| A | B |
|---|
| ASTHENOSPHERE | fluid layer of the mantle on which the crust floats |
| CRUST | the thin and solid outermost layer of the earth above the mantle |
| INNER CORE | the dense innermost layer of earth composed of solid iron and nickel. |
| MANTLE | the layer of the earth between the crust and the core |
| LITHOSPHERE | the solid, outer layer of the earth that consists of the crust and the rigid upper part of the mantle |
| OUTER CORE | the layer of earth composed of liquid nickel and iron. |
| PLATE TECTONICS | a scientific theory that explains how major landforms are created as a result of Earth’s subterranean movements |
| CRUST | least dense layer; composed mainly of oxygen, silicon, and aluminum; |
| MANTLE | contains most of the earth's mass; composed mainly of more magnesium and less aluminum and silicon than the crust |
| CORE | the central, spherical layer of the earth below the mantle; most dense layer |
| LITHOSPHERIC PLATES | A number of rigid, but moving pieces of the Earth's surface; also called tectonic plates |
| MESOPHERE | The strong, lower part of the mantle between the asthenosphere and the outer core. |
| CONTINENTAL CRUST | the earth's outer layer of rock that composes the continents |
| OCEANIC CRUST | the earth's layer of rock which composes the dense, basalt ocean floor |
| chemical composition and physical properties | The layers of Earth are based on what two sets of characteristics? |
| asthenosphere and lithosphere | What are the two layers that the upper mantle can be divided into? |
| EARTHQUAKE | convection currents originating from within the core push the hot mantle material up toward the crust |
| MAGMA | melted rock underneath the surface of the Earth |
| LAVA | melted rock on the surface of the Earth |
| SEISMEC WAVE | Vibrations that occur when an earthquake happens. |
| CONVECTION CURRENTS | Circular currents in the mantle responsible for the movement of the tectonic plates. |
| SEISMOGRAPH | An instrument that records vibrations in the ground |
| Richter Scale | A numerical scale for expressing the magnitude of an earthquake |
| FAULT | A break in a body of rock along which there is movement |
| SUBTERRANEAN | UNDER THE EARTH'S SURFACE |
| GEOLOGY | the science that deals with the earth's physical structure and substance, its history, and the processes that act on it. |
| SEA FLOOR SPREADING | when the two sides of a mid-ocean ridge move apart, leaving magma to fill the gap |
| CONTINENTAL DRIFT | the theory that the earth's continents move gradually over the surface of the planet on a substratum of magma. |
