click below
click below
Normal Size Small Size show me how
Inside the Earth
| Term | Definition |
|---|---|
| Crust | The outermost layer of the Earth. |
| Mantle | The layer of the Earth between the crust and the core. |
| Core | The layer of the Earth that extends from below the mantle to the center of the Earth. |
| Lithosphere | The solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle. |
| Asthenosphere | The soft layer of the mantle on which the tectonic plates move. |
| Mesosphere | The strong, lower part of the mantle between the asthenosphere 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 that the continents once formed a single land mass, 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 Earthâs outermost layer, called 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 squeeze an object. |
| Tension | Stress that occurs when forces act to stretch an object. |
| Folding | The bending of rock layers due to stress. |
| Fault | A break in a body of rock along which one block slides relative to another. |
| Uplift | The rising of regions of the Earthâs crust to lower elevations. |
| Subsidence | The sinking of regions of the Earthâs crust to lower elevations. |