1. The Theory of plate tectonics, Plate Movement, & Hot Spots

2. Do Now
Landscapes are constantly changing and Islands are constantly being newly formed.
Why is this happening?
How do you think this occurs in nature?

3. Heat Transfer & Melting the Mantle Convection  Plate Movement
Intraplate  Hot Spots

4. The Plate Tectonic Theory & Location of the Plates

5. Theory of Plate Tectonics
The theory that states that Earth’s lithosphere and crust are divided into plates, most of which are in constant motion.
The plates glide across the underlying asthenosphere due to frictional coupling caused by convection heat transfer.
Continents are located on tectonic plates and move around with them.

6. Know and be able to locate all plates in red- 7 major and 2 minor
Tectonic Plates
7 Major (Larger) Plates
North American
South American
Eurasian
Indo-Australian
Antarctic
African
Pacific
Minor (Smaller) Plates
Nazca
Philippean
Cacos
Arabian
Juan de Fuca
Caribbean
Scotia
Know and be able to locate all plates in red- 7 major and 2 minor

7. How were Plate Boundaries Identified
How were Plate Boundaries Identified? Scientist plotted the occurrences of earthquakes and volcanic eruptions around the world
Earthquakes Worldwide
Tectonic Plates

8. HES

9. Earth’s Lithospheric Plates

10. Plate Movement and Melting the Mantle via Convection

11. Plate Boundaries and Movement
The area where two plates meet is called a plate boundary.
90% of geologic activity at the surface of the Earth takes place at the boundaries between tectonic plates.
Three main types of plate boundaries:
Convergent
Divergent
Transform

12. Convergence- 3 Types

13. Continental + Continental Convergence (Collision)
Himalayan Mts

14. Continental + Oceanic Crust (Subduction)
Cascade Mts
Andes Mts

15. Subduction followed by Collision  Himalayas
Subduction (o-c convergence)
Subduction leading to collision (convergence) and formation of Himalayas
Animation of Himalayas Formation:
70 my in 2 min -The Himalayas Forming:

16. Oceanic + Oceanic Crust (Subduction)
Japanese Islands
Indonesian Islands

17. NOTE to reiterate the formation of magma via subduction:
The subduction slab dehydrates and releases that water to the mantle, lowering the mantle melting temperature.

18. Divergence (Decompression)
Separation of 2 plates
“Seafloor spreading”
Mid-Ocean Ridges (MOR)
Forms new ocean crust
Mid-Atlantic Ridge which is visible on land in Iceland
Continental rifts (East Africa)

19. Mid-Ocean Ridge System

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

21. Transform Boundaries Occurs at divergent boundaries
2 plates slide past each other
This sliding is not smooth. Plates lock and build up tension.
Then the plates “snap” and release that energy  earthquake!

22. Animation of transform, divergent, and subduction boundaries: http://tinyurl.com/pbxdt

23. Intraplate Melting of the Mantle via Hot Spots

24. Mantle Plumes (Hotspots)
Individual column of magma that rises up and punches through the lithosphere
Forms chains of volcanoes as a plate
moves over the hot spot
~100 Hot Spots
10% of heat transfer
Decompression melting (like divergence)

26. Hotspot volcanism: http://tinyurl.com/y6dyd6
Which mountain
Is oldest?
Hotspot volcanism:

27. THINK!
The expression of tectonic plate and hot spot activity at the surface includes the formation of what features and results in what natural disasters?
All tectonic plate and hot spot activity results in Earthquakes.
What is an earthquake?
Where would you expect to have deep vs. shallow earthquakes? Explain.
Volcanism occurs where you have melt mechanisms at play.
What is a volcano?
What are the 2 melt mechanisms?
Do they form new continental or oceanic crust?
Do you think the intensity of the volcanic eruption is similar for each melt mechanism?

28. Diagram plate movement and hot spot activity on the “Earths Interior” worksheet

29. Practice Worksheet

30. Self-Check: Do you KNOW about plate movement and hot spot activity?
You should be able to address the following:
Name and describe the three types of plate boundary movement. Be able to provide examples.
Describe frictional coupling as it applies to plate movement.
What is a mantle plume?
What are the primary melt mechanisms in the mantle?
What topographic features result from plate movement and hot spot activity? Be specific- demonstrate your knowledge.
What natural disasters result from plate movement and hot spot activity? Be specific- demonstrate your knowledge.
Compare and contrast earthquake activity from divergence vs. subduction.
Compare and contrast volcanism from subduction vs. hot spots.