| A | B |
|---|
| seismic waves | Energy waves produced by earthquakes |
| mantle | Middle layer of the earth made of hot, solid rock |
| Basalt | Extrusive igneous rock which makes up the oceans crust. |
| Lithosphere | Rigid layer of the Earth consisting of the crust and the upper mantle. |
| Asthenosphere | Soft layer of the upper mantle |
| Convection Currents | Transfer of heat within a fluid. |
| Outer Core | Layer of molten metal that surrounds the inner core. |
| Inner Core | Dense ball of solid iron and nickel in the center of the Earth. |
| radiation | Transfer of energy through space. |
| Conduction | Heat transfer within a material or between materials that are touching. |
| Continental Drift | Theory that continents moved slowly over time. |
Pangaea,  | Wegener's theory of a supercontinent where all of the continents were once together. |
| fossil | Trace of an ancient organism that is preserved in rock. |
sea-floor spreading,  | Spreading of seafloor on both sides of a mid-ocean ridge. |
| Sonar | Device that bounces sound waves off underwater objects and then records their echoes. |
| Subduction | Process by which ocean floor sinks beneath a dep-ocean trench and back into the mantle. |
| Rift Valley | A deep valley which forms along divergent plate boundaries. |
| Divergent boundary | The place where two plates move apart. |
| Convergent boundary | The place where two plates come together. |
| Transform boundary | Place where two plates slip past each other, moving in opposite directions. |
