Inside the Earth

Chemical Composition(What it is made of)

• Crust

• Mantle

• Core

The Crust• Outer layer• 5-100 km thick• 2 types of crust

– Oceanic• very dense,

made of basalt,about 3 – 5 miles (8km)thick

– Continental• less dense,

made of granite,about 25 miles(32km) thick.

• Made of: aluminum, calcium, iron, magnesium, oxygen, potassium, silicon, sodium

Oceanic and Continental Crust

The Mantle• Middle layer• Very thick layer,

extends from 200 km to 3000 km; approx. 2,900 km thick

• The largest layer• A dense, hot layer of

semi-solid rock• Made of: silicon,

iron, oxygen, magnesium

• 80% of volume, 68% of mass

The Core

• Made mostly of iron and some nickel

• 1/3 of the earth’s mass

• Very hot

• A ball of very hot, dense metals

The Core

Core, which is nearly twice as dense as the mantle because it composition is metallic (iron-nickel alloy) rather than stony. The core is made up of two parts, a thick liquid center and a thick solid inner core. The liquid core spins, creating the Earth’s magnetic field.

Physical Structure of the Earth(5 Layers)

• Lithosphere- rigid outer layer (crust)

• Asthenosphere- solid rock that flows slowly (like hot asphalt)

• Mesosphere- middle layer

• Outer Core- liquid layer

• Inner Core- solid, very dense

Lithosphere

• The crust and upper layer of the mantle

• The lithosphere is– rigid and solid, but also brittle– broken into pieces called plates that are

moving– where

volcanoesform

Asthenosphere

• The semi-solid, semi-liquid in the mantle

• Flows like hot asphalt under a heavy weight (called plasticity)

• 700 km deep

• Convection currents occur here, that cause the plates of the lithosphere to move

Mesosphere

• Most of the mantle

• A very thick, semi-liquid layer

Outer Core

• Liquid iron & nickel

• Extremely hot (3800° C)

• 2200 km thick

Inner Core

• The hot metals are under so much pressure they are a solid

• Solid iron & nickel• 5000° C• Diameter of 2400 km

Earth’s Layers

• How are the earth’s layers similar to an egg?

• Shell=crust• Egg white=mantle• Yolk=core