| A | B |
|---|
| Theory of Plate Tectonics | Earth's lithosphere is broken into plates in constant, slow motion, forming mountains, earthquakes, volcanoes |
| Plates | large, moving slabs of lithosphere that fit together |
| Lithosphere | rigid, solid surface layer of Earth, made of crust and upper mantle |
| Convection | heat transfer by movement in a fluid, ex: heated magma is less dense and rises, cooled magma is more dense and sinks |
| Subduction | old ocean floor sinks under another plate into asthenosphere where it turns into molten rock |
| Divergent Boundary | plates spread apart, ex: Mid-Atlantic Ridge and Great Rift Valley |
| Convergent Boundary | plates collide in 1 of 2 ways: subduction (such as formed Andes) or uplift (such as formed Himalayas) |
| Transform Fault or Strike/Slip Boundary | plates grind past each other horizontally (ex: San Andreas Fault) |
| Asthenosphere | layer of weak, hot mantle under lithosphere |
| Magma | molten rock under Earth's surface |
| Lava | molten rock at/above Earth's surface |
