Earth's Layers Presentation

Earth Science

Sept.14th, 2010

Mrs. Harris

Today’s objectives…

• Journey to the center of the Earth!

– Looking at Earth’s interior structure– Compositional view & Structural view

• Take a guess at how many miles it is to the center of the Earth.

• Take a guess at how many miles it is to the center of the Earth.

• 20,856,000 feet (5,280 feet per mile)

• Take a guess at how many miles it is to the center of the Earth.

• 20,856,000 feet (5,280 feet per mile)

• 3,950- 3,963 miles (closer at the poles)

Compositional Layers (what it is made of)

• Crust• Mantle• Core

The Crust

• Outer layer• 5-100 km thick

– 3-62 miles

• 2 types of crust– Oceanic (very dense,

made of basalt)– Continental (less dense,

made of granite)

• What type of rock is the oceanic crust?

Oceanic and Continental Crust

The Mantle

• Middle layer• Very thick layer

• Moves by convection– (think lava lamp)

The Core

• Made mostly of iron

• Liquid outer, solid inner

• 1/3 of the earth’s mass

• Very hot

Earth’s Layers

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

• Shell• Egg white• Yolk

Structural Layers (mechanical)

• Lithosphere- rigid outer layer – Crust and upper mantle (rigid part)

Structural Layers

• Asthenosphere- solid rock that flows slowly (like hot asphalt) – Plastic-like part of the mantle– The convection part

Structural Layers

• Mesosphere- middle layer (solid)

Structural Layers• Core

– Outer core is dense, liquid iron and other metals– Inner core is dense, solid iron

2-1 Self check VERY handy

Next Class…

• Earth’s spheres and energy budget• Cycling of matter