Inside the Earth

The Composition of Earth• The Earth is divided into three

layers…

• The crust, mantle, and the core based on what each one is made up of.

• The lightest materials make up the outer layer, the densest materials make up the inner layers.

Composition (What it is made of)

• Crust

• Mantle

• Outer

• Core

Inner Core

The Crust• Outer layer

• 5-100 km thick

• 2 types of crust

–Oceanic Composed of basalt (rock)

–Continental composed of granite (rock)

Oceanic vs. Continental Crust• Composition:

granite (Rock)• average thickness

of 40 km.• Temperature= air

temperature to 870°C

Composed of Granite

• Composition: basalt (rock)

• 5-10 km thick • Temperature=

water temperature to 870°C

Composed of Basalt

Oceanic and Continental Crust

Calculating Density…

• Density = Mass / Volume

The Mantle• Composed of mostly

of iron and magnesium

• Thickness: 1800-2900 km thick

• State of matter: upper mantle is solid, lower mantle is liquid

• Temp =870-3700°C

• Density= more dense than the crust

The Mantle…• It is made up mostly of iron and

magnesium, which is very dense. The mantle acts like silly putty or laffy taffy.

• The density ranges from 3.4-4.4 g/cm3

• Temperature=870-3700°C• Lots of Pressure!

The Outer Core• It is composed of

liquid iron and nickel, which causes Earth’s magnetic field.

• It is 2,270 km thick• It is a liquid• Temp: Up to

6,000°C• Density=more dense

than the mantle

Inner Core• Composed of iron and

nickel

• 1216 kilometers thick

• Solid (Due to Pressure)

• Temperature=6,000-7200°C Hotter than the Sun!!

• Density most dense layer of them all

Earth’s Layers

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

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

Do you Remember?• 1. What is the difference between

continental and oceanic crust?

• 2. Which layer is the hottest?

• 3. Arrange Earth’s layers from hottest to coolest.

• 4. What layer is the least dense?

• 5. A drilling rig can dig down 6 kilometers. What layer of Earth would you more than likely be in?

Physical Structure of the Earth(5 Layers)

• Lithosphere- crust and rigid outer layer of mantle (upper mantle)

• Asthenosphere- solid rock that flows slowly (like hot asphalt, apart of mantle)

• Mesosphere-The strong, lower part of the mantle.

• Outer Core- liquid layer

• Inner Core- solid, very dense

Tectonic Plates• Earth’s crust is broken into about 19

pieces

• These plates move on top of the asthenosphere