Plate tectonics

2. Theory that explains why continents are slowly drifting apart.
7. Large, rigid pieces of Earth’s lithosphere that move over the mantle.
8. The theory that Earth’s crust is split into slow-moving sections.
10. The boundary where two plates slide past one another horizontally.
13. The process where one tectonic plate moves under another and sinks into the mantle.
14. The ancient supercontinent proposed by Alfred Wegener.
15. A deep valley along the ocean floor formed by subduction.

1. A chain of underwater mountains formed at divergent boundaries.
3. A rapid shaking of Earth’s crust, often along plate boundaries.
4. Name for when two tectonic plates move away from each other.
5. Mountains formed primarily where two continental plates collide.
6. What convection currents in the mantle help to move.
9. The solid outermost layer of the Earth, including the crust and upper mantle.
11. Molten rock beneath Earth’s surface; found in the mantle.
12. Deep cracks in Earth’s surface where plates meet and earthquakes can occur.