Term | Definition |
Lithosphere | The outer part of the solid earth composed of rock essentially like that exposed at the surface, consisting of the crust and outermost layer of the mantle, and usually considered to be about 60 miles (100 kilometers) in thickness. Otherwise known as Earth |
Crust | The solid, outermost layer of the Earth, lying above the mantle. |
Mantle | The layer of the earth between the crust and the core. |
Core | The central region of the Earth; it extends fourteen hundred to eighteen hundred miles from the Earth's center. Note: The core is made primarily of iron and nickel and has two parts — an inner solid core and an outer liquid core. |
Pangea | Hypothetical land area believed to have once connected nearly all of the earth's landmasses together |
Tectonic Plate | The broken sections of solid rock. |
Plate Boundary | The region where two tectonic plates meet. |
Plate Tectonic Theory | Describes the large scale motion of Earth's lithosphere (surface). |
Continental Drift | The movement of the Earth's continents relative to each other across the ocean bed. |
Plate | One of the major pieces of solid rock that make up the Earth's upper layer. |
Continental Plate | One of the large pieces of the surface of the Earth that move separately. |
Oceanic Plate | The section of Earth's lithosphere which surfaces in the ocean basins. |
Sea Floor Spreading | Where two oceanic plates move apart and magma flows up into the space between the plates. |
Mid-Ocean Ridge | The long chains of underwater volcano mountains. |
Volcano | An opening in the Earth's surface through which magma is released. |
Earthquake | The shaking of the ground that occurs when rock in the Earth's crust breaks or slips and quickly releases pressure. |
Convergent Boundary | Forms when two plates collide. |
Divergent Boundary | Forms when two plates separate. |
Transform Boundary | Forms when two plates slide past each other. |
Asthenosphere | Hot part of the mantle directly below the lithosphere (surface). |
Fault | The break, or crack in Earth's surface along which movement occurs. |