Layers of Earth

Layers of Earth

Journey into the Center

First, lets review density!

Multiple Choice

If an object is less dense it will.....

• sink

• float

Multiple Choice

If an object is more dense it will.....

• sink

• float

Multiple Choice

Based on what we know about density, would we find more dense layers in the center of the Earth or less dense layers in the center of the Earth?

• More dense in the center

• Less dense in the center

Earth's Composition

-The Earth is divided into three layers- the crust, the mantle, and the core.

-These layers are made up of different compounds

-Remember a compound is a substance composed of two or more elements.

-The less dense compounds make up the crust and the mantle.

-The more dense compounds make up the core.

Lets start with the Crust

The Crust

The crust is the outermost layer and the thinnest

 There are two types of crust: continental and oceanic.

Both crusts are made mainly of the elements oxygen, silicon, aluminum. (Rocks and minerals)

Multiple Select

What are the two types of crust?

• Oceanic

• Continental

• Thick

• Tectonic Plate

Next, the Mantle

The Mantle

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

The mantle is much thicker than the crust and contains most of the Earth’s mass (84%)

The mantle has more magnesium and less aluminum and silicon than the crust, making it much more dense

Upper Mantle

The Lithosphere: Made up of two parts- the crust and the rigid upper part of the mantle. This is where tectonic plates are found

The Asthenosphere: Plastic / Silly putty like part of the mantle that the lithosphere sits on

Convection currents in the mantle cause movement. Movement of the asthenosphere moves tectonic plates.

Multiple Choice

What is denser? The lithosphere or the asthenosphere?

• Lithosphere

• Asthenosphere

Open Ended

What causes the tectonic plates to move?

Moving on to the Core

The Core

The Outer Core: The liquid layer of the Earth’s core that lies beneath the mantle and surrounds the inner core.

The Inner Core: The solid, dense center of our planet that extends from the bottom of the outer core to the center of the Earth. (3,964 miles beneath the surface)

Open Ended

Put the layers of the Earth in order from the outermost layer to the innermost (including the upper mantle)

Multiple Choice

True or False. The mantle is hotter than the crust.

• True

• False

Multiple Choice

True or False. The Earth's crust is thicker than the inner layers.

• True

• False

Multiple Choice

What layer of the mantle is flexible like plastic?

• lithosphere

• asthenosphere

• lower mantle

Multiple Choice

What causes the asthenosphere to move?

• Convection currents

• Outer Core

• Inner Core