7.4 Earth's Three Layers

Convection Currents

Circulation currents in the Asthenosphere causing the movement of the tectonic plates.

Core

Innermost layer of the earth made mostly of iron. Made up of the outer core and the inner core.

Mantle

Layer between the crust and the outer core that is the majority of the Earth's mass. Made of two layers Asthenosphere and Mesosphere

Physical Layers

Layers of the Earth based on physical properties - lithosphere, asthenosphere, mesosphere, outer core, inner core.

Composition Layers

Layers of the Earth based on what they're MADE of - crust, mantle, core.

Lithosphere

Outer part of the solid earth that is broken into tectonic plates.

Tectonic Plates

Pieces that make up the lithosphere (like puzzle pieces) that float on the Asthenosphere and allow continental movement.

Inner Core

The hottest and most dense innermost layer of the Earth made of solid iron and nickel. This layer stays solid due to the pressure of the layers above it.

Outer Core

The layer of the Earth below the mantle, but above the inner core - made of liquid iron and nickel.

Mesosphere

The strong, lower part of the mantle between the asthenosphere and the outer core. Made of more solid rock

Crust

The thinnest, outermost layer of the Earth made of ocean and land.

Asthenosphere

Upper part of Mantle that is semi-liquid and flows like hot asphalt allowing movement of tectonic plates.