1. Earth Science Objectives: Seismic Activity Map Assignment
Identify, compare, and model earth’s layers.
Identify and examine historical evidence of plate tectonics.
Identify, compare, and model plate boundaries.

2. Plate Tectonics

3. Plate Tectonic Vocabulary
Continental drift
Continental Crust
Convection
Convection Current
Convergent Boundary
Divergent Boundary
Mid-Ocean Ridge
Ocean Trench
Pangaea
Plate Tectonics
Seafloor Spreading
Subduction Zone
Mid-Atlantic Ridge

4. Crust a. What are the two types of crust?
b. Each type of crust is composed of what kind of rock?
c. Which type of crust is denser?

5. Shorelines are not true boundaries:
Continental margin –
where the ocean water
covers the continental
crust
Deep ocean basin-
covers oceanic crust
water
Continental
margin
Oceanic basin
Continental crust
Oceanic crust
The ocean water may cover miles of the continental crust

6. Earth’s Tectonic Plates
dpc.ucar.edu

7. Crust The crust is broken into separate plates.
How many plates are there?
T or F Plates are stationary.

8. Plate Movement What causes plates to move?
As the plates move, everything on them moves along with them.
Examples:
*The North American plate moves west at a rate of 4 cm per year (1.6 in./yr)
*The Pacific Ocean plate moves northward at the same rate.

9. Plate Movement
Convection currents produced in the mantle cause the plates to move.
As the plates move, everything on them moves along with them.
Examples:
*The North American plate moves west at a rate of 4 cm per year (1.6 in./yr)
*The Pacific Ocean plate moves northward at the same rate.

10. PLATE TECTONICS
The continental & oceanic plates on the earth’s surface are constantly moving.
Many geologists believe that at one time all landmasses were together: supercontinent.
Also called?

11. Pangaea

15. He was a leading scientist in providing
uni-graz.at
Alfred Wegener:
He was a leading scientist in providing
evidence that continents were moving.
CONTINENTAL DRIFT THEORY:
*Continents are drifting or moving.
*Break-up of Pangaea occurred around 240 million yrs ago
* Over time continents broke up into smaller pieces and have drifted to their current location
*The continents are currently still moving

16. Alfred Wegener: Continental Drift Evidence Evidence: 1
Alfred Wegener: Continental Drift Evidence Evidence: 1. Similarities in coastlines 2. Similarities in fossil records 3. Similarities in rock

17. Continental Drift: Evidence
180 million years ago, Pangaea began to break up into separate continents.
Provided evidence of ancient animal and plant remains from South America, Africa, India, and Australia that were very similar.

18. Wegener’s Continental Drift Theory
What problem or concern do you think other geologist had with Wegner’s theory?
Could not provide direct evidence that the continents were moving.

19. Continental Drift Theory: Conclusive Evidence
Where?: Under the Atlantic Ocean
What? Mountain Range
Mid Atlantic Ridge
the ridge looks like a mountain with a valley running down the center
Who? Harry Hess
velikovsky.info

20. Aerial picture of the Mid-Atlantic Ridge

21. Harry Hess’ Important Observations
Studied rock data from the Mid Atlantic Ridge
Found in the center of the ridge is a crack or rift.
Magma would flow up through this rift

22. Harry Hess Conclusion:
The ocean floor was moving away from the ridge on both sides.
As it moved away, it was replaced by rising magma that cooled and solidified into new rock.
He called this process: Sea Floor Spreading

23. Sea Floor Spreading
Thingvellir, the spreading zone in Iceland between the North American (left side) and Eurasian (right side) tectonic plates. January 2003.

24. Hess’ Later Observations and Conclusions
Continued to support sea floor spreading.
Evidence by further studying the structure, properties, and age of the rock around the Mid-Atlantic ridge.

25. Scientific Evidence is Dynamic
Scientific evidence presented to the public is only established after years of sound research in the hands of many scientists. Despite this truth, scientists continue to test these facts as technology advances. Homework: Read and annotate the article “ UCLA scientist discovers plate tectonics on Mars”. Explain with three supporting facts from this article why the statement above is necessary for science to remain beneficial to humanity.

26. Bell Ringer: Plate Tectonics
1. Identify the 4 layers of the earth and what state of matter (solid or liquid) they are in. 2. Which layer(s) is/are responsible for the magnetic field around the earth. Explain your answer. 3. What is plate tectonics? 4. What indirect evidence did Wegener have to hypothesize his continental drift theory? 5.What direct evidence did Hess have to conclude from his research seafloor spreading? 6. What causes plates to move?

27. Plate Boundaries Plate boundaries are where two plates meet.
What type of plates can meet?
There are 3 types of plate boundaries:
1. divergent boundaries
2. convergent boundaries
3. transform boundaries

28. Earth’s Tectonic Plates
dpc.ucar.edu

29. Divergent Boundaries
What are divergent boundaries?

30. Divergent Boundaries Iceland is along a divergent boundary.
The North American Plate & the Eurasian Plate

31. Thingvellier,Iceland

32. Divergent Boundaries
Mid-Atlantic Ridge: Extends from the Arctic Ocean to beyond the southern tip of Africa & moves 2.5cm per year.

33. Divergent Boundaries:
African Rift Valley – east African Plate is spreading & has torn Saudi Arabia away from the rest of the African continent forming the Red Sea

34. Convergent Boundaries
What is a convergent boundary?

35. Convergent Boundaries
There are three types of convergent boundaries?
1. Oceanic-oceanic
2. oceanic-continental
3. continental-continental
nature.nps.gov

36. Convergent Boundaries Continental Convergence:
Continental convergence form mountain ranges
Example: Himalayan Mountains formed by the convergence of the Indian and Eurasian Plates.
nature.nps.gov
nature.nps.gov

37. Himalayan Mountain Range
destination360.com
geography.howstuffworks.com

38. Convergence Boundaries:
Continental and Oceanic Convergence:
Create trenches and volcanic mountains
One crust subducts under another.

39. Aleutian Islands
Pacific Plate & North American Plate form the Aleutian Islands in the Pacific Ocean off the northeast coast of Siberia

40. Andes Mountains
Nazca Plate & South American Plate form the Andes Mountains on the western border of the South American continent
geo1202peru.blogspot.com

41. Convergent Boundaries: Oceanic Convergence
Creates trenches, volcanic islands, and volcanic island arcs
Subduction zone

42. Mariana Trench Located in the Pacific Ocean near Japan.
Created by ocean-to-ocean subduction. -Phillipine Plate is subducting under the Pacific Plate

43. Transform Boundaries
What is a transform boundary?

44. Transform Boundaries Create Earthquakes
The Pacific Plate and the North
American Plate slide past each
other.
San Andreas Fault
By Robert E. Wallace, USGS

45. Plate Tectonics Homework due Wednesday:
Complete sea floor spreading questions.
Complete questions from plate tectonic worksheet.
Continue to record seismic activity.
Heads-Up:
Quiz tomorrow over Earth’s Layers/Plate Tectonics
Test on Monday: Earth’s Layers and Plate Tectonics

46. Sea Floor Spreading Model
Use the picture below to help understand the sea floor
spreading model you made last week.
What kind of boundary is represented at #1? (slit?)
What kind of boundary is represented at #2? (slit?) 1. 2.

47. Plate Tectonics Objectives: Sea Floor Spreading Model qts. due
Plate Tectonic Map qts.
Impacts of Plate Tectonics (video/text)
Plate Tectonic Gallery Walk
Plate Tectonics on Mars article
Study Guide

48. What does Plate Tectonics Impact?
Read pg. 257 and record in your notes the following:
* What is effected by plate tectonics?
*How is it effected by plate tectonics?
* Why is it effected by plate tectonics?

49. Plate Tectonics How does it affect climate?
* Changed the climate over the last 250 million years by constantly creating geological processes (volcanoes;earthquakes) that produced heat and chemicals in the atmosphere that would promote and support life. Climate keeps most water from freezing.
How does it affect life?
Plate tectonics promotes diversity among animals by causing isolation due to geographical formations (mountains).

50. Plate Tectonics on Mars
Annotate and write a descriptive summary about the article, “UCLA scientist discovers plate tectonics on Mars.”
Due:

51. Earth Science Homework: Plate Tectonic Map article summary. Due Monday
Work on study guide. Due Tuesday.
Seismic Activity Map- if not recorded data daily.
Test:
Tuesday, Feb. 5th

52. Plate Tectonic Map Qts.
dpc.ucar.edu

53. Earth’s Tectonic Plates
dpc.ucar.edu

54. After Test Turn in the following: *Plate Tectonics Map Activity w/map.
*Study Guide (optional)
*Sea Floor Spreading for partial credit
*Plate Tectonic articles for partial credit
Pick-up:
*Earthquake Worksheet. Due Monday
*Seismic Activity Map is also due Monday