Bellringer : Write question and answer at the top of today’s

note page• What is the true shape of the earth?

A.Oblate spheroid

B.Slightly eliptical

C. Perfect sphere

D.Circle

Objectives• Learn about the

different layers of the Earth

Agenda• The shape of the

Earth Notes• Lab # 4: Shape of the

Earth ( 30 minutes)• Earth’s interior notes• Earth Layer Project

The Structure of Earth

http://www.youtube.com/watch?v=35UQVcY0_qw

Four Inner Layers of the Earth

The Layers of the Earth

© Copyright 2006.  M. J. Krech. All rights reserved.

The Four Layers The Earth is composed of

four different layers.

crust

mantle

outer core

inner core

The Crust

About 3-5 miles (8 kilometers) thick under the oceans (oceanic crust) and about 25 miles (32 kilometers) thick under the continents (continental crust).

The Crust

The crust is composed of two rocks. The continental crust is mostly granite. The oceanic crust is basalt. Basalt is much denser than the granite. Because of this the less dense continents ride on the denser oceanic plates.

The Mantle

The Mantle is the largest layer of the Earth.

Convection Currents in the mantle

The Outer Core

• Composed of nickel and iron.

• Liquid State

The Inner Core

• Composed of Iron and Nickel

• Solid State