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Constructive or Destructive? Changing Earth’s Surface.

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Presentation on theme: "Constructive or Destructive? Changing Earth’s Surface."— Presentation transcript:

1 Constructive or Destructive? Changing Earth’s Surface

2 Constructive? Destructive?  What do these two terms mean? Constructive: Constructive: Destructive: Destructive:  What, on Earth, would you consider to be constructive and destructive?  What causes the constructive and destructive events on Earth?

3 Tectonic Plate Boundaries  As you know, tectonic plate boundaries are responsible for many changes on Earth. What are some of those features and events?  Which of these are Constructive? Destructive?

4 Volcanoes  Are Volcanoes constructive or destructive?  Give an example of when they could be one or the other, or even both.

5 Ring of Fire  The Ring of Fire refers to the large amount of volcanoes that wrap around the Pacific Ocean.  That sounds like a lot of new land being formed. How long do you think it takes to develop life on those islands?

6 What is a fault?  We are still dealing with compression, tension, and shear stress.  Faults and animations Faults and animations Faults and animations  More faults and animations More faults and animations More faults and animations  Hanging and Foot walls Hanging and Foot walls Hanging and Foot walls

7 The Three Types of Faults  Caused by tension  Caused by compression  Caused by shear stress

8 Mountains  How were mountains formed at tectonic plate boundaries?  How else do mountains form?

9 Mountains  By the end of this section you should have recorded information on Fault-block mountains Fault-block mountains Upwarped mountains Upwarped mountains Volcanic mountains Volcanic mountains Folded mountains Folded mountains

10 Aren’t All Mountains the Same?  Check out this little video about the types of mountains.  Mountains Mountains

11 The Four Types of Mountains  Fault BlockVolcanic

12 The Four Types of Mountains  Folded Upwarped

13 Can You Make It?  Mount Everest Game Mount Everest Game Mount Everest Game

14 What Do You Know?  In your assigned groups, answer the four questions with as many good answers as possible.  You are competing for bonus points, so don’t discuss your answers too loudly!!

15 Weathering  Weathering, in general, is the breakdown of rock into smaller and smaller pieces.  You may also consider the movement of material due to weathering processes

16 Mechanical Weathering  Mechanical weathering is the breakdown of rock by PHYSICAL means, such as ice, wind, water, gravity, plants, and animals

17 Mechanical Weathering - Ice  When water seeps into rocks and freezes, it expands.  When it expands, it breaks up the rocks.

18 Mechanical Weathering - Wind  Wind causes abrasion when it blows smaller rocks and sand against other rocks, which wears them down.  This action is like sandpaper.

19 Mechanical Weathering - Water  Moving water causes abrasion when it carries small rocks and particles with it, which rub against other rocks, wearing them down.  This action is like sand paper.

20 Mechanical Weathering - Water  Underground water flow can also cause sink holes.

21 Mechanical Weathering - Gravity  Gravity causes rocks and smaller particles to fall or tumble, causing abrasion when they rub against other rocks and wear them down.  This action is like sandpaper.

22 Mechanical Weathering – Plants and Animals  Plant roots move into existing cracks and then continue to grow, breaking up the rock.  Plant roots (which usually help hold soil) can cause the soil to loosen and erode in some areas.  Animals create burrows and tunnels through the soil, such as ants, worms, and moles.

23 Chemical Weathering  Chemical weathering is the breakdown of rocks and minerals into new substances by CHEMICAL means such as water, acids, air, and soil.

24 Chemical Weathering - Water  Water, even though it may be a slow process, can dissolve minerals and rocks.  This process is similar to you dissolving sugar in a glass of water.

25 Chemical Weathering – Acid Precipitation  Precipitation naturally contains small amounts of acid (such as sulfuric and nitric acids) which break down materials they come in contact with.  This is worse in areas with lots of factories.

26 Chemical Weathering – Acids in Ground Water  Sometimes water in the ground contains weak acids (such as carbonic or sulfuric acids) which dissolve rocks like limestone.  This process is what creates caves and caverns.

27 Chemical Weathering – Acids in Living Things  Organisms such as lichens, which grow on rocks (and trees), produce acids as a waste product.  These acids slowly break down the rocks.  This is how soil starts to form from rocks.

28 Chemical Weathering - Air  Oxygen in the air reacts with iron to create iron oxide – rust, which can be seen in rocks that contain iron.

29 Differential Weathering  When softer, less weather resistant rocks wear away and expose harder, more weather resistant rocks.  This is Devil’s Tower, which is the remains of the inside of a volcano.

30 Weathering Rate by Size  The smaller a rock is, the faster it will erode  Consider: dissolving a sugar cube or regular sugar

31 KEEP IN MIND...  The next slides of wave erosion, wind erosion, glaciers, and mass movement are all examples of mechanical weathering!!

32 Wave Energy  Waves carry a lot of energy, which is capable of moving large amounts of material.

33 Wave Energy - Beaches  Beaches are any area of shoreline made up of materials deposited by waves.

34 Wave Energy - Sea Cliffs  Waves erode and cut into the rock, creating steep slopes.

35 Wave Energy - Sea Arches  Sea Arches form when waves continue to erode the rock and cut through

36 Wave Energy - Sea Stacks  Sea stacks used to be connected to the mainland, but have been eroded.

37 Wind Erosion  Wind is powerful and can change the landscape.  The changes depend on the amount of wind and the material that makes up the land.

38 Wind Erosion - Dunes  Dunes are mounds of wind deposited sand that continue to move around.

39 Glaciers  A glacier, in general, is a large mass of moving ice.

40 Alpine Glaciers  Alpine glaciers form in mountainous areas.  These carve out rugged features in mountains.

41 Continental Glaciers  Continental Glaciers are large ice sheets that can cover millions of square kilometers.  Antarctica is covered by a glacier more than 1.5 X the size of the U.S. and that is even up to 4,000 meters thick in some places!

42 Glacial Deposits  Glacial deposits are all of the material that is carried and deposited by glaciers.

43 Glacial Deposits – Striated Drift  Striated Drift means that the rocks and material have been sorted out by size and are in layers.

44 Glacial Deposits – Till Deposits  Till deposits is unsorted material deposited by the glacier.

45 Mass Movement  Mass movement is the movement of any material down slope.  Gravity controls mass movement.  It can be a slow or fast process.

46 Mass Movement – Rock Fall  Loosened and exposed rock may fall in chunks or slide down a slope.  This happens quickly.

47 Mass Movement - Landslide  Large amounts of material move downward quickly.

48 Mass Movement - Mudflow  Mudflows are large amounts of flowing mud.  This happens when water combines with rocks and soil.

49 Mass Movement - Lahars  Lahars are mudflows made from water, soil, and volcanic ash.  This material is similar to concrete.

50 Mass Movement - Creep  Creep is a slow movement of areas of land.

51 References    _NRCS.jpg _NRCS.jpg _NRCS.jpg     growing_out_of_rock.jpg growing_out_of_rock.jpg growing_out_of_rock.jpg          st/1.jpg st/1.jpg st/1.jpg      

52 More references         bamfield-tofino-kayaking/barkley-sound-vancouver-island-deer-group-rock-sea-arch.jpg bamfield-tofino-kayaking/barkley-sound-vancouver-island-deer-group-rock-sea-arch.jpg bamfield-tofino-kayaking/barkley-sound-vancouver-island-deer-group-rock-sea-arch.jpg         

53 And Yet Even More References         GS_slide21.jpg GS_slide21.jpg GS_slide21.jpg  _cadd101.jpg _cadd101.jpg _cadd101.jpg      Lahar_Mount_Pinatubo.JPG Lahar_Mount_Pinatubo.JPG Lahar_Mount_Pinatubo.JPG      


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