Page 156 - Science Course 2 (Book 2)

5. Use your answers to help you explain seaf oor spreading.

Mo11-L4: Key Concept Check

Direction: Answer each question on the lines provided. Use complete sentences

1. What does normal polarity mean?

2. What does reversed polarity mean?

3. How can scientists tell when changes occur in Earth’s magnetic f eld?

4. How often do magnetic reversals occur?

5. What do Earth’s magnetic stripes indicate about ocean crust?

6. How do Earth’s magnetic signatures support the idea that continents move?

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