1. The Earth’s
Layers
Scientists have spent many years determining what is inside the earth. Geologists can’t use x-rays to see inside the earth or dig a hole deep enough to explore what is deep inside the Earth. They have used instruments to measure earthquake waves move through the Earth. These waves pass through different materials at different rates. By analyzing earthquake waves, geologists have theorized that the interior of the earth consists of layers.

2. Inside Our Earth Crust Mantle Outer Core Inner Core
Scientists have identified three main layers. At the center of the earth, is the core which is 750 miles in diameter. Next we find the outer core at 1,430 miles thick. Then we have the mantle at 1,800 miles. Finally, we have the earth’s crust which is very a thin layer in comparison to the rest of the earth at miles.
Inside Our Earth

3. Composition of the Earth’s Layers
The crust is made of soil,
water and rock.
The mantle is hot part
melted and part solid
iron and magnesium.
The outer core is
made of hot liquid
nickel and iron.
The earth’s crust is composed of minerals. This is where we live and where the oceans and mountains are. Underneath the soil and water, is rock. Under the crust, is the mantle of the earth which is made of thick material. The mantle is made of hot, part melted, part solid rock. It is composed of iron and magnesium. This hot melted rock is so deep that we usually do not worry about it, however, sometimes it forces its way through the mantle to the surface of the earth as lava form a volcano. The outer core is composed of liquid nickel and iron, two metals that sank slowly through the mantle to collect at the center of the earth. The inner core is made of solid nickel and iron. Although it is hot enough to be a liquid, the pressure at the center of the earth squeezes metals into a solid.
The inner core
is made of solid nickel and iron.
Composition of the Earth’s Layers

4. #2 The earth is layered with
CORE metallic, inner core is solid, outer core is molten
MANTLE solid but is hot enough to flow
LITHOSPHERE made of crust and uppermost mantle

5. Crust Continental Crust (thicker & lighter)
- Oceanic Crust (thinner & more dense)

6. #9 Why is there a different density between the types of crust?
The oceanic crust is squeezed by the immense pressure of the oceans above and the granite is transformed into basalt.

7. Crust Continental Crust is made of Granite
Oceanic Crust is made of Basalt

8. #3 Each layer differs in composition, density, and temperature.

9. Inner Core
Layer: CORE – Inner Composition: Nickel and Iron (solid) Density: 12.6 – 13.0 g/cm3 Temperature: 5000 degrees Celsius

10. Outer Core
Layer: CORE – Outer Composition: Nickel and Iron (liquid) Density: 9.9 – 12.2g/cm3 Temperature: degrees Celsius

11. Mantle
Layer: MANTLE - Asthenosphere Composition: Silicon, oxygen, iron, & Magnesium Density: 3.3 – 5.7 g/cm3 Temperature: degrees Celsius

12. Lithosphere
Layer: Lithosphere (upper Mantle and Crust) Composition Density Temperature

13. Crust
Layer: CRUST - Continental Composition: Granite & oxygen, silicon, aluminum, calcium, iron, sodium, potassium, & magnesium Density: 3.0 – 3.3 g/cm3 Temperature: degrees Celsius

14. Crust
Layer: CRUST - Oceanic Composition: Basalt & oxygen, silicon, aluminum, calcium, iron, sodium, potassium, & magnesium Density: 2.7 – 3.0 g/cm3 Temperature: degrees Celsius