Plate tectonicts

2. Occurs when one plate sinks beneath another, often creating a trench and volcanic activity.
4. Boundary Where two plates move toward each other.
8. Ridge A long, underwater mountain chain, typically a divergent boundary where new oceanic crust is formed.
10. Building Occurs when continental plates collide and are uplifted.
11. Spreading Creates new oceanic crust at mid-ocean ridges as plates diverge.
12. An opening in the Earth's crust through which molten rock, ash, and gases escape.
13. plates large slabs of the lithosphere that move on the asthenosphere)
14. Boundary Where two plates slide past each other horizontally.
16. Boundary Where two plates move away from each other.
17. The supercontinent that existed millions of years ago, from which the current continents broke apart and drifted.
18. Trench A very deep valley on the ocean floor, usually formed at a subduction zone where an oceanic plate sinks beneath another.
19. the rigid outer layer of the Earth)

1. the soft pliable layer of the mantle)
3. Currents The circular motion of the mantle's hot, less dense material rising and cooler, denser material sinking, which drives the movement of tectonic plates
5. The rigid outer part of the earth, consisting of the crust and upper mantle, which is broken into tectonic plates.
6. A break in the Earth's crust where movement occurs, which can cause earthquakes.
7. The soft, ductile layer of the upper mantle on which the tectonic plates move.
9. Drift The theory that the continents were once joined and have since drifted apart.
15. of Fire A major belt of volcanoes and earthquakes surrounding the Pacific Ocean
20. Tectonics The scientific theory that Earth's outer shell is divided into several plates that glide over the mantle.
21. A valley formed on land when continental plates pull apart.