Vocabulary:
Plate Tectonics
Vocabulary Word
1.
Tectonic/Crustal plates
Definition
-Large, moving pieces of Earth’s lithosphere that rest on the asthenosphere
-Commonly carries both oceanic and continental crust
2.
Continental Drift
-A hypothesis made by Alfred Wegener in 1912
-Continents were once joined together but moved apart over time
3.
Pangaea
-Supercontinent that included all of the landmasses on Earth; began
breaking apart about 200 million years ago
4.
Plate Tectonics
-Theory that pieces of Earth’s lithosphere are in constant motion, driven by
convection currents in the mantle
5.
Divergent Boundary
-Boundary along which two tectonic plates move away from each other
-The sea floor spreads apart and new crust is formed
6.
Convergent Boundary
-Boundary along which two tectonic plates move toward each other
-Characterized by subduction or continental collision
-Crust is usually destroyed
7.
Transform Boundary
-Boundary along which two tectonic plates scrape past each other
-Characterized by earthquakes; crust isn’t created or destroyed
8.
Hot spot
-An area where a column of hot material rises from deep within the
mantle.
surface
9.
10.
Subduction
Rift valley
-Lithosphere above is heated, causing volcanic activity at the
-The process by which denser crust sinks beneath less dense crust
-A deep valley formed as tectonic plates move away from each other at a
divergent boundary
11.
Mid-ocean ridge
-An underwater mountain range where new ocean crust is formed by
volcanic activity along a divergent boundary
12.
Ocean basin
-A great depression occupied by the ocean on the surface of the
lithosphere