Earth's Changing Surface

2. When one tectonic plate moves under another. Causes earthquakes.
5. The law that states that each rock layer is older than the one above it; newer rock is laid on top of older rock.
9. A volcano that has had an eruption of magnitude 8 on the Volcanic Explosivity Index.
10. The large pieces that the Earth’s lithosphere, or outermost shell, is broken up into.
11. The relatively thick part of the earth's crust that forms the large landmasses. It is generally older and more complex than the oceanic crust.
12. A long, narrow depression on the seafloor, formed through subduction.
13. When magma escapes from a vent, or opening, in Earth’s surface. Magma released from a volcano is known as lava.
14. A boundary where two plates are pushing into each other.
18. A long mountain range on the ocean floor formed by lava eruptions through Earth’s crust.
19. The movement of continents spreading apart from one another, where they once were one large landmass.

1. A large, bowl-shaped depression in the Earth’s surface filled with salty water, diverse marine life and complex topographical features.
3. The process that creates mountains through tectonic forces and volcanic
4. Boundary where tectonic plates slide alongside each other causing earthquakes.
6. Earth’s outer shell is divided into several plates that glide over the Earth’s rocky inner layer; plate tectonics is the study of that motion.
7. The sudden shaking of the ground that occurs when masses of rock change position below Earth’s
8. Boundary where two plates are moving apart from each other.
15. The part of the Earth's crust that makes up the seafloor. It's thinner and denser than the continental crust.
16. An intensely hot area in the mantle below Earth’s crust. This heat causes the mantle to melt and rise up, breaking through the crust to form a volcano.
17. The remains or imprints of organisms from earlier geological periods preserved in sedimentary rock.