Warm-Up October 28 The Grand Canyon is an example of a young, middle-aged, or old river?

1. Warm-Up October 28 The Grand Canyon is an example of a young, middle-aged, or old river? How do you know? Old, the river bed is U-shaped.

2. Earth Science Rocks! • MYP Unit Question:How does land change? • Area of Interaction:Environment • Learner Profile:Caring and Principled • Standard:Investigate the scientific view of how the Earth’s surface is formed.

3. Bell Ringer: Fastest Wind on Earth • Learning Target: Today I’m learning about erosion by wind because I want to understand how to prevent it. • Work Session: Notes – Erosion by Wind • Closing: Erosion Song

4. On April 12, 1934 at the Mount Washington Observatory in New Hampshire the staff were busy recording wind speeds as an intense storm moved in. Early in the morning wind speeds exceeding 100 MPH were recorded and they continued to increase, it wasn't long till the wind hit speeds of 150 MPH. As the day wore on the winds topped 200 MPH with frequent gusts reaching 220 MPH. Fastest Wind in the World

5. Then it happened . . . at 1:21pm on April 12, 1934 a wind gust was recorded at 231 MPH or 372 KM/H, the fastest surface wind speed ever recorded on Earth. Everything is covered with rime, a kind of ice that forms when water droplets freeze on a cold surface.

6. Erosion by Wind • Wind carries and deposits sediment. • The amount and the size of particles the wind can carry depend on the wind speed. • Deserts, coastlines, and areas with little plant coverage are the most affected by wind erosion. • p. 350-351

7. In areas where strong winds occur, sand grains knock into one another, some grains bounce up in the air, fall forward, and hit other sand grains. (Abrasion)

8. Sand dunes • form from material deposited by wind.

9. Example: Sand dunes at the beach

10. Example: Sand Dunes in the desert

11. Example: Sand Dunes leeward windward

12. Example: Barchan dune east of Gilf Kebir Plateau Saudi Arabia Crescent shaped dunes formed from a unidirectional (one-direction) wind. Barchan dunes of the Namib Desert

13. Example: Hueco Bolson Desert – Texas Ripple marks are miniature dunes within a dune (not more than 2 inches tall). Formed by cross winds and appear to be traveling in a different direction than the large dune.

14. Example: Rock formations in the Wadi Desert in Egypt

15. Example: Arches National Canyon, Utah Formed when wind and water weather (erode) softer material first.

16. Example: Ventifact on Mt. Falconer - Canada Wind carries fine particles that work like a sand blaster (i.e. sand, silt, clay, and ice particles)

17. Example: Desert pavement Formed in arid environments when wind carries finer, more lightweight particles such as sand away. Large particles are left behind and protect from further erosion.

18. Example: Loess Deposits - Banks, Pennsylvania Yellowish, fine grained silt and clay sized particles formed by glaciers millions of years ago; carried and deposited by wind.

19. Example: Pedestal rockAfrica Base of a rock is weathered and eroded more quickly due to sand blasting. Sand grains can only be picked up a couple of feet.

20. Erosion by human activity Human activity causes 10 times more erosion of the continental surface of the Earth than all natural processes combined.

21. Why does this matter? Earth's surface involves a balanced process, where new soil forms at about the same rate as it erodes. • If humans are stripping soil at that rate, nature won't be able to keep up.

22. Why is this critical?Two Reasons • The Earth's human population is growing rapidly. • Almost all the land that is capable of producing crops is being used. What can we do?

23. Soil Conservation--Terracing Banaue rice terraces in the Philippines

24. Soil Conservation—Crop Rotation • Crop Rotation George Washington Carver

25. The Dust Bowl of the 1930s

26. Check each page Cover—definition of Erosion Booklet pages • notes • quality drawings • Labels Standards Check Exit Ticket

27. Closing: Erosion Song