Layers of the Earth

Crust Crust – outermost layer of the Earth Ranges from 5km – 100km thick

Crust 2 Types of Crust 1) Continental Crust 2) Oceanic Crust Granite very thick (averages 30 km) Lower density 2) Oceanic Crust Basalt Relatively thin (5 – 8 km) Found on the ocean’s floor Higher density

Mantle Mantle – layer of the Earth between the crust and the core Extremely thick ~2,900km Contains 67% of the Earth’s mass Convection currents are found here

Convection Currents Convection currents are caused by the very hot material at the deepest part of the mantle rising, then cooling, sinking again and then heating, rising and repeating the cycle over and over.

Lithosphere Includes the rigid layer of the Earth. Composed of the crust and the very uppermost part of the mantle. Broken into blocks called tectonic plates

Asthenosphere below the lithosphere. softer and can bend like plastic (jello like). The lithosphere (tectonic plates) floats on the asthenosphere.

Core Core – mostly made up of iron and nickel Extends to the center of the Earth 33% of Earth’s mass

Outer Core & Inner Core Outer Core – liquid layer Inner Core – solid, dense center Is solid due to extreme pressure

Brainpop http://www.brainpop.com/science/earthsystem/earthsstructure/