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 Asthenosphere | Layer of the Earth below the lithosphere |
| Compression force | Force present when two regions of rock are moving together |
| Continental crust | Thicker, less dense crust |
| Convection cells | Motion of the mantle that drives the movement of tectonic plates |
| Crust | Outer surface of the Earth |
| Epicenter | Area on the Earth's surface above the focus of an earthquake |
| Fault | Surface along which rocks break and move |
| Focus | Area below the Earth's surface where an earthquake originates |
| Inner core | Region of solid nickel and iron |
| Lithosphere | Composed of the crust and upper mantle; divided into plates |
| Moho discontinuity | Boundary between the crust and the mantle where seismic waves speed up |
| Normal fault | Rock moves down, below the fault surface |
| Oceanic crust | Dense, thin crust found; composes the ocean basins |
| Outer core | Layer of the Earth composed of liquid iron and nickel |
| Primary wave | First seismic wave to reach a seismic station |
| Reflection | Occurs when waves bounce off an object |
| Refraction | Occurs when waves bend |
| Reverse fault | Rock moves above the fault surface |
| Secondary wave | Second seismic wave to reach a seismic station |
| Seismologist | Scientist who studies earthquakes |
| Shearing force | Force that pushes rock in opposite directions |
| Strike slip fault | Location where rocks move past each other |
| Subduction | Location where one plate sinks below the other |
| Surface wave | Slowest seismic waves that cause the most destruction |
| Tension force | Force present at a normal fault where rock moves apart |
| Tsunami | Seismic sea wave |
| Upper mantle | Layer of the earth below the Earth's crust |