seismic waves
Vibrations that travel through Earth carrying the energy released during an earthquake.
pressure
The force exerted on a surface divided by the area over which the force is exerted.
crust
The layer of rock that forms Earth's outer surface.
basalt
A dark, dense, igneous rock with a fine texture, found in oceanic crust.
granite
A usually light-colored igneous rock that is found in continental crust.
mantle
The layer of hot, solid material between Earth's crust and core.
lithosphere
A rigid layer made up of the uppermost part of the mantle and the crust.
asthenosphere
The soft layer of the mantle on which the lithosphere floats.
outer core
A layer of molten iron and nickel that surrounds the inner core of Earth.
inner core
A dense sphere of solid iron and nickel at the center of Earth.
radiation
The transfer of energy through space.
conduction
The transfer of heat within a material or between materials that are touching.
convection
The transfer of heat by movement of a fluid.
density
The amount of mass in a given space; mass per unit volume.
convection current
The movement of a fluid, caused by differences in temperature, that transfers heat from one part of the fluid to another.