Across
- 4. ridge An undersea mountain chain where new ocean floor is produced; a divergent plate boundary.
- 5. Breaks in Earth's crust where rocks have slipped past each other.
- 8. current the movement of a fluid, caused by differences in temperature, that transfers heat from one part of the fluid to another
- 10. boundary A plate boundary where two plates move past each other in opposite directions-like the San Andreas in California
- 13. core A layer of molten iron and nickel that surrounds the inner core of Earth
- 14. The direct transfer of heat from one substance to another substance that it is touching.
- 15. boundary A plate boundary where two plates move away from each other.
- 17. drift The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
- 18. trench a deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle
- 22. boundary A plate boundary where two plates move toward each other.
- 23. core A dense sphere of solid iron and nickel at the center of Earth
- 24. The transfer of heat by the movement of a fluid
- 27. waves vibrations that travel through Earth carrying the energy released during an earthquake
- 28. tectonics The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle.
- 29. A dark, dense, igneous rock with a fine texture, found in oceanic crust
Down
- 1. supercontinent
- 2. A trace of an ancient organism that has been preserved in rock.
- 3. the transfer of energy through space
- 4. The layer of hot, solid material between Earth's crust and core.
- 6. Mass per unit volume
- 7. A usually light colored igneous rock that is found in continental crust
- 9. The layer of rock that forms Earth's outer surface.
- 11. a device that bounces sound waves off underwater objects to map the ocean floor
- 12. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.
- 16. valley A deep valley that forms where two plates move apart
- 19. A section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust.
- 20. The soft layer of the mantle on which the tectonic plates move
- 21. the rigid outer part of the earth, consisting of the crust and upper mantle.
- 25. spreading The process by which molten material adds new oceanic crust to the ocean floor
- 26. theory a well-tested concept that explains a wide range of observations