layers of the earth grade 7

Layers of the Earth

Science

INSTRUCTIONS

• Go to a new page, write down topic, essential question, date from the white board.

• Copy all underlined text.

Learning Objectives:

1. Name and describe the Earth's layers and describe the relative densities of the rocks that are contained in each layer. 

Two main ways scientists understand the inside of Earth:

- Rock Samples
- Drilled up from 7 miles deep
- Volcanos carry rock from 60 miles deep

- Seismic Waves
Scientists use earthquake data to understand what makes up the inside of the Earth

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How do we know?

Multiple Choice

How do scientists know what's inside the Earth?

• Rock Samples and Earthquakes

• We've sent equipment to the center of the Earth

• A massive x-ray machine

• Time travel back to watch the Earth form

Explore

​Work with your group members to complete task

Research: Allow groups to research their assigned layer using textbooks or online resources to gather information about its composition, characteristics, and significance.
Student will create a poster that includes:-
1- a diagram of the earth's layers highlighting their specific layer
2- Key characteristics of their layer ( temperature , composition, depth, an interesting fact)
Site your Sources
Duration 20 mins

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There are 4 main layers of the Earth. Each of these has different compositions, thicknesses, and properties.

The 4 main layers are:

- Crust
- Mantle
- Outer Core
- Inner Core

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The Layers

Pressure

The deeper inside Earth, the greater the mass of the rock that is pressing down from above. This creates pressure. The deeper down inside the Earth, the greater the pressure is.

Temperature

The mass of rock that presses down and causes this pressure also affects the temperature inside the Earth. The temperature inside the Earth increases as depth increases. The intense pressures squeeze rocks together and releases energy from radioactive substances.

The Crust

• Outermost and thinnest layer of Earth

• 2 types of crust - Continental and Oceanic

• Composed mostly of oxygen, silicon, and aluminum

The Crust

• Usually between 3-25 miles thick (5-40 km)

• Can be as thick as 80 km under mountains and very thin beneath the ocean

Oceanic Crust

• The part of the crust that lies beneath the ocean is called oceanic crust

• It is made of basalt, which typically forms from cooling lava

Continental Crust

• Continental crust is what forms all of Earths' land masses

• Depending on the location, the composition varies greatly

• Overall, it is mostly types of granite

- Directly below the Crust.

- Nearly 3,000 km thick

- Temp goes up the deeper you go - range from: 1,600°C to 2,900°C

- Material is still solid but very bendable - think tinfoil

- Where convection currents happen

Mantle

The Mantle

Divided into 3 main layers based on physical characteristics.

Lithosphere

• Made up of the crust and upper mantle

• Averages about 100 km thick

Asthenosphere

• A soft layer beneath the lithosphere

• Material is hotter and under higher pressure

• This layer can bend and "flow" like a melted plastic, but is still solid

Mesosphere

• This layer is hotter but more stiff than the asthenosphere

• This is due to the increasingly high pressure

• Includes the lowest part of the mantle and part of Earth's core

• Molten metal (nickel and iron) surrounding the inner core.

• 2,200 km thick

• 4,500°C - 5,500°C

Outer Core

• Solid metal (nickel and iron) under extreme pressure

• 1,220 km radius

• 5,000°C - 5,500°C

​​Inner Core

The Core and Earth's Magnetic Field

Scientists believe that movements inside the liquid outer core create the magnetic field around the Earth

Reorder

Put the layers of the Earth in order from outside to inside.

• Crust

• Mantle

• Outer Core

• Inner Core

1

2

3

4

• 1
• 2
• 3
• 4

Let's Explore
Go to your stations
read instructions on the tab/ board

Multiple Choice

Which of these is NOT a layer of the Earth?

• Crust

• Mantle

• Core

• Skin

Dropdown

The Earth's crust is the

Select answer

of all the layers.

Hotspot

Where in this picture would we find Continental Crust?

Select all that are correct.

Multiple Choice

Which layer has convection currents?

• Continental Crust

• Oceanic Crust

• Mantle

• Moon

Labelling

Label the layers.

Drag labels to their correct position on the image

Mantle

Continental Crust

Oceanic Crust

Open Ended

The Inner core is solid and the Outer core is liquid, even though they are about the same temperature. Why is the Inner core solid?

Multiple Select

Select the THREE characteristics that describe the oceanic crust.

• mostly granite

• thinner form of crust

• older form of crust

• made mostly of basalt

• 5–10 km thick

Multiple Select

Select the THREE characteristics that describe the asthenosphere.

• contains the upper mantle only

• made of less rigid rock, like silly putty

• closer to Earth’s surface

• made of solid rock

• contains the crust and upper mantle

Multiple Select

Select the THREE characteristics that describe the mantle.

• thickest of Earth’s layers

• average temperature of 3000°F

• rocks rise and sink through convection

• thinnest of Earth’s layers

• made of rock rich in nickel and lead

Multiple Select

Select the THREE characteristics that describe the inner core.

• made of liquid nickel and iron

• spins faster than Earth rotates

• 1,250 km thick

• made of solid nickel and iron

• 2,300 km thick

Multiple Choice

Your classmates are having a disagreement on what creates Earth's magnetic field. Each student saw the diagram above and stated that a different part is responsible for the magnetic field. Melena: Part 1, the crust. Jordan: Part 2, the mantle. Corinne: Part 3, the outer core. Michael: Part 4, the inner core. Which student is correct?

• Melena

• Jordan

• Corinne

• Michael

Multiple Choice

Which evidence supports the answer best?

• The solid core spins as Earth rotates.

• Convection in the mantle creates a magnetic field.

• Magma in the outer core moves to create a magnetic field.

• Metals in the crust rotate with Earth to make a magnetic field.

Multiple Choice

A team of scientists sent a deep ocean probe to study the ocean floor. Explain how the oceanic crust studied by the submarine is different from the crust found on a continent.

• The oceanic crust is made mostly of granite. It is also thicker, older, and not as deep as the continental crust.

• The oceanic crust is made mostly of basalt. It is also denser, thinner, younger, and deeper than the continental crust.

• The oceanic crust is below the mantle and is made mostly of magma. It is not very thick.

Multiple Choice

Your science teacher heats a beaker of water on a burner. She then adds rice to the heating water. The rice spins in the water as shown below. Which layer of Earth’s crust does this model the best? Explain why.

• The demonstration models the crustal layer best. It shows that volcanoes can exist under water because of the molten rock circulating in the currents of the Earth.

• The demonstration models the core layer best. The rice spinning in the heated water represents the magnetic field circulating in the convection currents of the outer core.

• The demonstration models the mantle layer best. The rice spinning in the heated water represents the molten rock circulating in the convection currents of the mantle.

Multiple Choice

Scientists know a lot about Earth’s layers, but we have never dug below the crust. Explain how seismic waves help us understand Earth’s layers.

• Earthquakes and rock movement create seismic waves. These waves travel through Earth’s layers but cannot pass through certain materials. This helps us understand which layers are solid and which are liquid.

• Avalanches cause erosion, deposition, and seismic waves. The waves cannot travel through the solid crust unless they are really strong. This helps us understand that some layers are rocky and other layers are watery.

• Seismic waves are created by wind and water energy. They can only travel through the oceanic crust. This helps us understand which layers are land and which are water.