Question

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1. hess thought that __________ was the mechanism that was causing the continents to move. 15. ________ is the study of the magnetic properties of rocks. paleomagnetism 16. true or false (circle one): earth acts as a giant magnet. 17. when magma solidifies to form rock, the iron - rich minerals align with ________. when the rock hardens, the magnetic orientation of the minerals is permanent. magnetic reversals 18. true or false (circle one): earths magnetic field has always pointed north. 19. rocks with magnetic fields that point north have normal polarity. 20. rocks with magnetic fields that point south have reversed polarity. 21. describe the pattern the scientists discovered when they placed the rocks into chronological order. ________ 22. this pattern is called the ________ why it matters: our own space shield 23. in what way does earths magnetic field protect life on earth? ________ magnetic symmetry 24. describe the magnetic patterns scientists found on the ocean floor. ________ 25. where is the only place on the sea floor that new rock forms? ________ 26. where does the new rock then move? __________

Explanation:

1. Hess proposed that mantle convection was the mechanism causing continents to move.
2. Paleomagnetism is the study of the magnetic properties of rocks.
3. Earth does act as a giant magnet, so it's True.
4. When magma solidifies, iron - rich minerals align with Earth's magnetic field and the orientation becomes permanent.
5. Earth's magnetic field has reversed in the past, so it's False that it has always pointed north.
6. Rocks with north - pointing magnetic fields have normal polarity.
7. Rocks with south - pointing magnetic fields have reversed polarity.
8. Scientists found a pattern of alternating normal and reversed polarity when rocks were placed in chronological order.
9. This pattern is called the magnetic polarity time scale.
10. Earth's magnetic field deflects charged particles from the sun, protecting life from harmful radiation.
11. On the ocean floor, there are alternating stripes of rocks with normal and reversed magnetic polarity, symmetric about mid - ocean ridges.
12. New rock forms at mid - ocean ridges on the sea floor.
13. New rock moves away from the mid - ocean ridges towards the continents.

Answer:

1. Mantle convection
2. Paleomagnetism
3. True
4. The iron - rich minerals align with Earth's magnetic field; permanent
5. False
6. Normal
7. Reversed
8. Alternating normal and reversed polarity
9. Magnetic polarity time scale
10. It deflects charged particles from the sun, protecting life from harmful radiation.
11. Alternating stripes of rocks with normal and reversed magnetic polarity, symmetric about mid - ocean ridges
12. Mid - ocean ridges
13. Away from the mid - ocean ridges towards the continents