1. Plate Tectonics and the Ocean Floor
© 2011 Pearson Education, Inc.

2. Which is Which?

4. Continental Drift
In 1912 Alfred Wegener proposed that millions of years ago all of the continents were part of one supercontinent called Pangaea.

5. Evidence for Continental Drift
Wegener proposed Pangaea – one large continent existed 200 million years ago
Panthalassa – one large ocean
Noted puzzle-like fit of modern continents

6. Evidence for Continental Drift
Matching sequences of rocks and mountain chains
Similar rocks on different continents

7. Evidence for Continental Drift
Same fossils found on continents that today are widely separated
© 2011 Pearson Education, Inc.

8. At first the hypothesis of Continental Drift was not accepted.
Now, widely accepted, it has become incorporated into the Theory of Plate Tectonics.

9. Continental Drift

10. Theory of Plate Tectonics
Lithosphere – tectonic plates that float on ductile asthenosphere
Large scale geologic features occur at plate boundaries
An early Theory?

11. Plate Tectonics: A new way of thinking
Paradigm Shift: Change in world view
Shape of the Earth
Continental drift
Sustainability (?)
The theory of Plate Tectonics caused a Paradigm shift in how the Earth moves and how new crust is created.

12. Marie Tharp Mapped the Ocean floor.
In 1952 she identified a key feature of the ridge dividing the North Atlantic. This was a controversial assertion during the decades-long debate over continental drift.
By the time Marie retired in 1983, plate tectonics had been widely accepted; she had witnessed, and help to foster, a complete transformation of her field.
complete transformation of her field.

13. Plate Tectonic Processes

14. Plate Tectonics

15. A Little Lesson on Longitude and Latitude

16. Latitude & Longitude
Latitude is distance north or south of the Equator and longitude is distance east or west of the prime meridian.
Both are measured in terms of the 360 degrees (symbolized by °) of a circle. Imaginary lines of latitude and longitude intersect each other, forming a grid that covers the Earth and helps us locate points on it.

17. Latitude
The Equator is the line of 0° latitude, the starting point for measuring latitude.
The latitude of the North Pole is 90° N, and that of the South Pole is 90° S.
The latitude of every point in between must be some degree north or south, from 0° to 90°.

18. Longitude
The line which runs through Greenwich in  London is called the Greenwich Meridian or Prime Meridian. 
The Prime Meridian is 0° longitude. •The Earth is then divided into 180°east and 180°west. •The International Date Line lies at  °east/west

19. Longitude & Latitude Assignment
Complete the Longitude & Latitude Assignment.
Due to be passed in:
Wednesday September 9th