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Our Amazing Planet

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Our Amazing Planet Evidence of Pangaea Similar Mountain Ranges Similar Rocks Rock Striations Match Convection Currents in the Mantle Causes Sea Floor Spreading The ... – PowerPoint PPT presentation

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Title: Our Amazing Planet


1
Our Amazing Planet
2
Planet Earth
  • Earths Layers

3
Crust
  • Earths thin outermost layer.
  • Continental Crust (land) - thick low density rock
    (granite).
  • Oceanic Crust (sea floor)- thin dense rock
    (basalt)?

4
Mantle
  • Earths thickest layer made of dense iron-rich
    super heated soft rock.
  • Where convection currents occur.

5
Core
  • Earths innermost layer made of hot, dense iron
    and nickel.
  • Outer core - Liquid
  • Inner core - Solid

6
Lithosphere
  • Earths outermost layer
  • Includes the crust and solid upper part of the
    mantle.
  • Divided into huge pieces called Tectonic
    Plates.
  • Move around on top of the asthenosphere - very
    hot, soft layer of the mantel.

7
Earths Tectonic Plates
8
Continental Drift
  • Theory that the Earths continents move over time
  • Proposed by Alfred Wegener in the early 1900s
  • Evidence of Continental Drift
  • Continents fit together
  • Similar fossils records
  • Similar rocks and minerals
  • Similar rock formations and striations
  • Similar climatic conditions Glaciations

9
Evidence of Pangaea
10
Continents Fit Together
11
South America and Africa
12
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13
Similar Fossil Records
14
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15
Similar Mountain Ranges
16
Similar Rocks Rock Striations Match
17
Other Evidence - Glaciations
18
Sea Floor Spreading
  • Occurs where tectonic plates spread apart at Mid
    Ocean Ridges
  • Magma rises from inside the Earth creating new
    sea floor.
  • New sea floor pushes the existing sea floor out
    explaining why continents move.
  • Evidence that supports the theory of Continental
    Drift.

19
Sea Floor Spreading New crust is formed at
mid-ocean ridges spreading the sea floor
20
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21
Mid-Atlantic Ridge
22
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23
Convection Currents in the Mantle
  • Causes Sea Floor Spreading
  • The main cause of plate tectonics
  • Convection Currents
  • Hot magma rises and cooler magma sinks in the
    Earths Mantel

24
Tectonic Plate Boundaries
25
Convergent Boundaries
  • Tectonic plates collide -
  • Forms trenches, mountains, and subduction zones
  • CTMS Convergent trenches mountains -
    subduction

26
Convergent Boundaries Subduction Zones
  • Creates trenches in the ocean and mountains and
    volcanoes on land

27
Divergent Boundaries
  • Tectonic plates move apart
  • Forms Mid Ocean Ridges in oceans and Rift
    Valleys on land
  • East African Rift
  • Mid-Atlantic Ridge

28
Mid-Ocean Ridges
  • Chain of volcanoes at the middle of the ocean
    floor.
  • Causes Sea Floor Spreading
  • Magma comes up from inside the Earth, cools and
    hardens and creates new sea floor.
  • The rock at the mid-ocean ridge is the youngest
    and gets older as it moves farther away from the
    ridges.

29
Mid-Atlantic Ridge
30
Transform Boundaries
  • Tectonic plates slide past each
  • Forms Fault lines
  • San Andreas Fault in California

31
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32
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33
Volcanoes and Earthquakes Most Occur at Tectonic
Plate Boundaries
34
Ring Of Fire
35
Ring of Fire
  • Volcanoes around the Pacific Ocean caused by
    tectonic plates colliding into each other
    creating subduction zones at CONVERGENT
    boundaries.

36
Hot Spots
  • Areas in the middle of tectonic plates where
    magma inside the Earth rises through the crust
    and forms volcanoes.
  • Like the Hawaiian Islands

37
Hawaii Islands
38
Super Volcano
  • Yellowstone National park
  • Underground volcano caused by another Hot Spot
  • 3 overlapping calderas underground is believed to
    have formed from a hot spot creating
    Yellowstones Super Volcano

39
Yellowstone
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