down and build up the land? Sand Blasted Text pages A20-A21 How does wind wear down and build up the land?

Wind is a powerful force Wind is not as powerful as moving water. But wind can change the shape of the land. The stronger the wind, the more sediments it can carry. Wind must blow at least 18km/hour or 11 mph in order to move sand along the ground. Wind erodes Earth’s surface by removing sand and silt from one place and depositing them in another, The sediments that the wind carries also weather Earth’s surface. The following slides illustrate the type of change that wind can cause on Earth’s surface.

Sand dunes Let’s click on the website below to view the creation and erosion of a sand dune. http://www.nwlg.org/pages/resources/geog/hydro_cycle/dunes/stop7b.htm

Sand dunes and their formations Let’s click on the websites below to see how a sand dune forms over time. http://oceanica.cofc.edu/An Educator'sl Guide to Folly Beach/guide/process5.htm http://www.nps.gov/grsa/resources/geology.htm Active dune field

2 1 4 3 5 Formation of a sand dune Let’s number the steps in the correct order that describe the formation of a Sand dune 2 _____ The wind slows down when it strikes an object _____Wind removes loose sand and silt from an area _____Over time a sand dune forms _____Wind deposits sediment in another area _____ The process begins all over again 1 4 3 5

Erosion by windblown sand can help shape the surfaces of rock formations such as this butte. A butte Is a narrow-topped hill with very steep cliff like sides.

How do glaciers change the land over which they move? Nature's Bulldozers Text pages A22-A24 How do glaciers change the land over which they move?

Click once to view an animation of the retreat of a glacier. Glacier Formations Glaciers are natures natural bulldozers. Glaciers are a huge mass of slow moving ice that forms over land. Click once to view an animation of the retreat of a glacier. V-shaped valley cut by a glacier

Glaciers There are two types of glaciers. Valley Glacier or Alpine Glacier Continental Glacier or Ice Sheets

Valley glaciers Also called alpine glaciers, these thick “rivers” of ice form in high mountain ranges Valley glacier V-Shaped valleys are created by a river’s erosion. Click the link below to view an animation of how a glacier carves a v-shaped valley into a U shaped valley. http://rds.yahoo.com/_ylt=Aja_0okIYMyVZ6cqeqb8NRlXNyoA;_ylu=X3oDMTE2NW1udWJ2BGNvbG8DZQRsA1dTMQRwb3MDMQRzZWMDc3IEdnRpZANGNjY1Xzc0/SIG=11i0at8gl/EXP=1134678183/**http%3a//www.nps.gov/olym/uv.htm

Continental glaciers- Also called ice sheets, these gigantic Masses of ice are found only in Greenland and Antarctica Continental glacier

The size of this glacier can be measured when you compare the glacier with the helicopter.

What ice (glaciers) leave behind Rivers and Lakes The Matterhorn was carved by glaciers. It has 4 triangular faces that Are each about the same size. What space Shape is this peak most like?

Carved Valleys and Mountain Ranges What ice (glaciers) leave behind Carved Valleys and Mountain Ranges The landscape of Vermont, as well as the landscape of much of northern North America, Europe and Russia has been profoundly affected by glaciation over the last 1,500,000 years. Erratics Erratics are large boulders dropped by a glacier as it melts or retreats.

Moraine What ice (glaciers) leave behind Moraine is rock material that a glacier will carry with it. As the glacier retreats, the moraine is left behind. The moraine that is left behind at the glacier’s farthest point is called the terminal moraine. This is the glacier’s largest deposit.

What ice (glaciers) leave behind In which direction do you think this glacier traveled? Glacier Grooves Glacier grooves are created by the moraine on the bottom of a glacier carving and cutting out the surface under the glacier leaving grooves in the rock. The grooves show the size of the glacier and the direction the glacier traveled.

Review Questions from text page A24 1.) Name and describe two types of glaciers. 2.) What are some signs that show that a giant ice sheet once covered an area? 3.) How do sediments that are deposited by wind compare with those deposited by glaciers? 4.) Glaciers move very slowly, yet they can transport huge amounts of sediments. Explain how this is possible.