Across
- 7. large volcanoes that form when different eruptions make layers
- 9. lava flow with a smooth, ropy surface
- 10. a break in the Earth's crust
- 12. rising and falling of heat in the mantle
- 15. solid, outermost layer of Earth
- 16. point on Earth's surface directly above the focus
- 18. molten metal, iron, and nickel, creates magnetic field
- 21. low, steep volcano, most common
- 22. place inside the Earth where an earthquake begins
- 24. volcano formed when flows of lava form gently sloping, wide sides
- 25. rigid, means "stone," uppermost mantle
- 26. edge of the Pacific plate where most earthquakes and volcanoes occur
Down
- 1. Alfred Wegener's theory that continents are moving
- 2. weak and soft, below lithosphere
- 3. dense, fast-moving flow of solidified lava pieces, ash, and gases
- 4. middle layer of Earth, divided into three parts
- 5. solid, below asthenosphere
- 6. lava flow with a rough, rubbly surface
- 8. Harry Hess's theory that the floor of the sea is spreading, causing continents to drift
- 11. force that acts on rock to change its shape or volume
- 13. when a volcano collapses on itself; can become a lake
- 14. innermost layer of Earth, divided into two parts
- 17. a weak spot in the Earth's surface where molten material comes to the surface
- 19. series of waves caused by earthquakes or volcanoes
- 20. solid, dense, extreme pressure, innermost layer of Earth
- 23. when the ocean floor sinks beneath the continental crust at trenches