1. 5 minute check November 6, 2013 What is the difference between a constructive and a destructive force ? 4.34.3 - The student will describe how landforms are the result of a combination of constructive and destructive processes.

2.  Destructive Forces: processes that destroy landforms. ◦ 2 types: Slow (weathering) and Fast (Erosion) ◦ Ex. landslides, volcanic eruptions, earthquakes, floods  Constructive forces: forces that build up an existing landform or create a new one. ◦ Caused by: water, gravity, wind and glaciers. ◦ Ex: deposition, landslides, volcanic eruptions, floods

3.  Destructive forces – destroy and wear away landmasses through processes like weathering and erosion. ◦ Weathering – wearing by wind, precipitation, freezing/thawing ◦ Erosion – wearing down & carrying away of land by natural forces  Destructive forces are those that are recycling the Earth, like Earthquakes and plate movement.  One example is when wind erodes or takes away some of the sand on a sand dune or beach.  Farming is a destructive process, because the soil has to be dug up and moved around in order to grow plants. Mining is another destructive process, because we dig holes into the earth or blow up parts of the earth and/or caves in order to get what we want.

4.  Weathering: a slow, destructive force that breaks rocks into smaller pieces called sediments. Can be by a physical (mechanical) or chemical process. Weathering Pictures

5. Mechanical weathering: the breaking of rock into smaller pieces by forces due to gravity, ice, plant roots, or other physical forces.

6. Chemical Weathering: the changing of materials in a rock by chemical processes.

7.  Erosion: the destructive movement of materials away from one place by wind, water, ice and gravity. Wave Erosion- caused by water Wind Erosion (Dust Storm) Grand Canyon Video

8.  Landslides: occur when gravity quickly pulls rock and dirt downhill.

9.  Floods: a great flow of water over an area that is usually dry land.

10.  Volcano: an opening in the Earth’s crust through which steam, lava and ashes erupt.  Cause both destructive and constructive changes to landforms.

11. Saint Helen’s Before Saint Helen’s After Mount St. Helens Video

12. Volcanoes can be constructive, but also destructive…

13.  Earthquakes: the shaking of Earth’s surface caused by the release of energy along a fault. San Andreas Fault, California

14.  Constructive forces – shape earth’s surface by building up mountains, volcanoes and other landmasses caused by plate movements. It makes positive changes!  One example of a constructive process is when sand is deposited onto a river bank by the running water. This builds up the river bank, making it higher.  Another example of a constructive process is a volcano erupting. This builds up the land around the volcano, making it higher.

15.  Any type of geological event where land is uplifted.  Uplift - the movement of fault block (normal fault)  Mountain Building- the convergence of two plates

17.  Deposition: the placing of materials in a new place (constructive force).  Ex. Sandbars

18.  River Delta - Deposits of sediment at the mouth of the Mississippi River creating new land called a delta.

19.  Sand Dunes- sand is moved by wind Desert Sand Dunes Ocean Sand Dunes

20. The Bernard Glacier in Alaska's Saint Elias Mountains Grand Canyon – sandstone rock New York – lichen on granite; secrete chemicals that break down rock

21. 5 minute check November 7, 2013 Give an example of a Constructive and a Destructive force? 4.34.3 - The student will describe how landforms are the result of a combination of constructive and destructive processes.

22.  Destructive Forces: processes that destroy landforms. ◦ 2 types: Slow (weathering) and Fast (Erosion) ◦ Ex. landslides, volcanic eruptions, earthquakes, floods  Constructive forces: forces that build up an existing landform or create a new one. ◦ Caused by: water, gravity, wind and glaciers. ◦ Ex: deposition, landslides, volcanic eruptions, floods

23.  Any type of geological process that destroys or moves land  Weathering- the process of breaking down rock into smaller pieces ◦ Chemical- acid rain breaks down rocks Example: Granite gravestones and statues ◦ Mechanical- the use of mechanical force to break apart rocks Example: plant growing in sidewalk

24.  Any type of geological process that destroys or moves land  Erosion- the process of moving sediment ◦ Glacial Erosion- glaciers push rocks and move them downhill Example: Alaska glaciers and alpine glaciers ◦ Wind Erosion- wind picks up and carries sediment Example: moving sand dunes ◦ Gravity Erosion- gravity forces rocks and large landmasses downhill Example: landslides

26.  Constructive forces: forces that build up an existing landform or create a new one. ◦ Caused by: water, gravity, wind and glaciers. ◦ Ex: deposition, landslides, volcanic eruptions, floods

28. pine tree eroded by wind Nevada’s Great Basin National Park A- Constructive B-Destructive

29. pine tree eroded by wind Nevada’s Great Basin National Park A- Constructive B-Destructive

30. Lake Tahoe – created by a normal fault A- Constructive B-Destructive

31. Lake Tahoe – created by a normal fault A- Constructive B-Destructive

32. Sierra Nevada Mountains A- Constructive B-Destructive

33. Sierra Nevada Mountains A- Constructive B-Destructive

34. Spring Mountain Range (Mt. Charleston) A- Constructive B-Destructive

35. Spring Mountain Range (Mt. Charleston) A- Constructive B-Destructive

36. Red Rock Canyon A- Constructive B-Destructive

37. Red Rock Canyon A- Constructive B-Destructive

38. Valley of Fire A- Constructive B-Destructive

39. Valley of Fire A- Constructive B-Destructive

40. Grand Canyon A- Constructive B-Destructive

41. Grand Canyon A- Constructive B-Destructive

42. 5 minute check November 8, 2013 What are all the names for the hot stuff that comes out of volcanos? 4.34.3 - The student will describe how landforms are the result of a combination of constructive and destructive processes.