| Term | Definition |
|---|---|
| Crust | The outermost layer of the Earth |
| Mantle | The layer between the crust and the core |
| Core | |
| The central part of the Earth below the mantle | |
| Lithosphere | The solid outer layer of the Earth the consists of the crust and the rigid upper part of the mantle |
| Asthenosphere | The soft layer of the mantle on which moves the tectonic plates |
| Mesosphere | The strong, lower part of the mantle between the athenosphere and the outer core |
| Tectonic Plate | A block of lithosphere that consists of the crust and the rigid, outermost part of the mantle |
| Continental Drift | The hypothesis that states the continents once formed a single landmass, broke up, and drifted to their present locations |
| Sea-Floor Spreading | The process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies |
| Plate Tectonics | The theory that explains how large pieces of the Eartha??s outermost layer, called the tectonic plates, move and change shape |
| Convergent Boundary | The boundary formed by the collision of two lithospheric plates |
| Divergent Boundary | The boundary between tectonic plates that are moving away from each other |
| Transform Boundary | The boundary between tectonic plates that are sliding past each other horizontally |
| Compression | Stress that occurs when forces act to when forces act to squeeze an object |
| Tension | Stress that occurs when forces act to stretch the object |
| Folding | The bending of rock layers due to stress |
| Uplift | The rising of regions of the Eartha??s crust to higher elevations |
| Subsidence | The sinking of regions of the Eartha??s crust to lower elevations |
| Fault | A break in a body of rock along which one block slides relative to another |