rocks)
A sandbar off of Suffolk County, Long Island, New York, August 2006.
Fire Island, Barrier Beach
Davis Park
Democrat Point
L.I. Manmade Beach Structures
1) Jetty – keep inlets open
2) Groin – collect sand (large beach)
*BIG impact on the beach erosion rates.
Jetties
Jetty
Picture taken by Kory Gately
Groin
Beach
Long Shore Current Direction
Groin
What direction is the longshore current moving?
What direction is the longshore current moving?
Coastal Erosion
• http://www.youtube.com/watch?v=zUh3W
eilFN4
Final Question
What do you predict will happen to the
houses below?
Shape of Particles Vs. Form of Erosion
Shape of the Sediments
A. Water Erosion Produces rounded
particle Stream or beach
erosion (smooth and rounded)
B. Wind Erosion Produces rounded particles or particles
flattened on one side.
Appears rounded and frosted.
C. Glaciers Produces partly rounded and scratched
particles
A) Where bedrock is relatively soft, glacial grooves can be very deep. Glacial grooves in Devonian dolomite in Yule Creek a little east of the Yule Colorado Quarry. Gunnison County, Colorado. (All images and portions of captions from USGS).
U- shaped valleys
U Shaped Valley found in Greenland
D) Gravity and Physical Weathering
Produces angular particles
