convection The transport of heat by movement.
convection cell A circular pattern of warm material rising and cool material sinking.
continental crust The crust that makes up the continents.
core The dense metallic center of the Earth. The outer core is liquid and the inner core is
solid.
crust The rocky outer layer of the Earth’s surface. The two types of crust are continental
and oceanic.
lithosphere The layer of solid, brittle rock that makes up the Earth’s surface. The litho-
sphere is composed of the crust and the uppermost mantle.
mantle The middle layer of the Earth, between the crust and the core. The mantle is
made of hot rock that circulates by convection.
meteorite Fragments of planetary bodies such as moons, planets, asteroids and comets
that strike Earth.
oceanic crust The crust that underlies the oceans.
plate tectonics The theory that the Earth’s surface is divided into lithospheric plates
that move on the planet’s surface. The driving force behind plate tectonics is mantle
convection.
seismic waves Also called earthquake waves. Seismic waves give scientists information on
Earth’s interior.
Points to Consider
- The oceanic crust is thinner and denser than continental crust. All crust sits atop the
mantle. What might our planet be like if this were not true. - If sediments fall onto the seafloor over time, what can sediment thickness tell scientists
about the age of the seafloor in different regions? - How might convection cells in the mantle affect the movement of plates of lithosphere
on the planet’s surface?