1. All solid parts of Earth
What is the GEOSPHERE?
All solid parts of Earth
Rocks, soils, minerals, sediments, magma
The Grand Canyon, AZ

2. What are the layers of the Earth?
=WwiiOjyfvAU

3. Chemical Layers of the Earth
Geologists classify Earth’s layers two ways: chemically and physically
Chemical – by composition
Physical- by structure
Chemical Layers of the Earth
Crust- O, Si, Al
Mantle- O, Si, Mg, Fe
Core- Fe, Ni

4. Physical Layers of the Earth
Lithosphere
Crust and upper mantle combined
Broken in chunks called tectonic plates
Oceanic plates are thinner and denser than continental plates
Asthenosphere
Layer of Jello-like magma in the mantle
Tectonic plates move due to convection currents in the asthenosphere

5. Physical Layers, cont. Mesosphere The rest of the mantle; molten rock
Outer Core
Liquid metal
Surrounds inner core
Inner Core
Densest layer
Solid metal

7. Theory of Plate Tectonics
Lithosphere (upper mantle and crust) is 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

9. Seafloor Spreading Magma rises from asthenosphere
Creates new oceanic lithosphere
Pushes tectonic plates apart

11. Seafloor-Spreading

14. If new crust is being created by the process of seafloor spreading, is the Earth growing!?

15. Subduction
Subduction zones: A region where old crust is destroyed as it is pulled back down into the mantle

16. Plate Boundaries
The area where two plates meet is called a plate boundary.
Most earthquakes and volcanoes occur at or near plate boundaries
Three main types of plate boundaries:
Divergent- separating
Convergent- colliding
Transform- scraping past

19. Transform Boundaries 2 plates slide past each other
Not smooth. Plates lock, and build up tension. After too much tension builds, the plates “snap” causing earthquakes

21. Divergent Boundaries When two plates separate
Most common on ocean floor
Creates Mid-Ocean Ridge

22. Divergence Forms New Ocean Floor

23. Convergent Boundaries
Three Main Types:
Continental & Oceanic- causes deep ocean trench and land volcanoes Ex: Andes Mountains
2. Continental & Continental- causes large land mountain ranges Ex: Himalayan Mountains
3. Oceanic & Oceanic- causes deep ocean trench and island arc (chain of volcanic mountains) Ex: Mariana trench and islands

24. Subduction Zone Continental + Oceanic Crust

25. Continental + Continental Crust

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

27. Subduction Zone Oceanic + Oceanic Crust

29. Some videos for your viewing pleasure…
Plate Movement:
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San Andreas Fault:
een

30. Exit Ticket
1. Arrows in the block diagram below show the relative movement along a tectonic plate boundary. What is this type of plate boundary called?
transform plate boundary
convergent plate boundary
divergent plate boundary
subduction plate boundary

31. Exit Ticket
2. When two tectonic plates collide, oceanic crust usually subducts beneath continental crust because oceanic crust is primarily composed of igneous rock that is:
thin and less dense
thick and less dense
thin and more dense
thick and more dense

32. Exit Ticket
3. The block diagram below shows the boundary between two tectonic plates. Which type of plate boundary is shown?
divergent
transform
convergent
complex

33. Exit Ticket 4. The Himalaya Mountains were formed in a collision at a:
divergent boundary
convergent boundary
transform boundary
fracture zone

34. Exit Ticket
5. In which Earth layer are most convection currents that cause seafloor spreading thought to be located?
crust
outer core
asthenosphere
inner core

35. Earthquakes Worldwide
Tectonic Plates
Active Volcanoes
Earthquakes Worldwide