Sea Floor Spreading

Today you will study sea floor spreading. Put all these questions in an Appleworks document and answer them by going to the links.

1. Go here and watch the animation. Take four pictures (Apple-Shift-4), one at 180 Million years ago, one at 100 Million years ago, one at 40 million years ago, and one at zero years ago (now). Explain in a sentence how South America and Africa used to be and how they moved.

2. GO HERE, read the first three paragraphs and watch the sea floor spreading animation by pressing the play button.

3. Explain what happens to the magma (press the magma button to see an arrow).

4. Click on the word "divergent" and write down the definition of divergence.

5. Explain what happens to the two plates at a divergent boundary.

6. The Earth's magnetic field reverses, where north becomes south and south becomes north. GO HERE, read the page and play with the animation.

7. Explain what rocks on the seafloor, on either side of a mid-ocean spreading ridge do.

8. Using the animation, the red arrow on the compass is the north pole. What direction was North five million years ago? What direction was north three million years ago? What direction is north now (zero million years ago)?

Put your document in the Sea Floor Spreading folder.