The The Earth’sEarth’s LayersLayers

Students will … illustrate the structural layers of Earth, including the inner core, outer core, mantle, crust, asthenosphere, and lithosphere. [6.10A]

Earth’s Layers

• Each layer of the Earth has its own unique properties.

• There are three distinct layers – the crust, mantle, and core – which can then be subdivided into more layers.

• Each layer is made up of specific elements.

Simple Layers

• Crust

• Mantle

• Core

Into the Earth…

The Crust• Outermost layer• Thinnest layer and

much cooler than others

• 2 types of crust

1. Oceanic (very dense, made of basalt)

2. Continental (less dense, made of granite)

Oceanic and Continental Crust

Thinnest beneath ocean and thickest beneath mountain ranges

The Mantle

• Layer beneath crust• Middle layer• Very thick layer• Made up of more

iron and magnesium

so is very dense• Convection currents

occur in the mantle

Mantle Is Divided into …

Lithosphere• Consists of the crust and

the upper part of the mantle

• Solid and rocky• Broken into large pieces

called tectonic plates• Earthquakes can occur in

the lithosphere• Made up of elements

Oxygen and Silicon

• Beneath the lithosphere• Partially molten• The rock is pliable or

plastic-like• Rock here bends,

stretches, and flows• The tectonic plates float

on this layer

Asthenosphere

Tectonic Plates• Earth’s crust is broken into about a dozen

major plates and several minor plates

• These plates constantly move on top of the Asthenosphere

The Core

• Made up of the elements iron and nickel

• 1/3 of the Earth’s mass

• The core is larger

than Mars!

• The core is very

hot and dense

The Core is Divided Into…

Outer Core• The outer core is a liquid• The material of the outer

core is considered molten as it is extremely hot

• Less dense than the inner core

• Made up of Iron and Nickel

Inner Core• The inner core is the

most dense

• It is solid even though the temperature is very hot due to the extreme pressure

• The inner core is composed mostly of Iron

Earth’s Layers

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

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

Physical Structure of the EarthLayers Reviewed

• Crust and Lithosphere- rigid outer layer

• Mantle and Asthenosphere- solid rock that flows slowly (like hot asphalt)

• Outer Core- liquid layer

• Inner Core- solid, very dense

References

• http://geomaps.wr.usgs.gov/parks/pltec/#crust

• http://pubs.usgs.gov/gip/dynamic/dynamic.html