Across
- 2. Ancient landmass made up of all the continents that began to break apart about 200 million years ago.
- 3. It is a layer at the top of the Earth's surface.
- 6. where new crust is generated as the plates pull away from each other.
- 8. A person who introduced a plate tectonic theory.
- 12. States that Earth's crust and upper mantle are broken into plates.
- 15. The weight of a subducting plate helps pull the trailing lithosphere into subduction zone.
- 16. Changes in Earth's magnetic field over geologic time.
- 17. a vent in the earth's crust through which lava, steam, ashes, etc., are expelled
- 19. It is the rigid, outermost shell of a rocky planet
Down
- 1. Device used to map the ocean floor that detects small changes in magnetic fields.
- 4. where crust is neither produced nor destroyed as the plates slide horizontally past each other.
- 5. The weight of the uplifted ridge is thought to push an oceanic plate toward the trench formed at the subduction zone.
- 7. Hess's theory that new ocean crust is formed at mid-ocean ridges and destroyed at deep-sea trenches
- 9. Study of Earth's magnetic record using data gathered from iron-bearing minerals in rocks.
- 10. It is a layer under the crust.
- 11. a series of vibration induced in the Earth's cru
- 13. Wegener's hypothesis that Earth's continents were joined as a single land mass about 200 million years ago.
- 14. process by which one tectonic plate slips beneath another tectonic plate.
- 18. Line on a map that connects points of the same age.
- 20. It is hot regions of Earth's mantle where high-temperature plumes of mantle material rise toward the surface.
