1. Constructive and Destructive Forces

2. Constructive Forces Identify surface features caused by destructive forces.
Construct means to build up.
Forces that build up features on the surface of the Earth.
Sediment (Deltas, sand dunes, etc.)
Volcanoes (makes Islands)
Tectonic Plates (Mountains)
Crust deformation (Folding or Faulting)

3. Sediment The process of sediment being carried causes new landforms.
Wind – sand transported by the wind creates sand dunes.
Water – bits of soil and rock can be carried downstream and deposited causing deltas.
Ice – glaciers pick up and move rock and other materials, depositing it elsewhere.

4. Wind Deposition Sand Dune Cumberland Island, GA

5. Water Deposition Sediment is carried by river

6. Glacial Deposition

7. Volcano Volcanos can be both constructive and destructive

8. Volcanoes
A volcano is an opening in the Earth's surface or crust, which allows hot, molten rock, ash and gases to escape from deep below the surface.
Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.
Magma (inside)
Lava (outside)

9. Volcanoes There are two main types of volcanoes: shield and composite.
Shield volcanoes are usually found in the middle of tectonic plates. Islands like Hawaii are good examples of this type of volcano. These are making new islands every year…takes a long time. (Hawaiian Islands)
There's a hole in the middle of the plate and magma moves out and piles on top of itself, slowly building a mountain of rock. (Katmai)

10. Volcanoes
1. Magma reservoir 2. Country rock 3. Conduit (pipe) 4. Base 5. Sill 6. Branch pipe 7. Layers of ash emitted by the volcano 8. Flank 9. Layers of lava emitted by the volcano 10. Throat 11. Parasitic cone 12. Lava flow 13. Vent 14. Crater 15. Ash cloud

11. HOT SPOT
content/visualizations/es0904/es0904page01.cfm?chap ter_no=visualization

12. Tectonic Plates
Mountains can be formed because of moving tectonic plates.

13. Faults Faults are cracks in the Earth’s crust.
The surface of the Earth is made up of tectonic plates that are floating on magma (molten rock).
It is along these fault lines that earthquakes and volcanoes occur.

14. Erosion and Depositionw M

15. Destructive Forces Identify examples of surface features caused by destructive processes.
Destruct means to destroy.
Forces that destroy features on the Earth’s surface.
Erosion (water - rivers and oceans, wind)
Weathering (chemical or mechanical)
Impact of organisms
Earthquake

16. Earthquakes
An earthquake is a phenomenon that results from the sudden release of stored energy in the Earth’s crust.
It is caused by a strain on the fault lines of the Earth’s crust. When the energy of the strain is released, similar to a rubber band snapping, the earthquake occurs.
At the Earth's surface, earthquakes cause a shaking or displacement of the ground and sometimes cause the ground to break apart and change shape. Earthquake Animation!

17. Earthquake

18. Earthquakes
More than buildings collapse when an earthquake hits. The land itself is totally changed. You can see scars across the landscape. Those scars appear when one block of land has moved compared to another. Roads often change their placement. They either become uneven or just crack. Streams can also change course. Sometimes rocks can fall and block the stream. Other times, the land is even lowered in certain areas. When it's lower, it's easier for the water to flow in the new direction .

19. Weathering and Erosion
Weathering is the breakdown of the continents and the land around you. The breaking down of these rocks and land due to forces such as wind and water is weathering. When it rains, rocks are washed down a mountain or down a stream. Soils are washed away. The ocean beats against a cliff and breaks it apart. If it is moved elsewhere it is called erosion.

20. Mechanical Weathering
Mechanical weathering is the process of breaking big rocks into little ones. This process usually happens near the surface of the planet. Temperature also affects the land. The cool nights and hot days always cause things to expand and contract. That movement can cause rocks to crack and break apart. Roots and plants also push into the rocks and break them apart. They act like wedges and push the rocks apart. Little animals also help by burrowing and digging through the ground.

21. Chemical Weathering
Chemical weathering includes the effect of weathering on molecules and atoms. As with all chemistry, the greater the surface area of an object, the more chemical reactions can take place. For these chemical reactions to happen in nature, moisture, and heat must be present.

22. Biological Weathering (Impact of Organisms)
Biological weathering would include the effect of animals and plants on the landscape. This is more than roots digging in and wedging rocks. Biological weathering is the actual molecular breakdown of minerals.

23. Technology and Human Interventions
Humans try to CONTROL these forces.
seismological studies
flood control (dams, levees, storm drain management, etc.)
beach reclamation (Georgia coastal islands)

24. Stone Mountain formed by plate tectonics

25. Emerson fault

26. Gorge

27. Providence Canyon, GA

28. Appalachian Mountains

29. Sand Mountain

30. Lime sinks-chemical dissolution of rocks

31. Pine Mountain Chain Rock and KY first state park

32. Cumberland Falls Only Falls with Moonbow

33. Beaches

34. Brasstown Bald highest natural point in GA

35. Brevard Fault Zone

36. Cumberland Plateau

37. Lookout Mountain last battle of Cherokees

38. Blue Ridge Mountains

39. Mississippi River largest drain in USA

40. Study Jams Landforms
Physical Geography – Forces that shaped our Earth
GeoAmerica: Mississippi Delta Blues
Study Jams – Weathering and Erosion