1. What’s Wrong With This Picture? Take a minute to write down a list of what you think is wrong with these statues!

2. Changes in the Earth’s Surface Changes in the Earth’s Surface Chapter 1.3 Weathering & Erosion (Forces that change the Earth over a period of time….)

3. Weathering  Weathering: Breakdown of rock at or near the earth’s surface into smaller pieces. *2 Kinds of Weathering: *Mechanical Weathering *Chemical Weathering

4. Mechanical Weathering  Rock is broken/weakened physically  Frost Wedging: water freezes to ice in cracked rock, the ice expands and creates a bigger crack.  Seeds taking root in cracked rock.  Over time these types of weathering can cause huge parts of mountainside to break and fall away!!

5. Chemical Weathering  Mechanical weathering changes the structure of a rock, CHEMICAL weathering alters the rock’s chemical makeup  Can change one kind of rock into another  Water and Carbon Dioxide (air, soil)- when mixed =Carbonic acid

6. Chemical Change  The acidic water seeps into cracks (i.e.Limestone) and dissolves rock.  Acid Rain: Chemicals in the polluted air combine with water vapor and fall as acid rain.  Acid rain destroys forests, pollutes water, & eats away at the surfaces of buildings

7. Limestone Caves

8. Erosion  Movement of weathered materials such as gravel, soil, and sand.  3 Common Causes of Erosion: *Water *Water*Wind*Glaciers

9. Water  Largest canyons/deepest valleys created in part by moving water (rain, rivers, streams, oceans)  Water = Greatest cause of erosion.  Water carries sediment (small particles of soil/sand/gravel) which helps grind away surface rocks in the water’s path!  Sediment is eventually deposited (i.e. Mississippi River carries 159 million tons of sediment per year!)

10. Water Erosion-Devastating Effects FLOODING: Can occur when:  heavy, intense rainfall  run-off from a deep snow cover  over-saturated soil, when the ground can't hold anymore water. *Flooding causes erosion of the land and other physical characteristics. *Flooding also destroys private/public property and endangers lives.

11. New Orleans

12. Wave Action = Erosion

13. Historic New England Floods http://www.pbs.org/wgbh/amex/hurricane38/sfeature/ sf_footage.htmlhttp://www.pbs.org/wgbh/amex/hurricane38/sfeature/ sf_footage.html (Video Clip) http://www.pbs.org/wgbh/amex/hurricane38/sfeature/ sf_footage.html Houses were built on shifting sand, too close to the sea. Bridges were too flimsy, roads too low. When the September hurricane struck it brought massive flooding, one resident said, "It was your worst nightmare coming true.“  In the storm's aftermath, city streets became surreal junkyards full of debris, traveled by looters in rowboats. Entire beach communities disappeared. Thousands of livestock were killed. New England lost 275 million trees, including a third of Vermont's sugar maples. And hundreds of people died.

14. WIND  2 nd Major Cause of Erosion (esp. in areas with little water).  Loess  Sandstorms  Dust Bowl 1930’s (Video Clip) http://www.livinghistoryf arm.org/farminginthe3 0s/water_02.html http://www.livinghistoryf arm.org/farminginthe3 0s/water_02.html

15. Glaciers  Glaciers: Huge, slow-moving sheets of ice (form over years of unmelted snow pressed together, thaw slightly, and then turn to ice)  When glaciers move they carry dirt, rocks, and boulders. The glacier wears away the terrain in its path.

16. Glaciers: The Impact  Glaciers move (slide forward) due to their great weight  carve U-shaped  Basins of the Great Lakes  Moraines: ridge-like piles of rocks and debris left behind melted glaciers.  Long ridges of land (Long Island)

17. Icebergs