Across
- 1. floor spreading The idea that new crust is forming at ridges in the sea floor, spreading apart the crust on either side of the ridges
- 3. The central opening in a volcanic area through which magma may escape
- 6. The point where an earthquake starts as rocks begin to slide past each other
- 8. Earth's solid, rocky surface containing the continents and ocean floor
- 9. volcano A cone formed from explosive eruptions of hot rocks followed by a flow of lava, over and over
- 13. cone volcano A steep sided cone that forms from explosive eruptions of hot rocks, ranging from particles to boulders.
- 15. A sensitive device that detects the shaking of Earth's crust during an earthquake
- 18. The sliding of a denser oceanic plate under another plate when they collide
- 19. energy Heat from below Earth's surface
- 20. tectonics The idea that Earth's surface is broken into plates that slide slowly across the
- 22. Magma that reaches Earth's surface and flows out of a vent
- 23. The amount of energy released by an earthquake
Down
- 2. Shaking of Earth's crust after the initial shaking of an earthquake
- 4. The point on Earth's surface directly above the focus of an earthquake
- 5. waves A vibration that spreads out away from a focus when and earthquake happens
- 7. A cuplike hollow that forms at the top of a volcano around the vent
- 10. volcanoes A wide, gently sloped cone forms from flows of lava
- 11. drift The idea that a supercontinent split apart into pieces, the continents, which drifted in time to their present location
- 12. horizontality The idea that many kinds of rock form flat, horizontal layers
- 14. A huge crack in Earth's crust at or below the surface, the sides of which may show evidence of motions
- 16. Hot, molten rock below Earth's surface
- 17. A very hot part of the Earth's mantle, where magma can melt through a plate moving above it.
- 21. The layer beneath Earth's crust