1. The dynamic earth

2. Do Now: What do you know about the planet Earth? Write down some things you know……

3. Scientists divide Earth into 4 parts or spheres: 1.Geosphere 2.Atmosphere 3.Hydrophere 4.Biosphere

4. THE DYNAMIC EARTH Scientists divide Earth into 4 spheres: 1.Geosphere- solid part of the Earth that consists of all rock, as well as the soil and loose rocks on Earth’s surface. In addition, all of the material beneath the Earth’s surface. Most of the geosphere is located in Earth’s interior 2.Atmosphere – mixture of gases that make up the air we breathe. Most of the gases are found in the first 30 km above Earth’s surface

5. 3. Hydrosphere – all of the water on or near Earth’s surface. Much of this water is found in the oceans. Also found in the atmosphere, and on land in soil. 4. Biosphere – area on Earth where life exists. Made of parts of geosphere, atmosphere, and hydrosphere.

6. Do the different spheres interact with each other? Or are they entirely separate entities? If they do interact, what are some examples of interacions?

7. Compositional layers Scientists divide earth into 3 layers, based on their composition. These layer are composed of progressively denser materials towards the center of the earth. These 3 compositional layers: Crust, mantle, core

8. Compositional layers of the Earth Crust o solid, brittle, outermost layer of Earth o Earth’s thinnest layer o makes up less than 1% Earth’s mass o 5 – 70 km thick o Continental crust (20 – 70 km thick) is thicker and made of light weight materials o Oceanic crust (5 – 8 km thick) is thinner and made of denser materials

9. Mantle o layer beneath the crust o 64% Earth’s mass o made of iron-rich and dense rocks

10. Core o sphere of hot, dense nickel and iron at center of Earth o composed of densest elements

12. Physical Layers of the Earth Lithosphere Asthenosphere Mesosphere Outer core Inner core

18. http://www.youtube.com/watch?v=Q9j1xG axYzYhttp://www.youtube.com/watch?v=Q9j1xG axYzY earth layer song

19. DO NOW What does the term “converge” mean? What does “diverge” mean? What do you think happens at convergent plate boundaries? What do you think happens at divergent plate boundaries?

20. The theory of plate tectonics

21. Theory of plate tectonics Lithosphere divided into pieces called tectonic plates. These plates glide across the underlying asthenosphere like ice drifts across a pond. Continents are located on tectonic plates and move around with them

22. Oceanic plates lie beneath ocean Continental plates lie beneath land masses Crust of oceanic plates is dense, rich in Fe Crust of continental plates contain more SiO 2 so less dense than Fe rich oceanic crust If the 2 plates collide, the continental plates are lighter and will rise above the oceanic plate

23. Oceanic and continental plates float on top of the denser material beneath them Their slow movements are driven by convection currents in the mantle (asthenosphere) As the plates move, the continents slowly drift As oceanic plates move apart, rising magma forms new oceanic crust on the seafloor at the boundaries between those plates (seafloor spreading)

24. Where oceanic plates meet continental plates, old oceanic crust is pulled downward, beneath the continental lithosphere and the heavier oceanic plate slides underneath the lighter continental plate. (aka subduction)

25. Consequences of Plate Movement Although the rate of plate movement is too slow for us to notice, geologic activity provides lots of evidence that plates are in motion Example: Hot spots – areas where plumes of hot magma well up from the mantle and reach the lithosphere

26. As a plate moves over a hot spot, heat from the rising mantle plume melts the crust, forming a volcano (Volcano – vent in Earth’s surface that emits ash, gas, and molten lava) Over time, as the plate moves past the hot spot, it can leave behind a trail of extinct volcanic islands, each with the same chemical composition Example – Hawaiian islands

27. http://www.youtube.com/watch?v=uGcDed 4xVD4http://www.youtube.com/watch?v=uGcDed 4xVD4 http://www.youtube.com/watch?v=uGcDed 4xVD4http://www.youtube.com/watch?v=uGcDed 4xVD4 Earth in 100 million years

28. http://www.bing.com/images/search?q=Ha waiian+Hotspot+Animated&view=detail&id =87DD9350C5EC1325D4E62950DBDDC 09BB9CB5D01http://www.bing.com/images/search?q=Ha waiian+Hotspot+Animated&view=detail&id =87DD9350C5EC1325D4E62950DBDDC 09BB9CB5D01

30. Major Tectonic Plates Pacific North American South American African Eurasian Antarctic (page 66 in text nice pic)

33. http://www.classzone.com/books/earth_scie nce/terc/content/visualizations/es0804/es0 804page01.cfm?chapter_no=visualization animation for plate boundaries http://www.iris.edu/hq/programs/education_a nd_outreach/animations/11 more animation

34. Plate Boundaries Most geologic activity at the surface of the Earth takes place at the boundaries between tectonic plates. Plates can move away from each other, collide with one another, or slip past one another Huge amounts of force generated at these boundaries when the plates move, causing mountains to form, earthquakes to shake the crust, and volcanoes to erupt

35. Plate Boundaries The area where 2 plates meet is called a plate boundary. 3 main types of plate boundaries: 1.Divergent 2.Convergent 3.Transform

36. Plate Boundaries The three main types: 1- Divergent- plates move apart (usually under oceans) 2- Convergent- plates come together 3- Transform- plates slide horizontally pass each other

38. Identifying Plate Boundaries - Scientist plot the occurrences of earthquakes around the world -Since movement is most common near plate boundaries, this is where most of the earthquakes and volcanic eruptions occur

42. Transform Boundaries 2 plates slide past each other This sliding is not smooth. Plates lock and build up tension. After too much tension builds, the plates “snap” and move against each. Cause earthquakes Example – San Andreas Fault, CA (Pacific plate and North American plate are sliding past one another

45. Divergent Boundaries Two plates separate or move away from each other Oceanic plates move apart; magma from mantle reaches Earth’s surface and pushes outward and upward; new rock is formed That’s called – sea floor spreading. It creates new lithosphere and brings important elements such as Cu, Pb, and Ag to Earth’s surface Cause earthquakes and volcanic activity Create rift valleys and mid ocean ridges – for example: creates Mid-Atlantic Ridge which is visible on land in Iceland Most common on ocean floor

47. Mid-Ocean Ridge System

48. Formation of New Ocean Floor

50. These red triangles represent Iceland’s volcanoes. Why are there so many?

51. Volcanic eruptions are common in Iceland

52. Convergent Boundaries Plates move towards each other and collide 3 types of convergent boundaries 1. Continental plate collides with oceanic plate (subduction)- makes deep ocean trenches, land volcanoes, and earthquake activity Ex: Andes Mountains 2. Oceanic plate collides with oceanic plate- causes earthquakes, deep ocean trenches and island arcs (chain of volcanic mountains) Ex: Mariana islands and Mariana trench

53. 3. Continental plate collides with continental plate (collision)- the crust becomes thicker, is pushed up, and eventually forms a mountain range Makes large land mountain ranges, also causes earthquakes, and volcanic activity Ex: Himalayan Mountains

55. Subduction Zone Continental + Oceanic Crust

56. Subduction Zone Oceanic + Oceanic Crust

57. Subduction Zone Oceanic + Oceanic Crust (another view)

58. Collision of Continental + Continental Crust

60. Hot Spots (mantle plume)- Not a Boundary These are stationary pockets of magma inside of a plate’s boundaries (not at the edges). Hot Spots can create new land by building volcanoes that peak out of the ocean Can create volcanic mountain chain as plates move over, with active volcanism over the plume Ex: Hawaiian Islands

61. Which mountain Is oldest?

64. Think….. If divergent plates allow magma to surface creating new ocean floor, then why isn’t Earth getting larger?

66. Earthquakes!

67. Pakistan Earthquake Occurred Saturday October 8, 2005 Magnitude of 7.6 Occurred in foothills of Himalayans

68. Homes left in ruin

69. 69,000 Injured

70. A man sits in what is left of his home

71. This was a 10 story apartment

72. A local school- 100 children died here

73. A Classroom- 5 children died here

74. Estimated 86,000 died

75. Magnitude 8.7!

85. For you to do : Research 1 major earthquake, tsunami, landslide or volcanic eruption Describe where and when it took place State what type of boundary it was near Was there any warning? Effects – damage, injury, lives lost, etc How was the recovery/relief effort? Make a brief power point to share with the class; put in lots of pictures to make it interesting!