Inside the Earth

Looking at the Earth’s layers

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)– Continental (less dense, made of granite)

Oceanic and Continental Crust

The Mantle

• Middle layer• Very thick layer

( 2900 km)• Rock on the top• Part of the

lithosphere

The Core

• Made mostly of iron• Very hot ( 7000 °C)• Outer core is liquid

Thickness is about 2221km

• Inner core is solid. Thickness is about 1255 km radius

Earth’s Layers

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

• Shell=crust

• Egg white=mantle

• Yolk=core

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

Earth’s Spheres

The names of the four spheres are derived from the Greek words for stone (litho), air (atmo), water (hydro), and life (bio). Atmosphere

The atmosphere is the body of air which surrounds our planet. The air of our planet is 79% nitrogen and just under 21% oxygen; the small amount remaining is composed of carbon dioxide and other gasses.

LithosphereThe lithosphere is the solid, rocky crust covering entire planet.

Hydrosphere

The hydrosphere is

composed of all of the

water on or near the

earth. This includes the

oceans, rivers, lakes,

and even the moisture in

the air.

BiosphereThe biosphere is composed of all living organisms. Plants, animals, and one-celled organisms are all part of the biosphere.

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

These plates move on top of the asthenosphere