Chapter 7-1 Pgs. 166-172Chapter 7-1 Pgs. 166-172

September 23, 2015September 23, 2015

IN: Diagram (draw and label) what IN: Diagram (draw and label) what you know of the inside of the Earth. you know of the inside of the Earth.

Inside the EarthInside the Earth

Earth’s LayersEarth’s Layers

Scientists think about Earth’s layers Scientists think about Earth’s layers in two ways.in two ways.– 1. composition (what it’s made of)1. composition (what it’s made of)– 2. physical properties (how it behaves)2. physical properties (how it behaves)

Composition of EarthComposition of Earth

The lightest materials make up the The lightest materials make up the outermost layer, and the densest outermost layer, and the densest materials make up the inner layers.materials make up the inner layers.

Why do you suppose the Why do you suppose the lightest materials formed on the lightest materials formed on the

surface of the Earth?surface of the Earth?

3 Compositional Layers3 Compositional Layers

•crust•mantle•core

The CrustThe Crust

The outermost layer to the Earth.The outermost layer to the Earth.– It is the layer you live on!It is the layer you live on!

The CrustThe Crust

There are two types of crust.There are two types of crust.– 1. Continental crust1. Continental crust– 2. Oceanic crust2. Oceanic crust

Continental CrustContinental Crust Everything not covered by the ocean.Everything not covered by the ocean.• less dense less dense than the oceanic crustthan the oceanic crust• made of made of granitegranite (a rock made of (a rock made of

mostly silicate minerals).mostly silicate minerals).• ThickerThicker than oceanic crust (5-100 than oceanic crust (5-100

km)km)

Oceanic CrustOceanic Crust Everything covered by the ocean.Everything covered by the ocean. More dense More dense than the continental crustthan the continental crust made of made of basaltbasalt (a rock composed of (a rock composed of

mostly iron).mostly iron). ThinnerThinner than continental crust because the than continental crust because the

ocean pushes it down.ocean pushes it down.

The MantleThe Mantle

The layer of the Earth between the The layer of the Earth between the crust and core.crust and core.

The MantleThe Mantle

Contains most of the Earth's mass.Contains most of the Earth's mass. Made of mostly iron and magnesium.Made of mostly iron and magnesium.

The MantleThe Mantle

No one has ever seen what the mantle No one has ever seen what the mantle really looks like because it is too far really looks like because it is too far down.down.

The mantle does rise to the surface.The mantle does rise to the surface.– Tectonic forcesTectonic forces– Underwater volcanoesUnderwater volcanoes– It appears to be like the It appears to be like the

mineral olivinemineral olivine

The CoreThe Core

Extends from the bottom of the Extends from the bottom of the mantle to the center of the Earth.mantle to the center of the Earth.– Made mostly of iron and nickel.Made mostly of iron and nickel.

Divided into 2 parts.Divided into 2 parts.– Outer coreOuter core– Inner coreInner core

Outer CoreOuter Core

Liquid layer of the Earth’s core.Liquid layer of the Earth’s core.– Lies beneath the mantle.Lies beneath the mantle.

Inner CoreInner Core

The solid, dense center of our planet.The solid, dense center of our planet.

How would you graph the How would you graph the relative size of each layer of the relative size of each layer of the

Earth?Earth?

How do you suppose we know?How do you suppose we know?

http://sunshine.chpc.utah.edu/Labs/http://sunshine.chpc.utah.edu/Labs/SeismicWaves/seismic.swfSeismicWaves/seismic.swf

OUT: What are the three OUT: What are the three compositional layers of the Earth?compositional layers of the Earth?