Earth Systems

crust

Earth's outermost layer.

continental crust

The part of Earth's crust that makes up the landmasses and is composes mostly of granite.

granite

The most common type of rock that makes up continental crust.

oceanic crust

The part of Earth's crust that makes up the seafloor and is comprised mostly of basalt.

basalt

The most common type of rock that makes up oceanic crust.

mantle

The thickest layer of the Earth that lies between the crust and outer core.

outer core

A liquid layer of the Earth located between the mantle and inner core.

inner core

The solid, innermost layer of the Earth.

lithosphere

The Earth's crust and upper portion of the mantle.

asthenosphere

The soft layer of the mantle where convection occurs and on which the tectonic plates move.

magma

Molten rock located beneath the Earth's surface.

continental drift

The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations.

Alfred Wegener

A German scientist who proposed the theory of continental drift

pangaea

The name of the single landmass that broke apart 200 million years ago and gave rise to today's continents

tectonic plates

Large movable plates under the Earth's surface.

convection currents

The process in Earth's mantle that scientists believe is driving the movement of the plates due to the heating and cooling of magma.

plate boundary

the place where two tectonic plates meet