Earthquakes and Volcanoes

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Across
  1. 1. ridge The undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary
  2. 4. boundary A plate boundary where two plates grind against each other, moving it in different directions
  3. 6. boundary A plate boundary where two plates move away from each other
  4. 8. A soft layer of the mantle on which the lithosphere floats
  5. 11. zone The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
  6. 12. A break or crack in the Earth's lithosphere along which rocks move
  7. 14. A rigid layer made up of the uppermost part of the mantle and the crust
  8. 15. boundary A plate boundary where two plates move toward each other
  9. 17. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere
  10. 19. spreading The process by which molten material adds new oceanic crust to the ocean floor
  11. 20. The layer of rock that forms the Earth's outer surface
Down
  1. 2. currents Cause the plates to move; between the lithosphere and the asthenosphere
  2. 3. Wegener German Scientist who developed the Theory of the Continental Drift in 1912.
  3. 5. core Dense ball of solid material at the center of he Earth
  4. 7. The name of the single landmass that broke apart about 225 million years ago
  5. 9. valley A deep valley where two plates move apart
  6. 10. Drift Alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart
  7. 13. A deep canyon on the ocean floor
  8. 16. core A layer of molten iron and nickel that surrounds the inner core of the Earth
  9. 18. of Plate Tectonics Theory that pieces of the Earth's lithosphere are in motion,driven by convection currents in the mantle