plate tectonics

3. the idea that the continents were once fused together but slowly drifted apart over time
6. boundary where two tectonic plates move together, or converge
7. boundary where two tectonic plates move away, or diverge, from one another
8. molten mixture of rock-forming substances, gases, and water from Earth’s mantle
9. more than a dozen distinct plates that make up Earth’s surface and slowly move in different directions
12. a rating of an earthquake’s magnitude, on a scale from 0-9, based on the size if its seismic waves
13. a break in the rock of Earth’s crust or mantle
15. structure that forms when magma rises into Earth’s crust but is trapped and can’t break through to the surface, causing pressure to build over time ad finally erupt
17. one giant continent into which most or all of the continents were assembled long ago
18. a structure that forms in Earth’s crust when molten material reaches Earth’s surface
20. magma that has reached Earth’s surface
21. the condition of undisturbed sedimentary rock in which the oldest layer is at the bottom and the youngest layer is at the top

1. the area under ocean water
2. an idea that can be tested by experimentation or investigation
4. boundary where two tectonic plates move away, or diverge, from one another
5. shaking and trembling that result from tectonic plate movement
6. a type of thermal energy transfer in which differences in temperature and density of fluids make them rise and fall
10. description of a repeated pattern observed in nature, without an explanation for the pattern
11. process in which a dense plate sinks under a less dense plate and melts in Earth’s mantle
14. an explanation for why a phenomenon
16. vibrations that travel through Earth carrying energy
19. area of the mantle where hot rock rises upward