Unit 6 Part 1: The Structure of Earth

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Unit 6 Section 1: The Structure of Earth

Lesson Objectives

• Describe the basic chemical composition of the Earth's Compositional Layers

  • Crust

  • Mantle

  • Core

• Name and Describe the Earth's Functional layers

Word Cloud

What do you Know about the Earth's Structure?

Introduction-The Main layers of the Earth

• Earth can be divided up into three concentric layers based on their chemical composition

  • Concentric: two or more circles with a common center

• As you go deeper into the Earth, the temperature and the pressure increase

The Crust

• The Crust: Earth's Surface Layer

• The Thinnest layer

  • Ranges between 7 and 50 km thick

  • Only about 0.3% of the planet's volume

• Made of rocks that contain minerals rich in silicon and Oxygen

• Over time, shifts and move positions of rocks

• Divided into two parts

  • Continental Crust

  • Oceanic Crust

Continental Crust

• Continental Crust: Crust that makes up landmasses

  • About 40 km thick

• Made up of mostly light, low-density rock called granite

• Can be eroded over time and wind up in the ocean

Oceanic Crust

• Oceanic Crust: Crust that sits under the ocean

  • About 7 km thick on average

• Made of mostly a dense dark gray rock called Basalt

• Contains more iron and magnesium than the continental crust

Multiple Choice

How many layers of the Earth are there if when we look at chemical composition?

• 1

• 2

• 3

• 4

Drag and Drop

​

Placeholder

circles have a common center.​

Drag these tiles and drop them in the correct blank above

Concentric

Parallel

Intersecting

Coexisting

Drag and Drop

The crust is the ​

Placeholder

layer of the Earth, and makes up only ​

Placeholder

% of the planet's Volume.​

Drag these tiles and drop them in the correct blank above

thinnest

0.3

thickest

oldest

weakest

1

10

3

30

Categorize

Options (7)

Granite

basalt

more iron

more magnesium

thinner

is eroded

thicker

Organize these options into the right categories

Continental Crust

Oceanic Crust

Multiple Select

What are the two most abundant elements in the Earth's Crust

• Oxygen

• Silicon

• Nitrogen

• Iron

• Magnesium

The Mantle

• The Mantle is a thick layer of hot rock

  • Exists in a semi-solid state

• The Largest layer of the Earth, ~82% of its mass

  • 2900 Km Thick

How Do Geologists Learn about Earth's Interior?

• Scientists don't know much about the Mantle because it is hard to see and we can't drill into it

• Geologist: A scientist who specializes in studying the Earth, Rocks, and Minerals

  • ​Practice two methods to study the Earth

    • Looking at Rock Samples

    • Studying the behavior of seismic waves

Evidence from Rock Samples

• Geologists drill holes into the Earth to Collect Samples

  • Some as deep as 12.3 Kilometers ​

  • The plugs show the different layers of rocks

• Rocks are also blasted to the surface by volcanoes

• Scientists attempt to recreate the conditions inside the earth to test how rocks behave

  • Shoot the rocks with lasers​

Evidence from Seismic Waves

• Seismic Waves: an elastic wave in the Earth produced by an earthquake or other means

• Geologists record and study how seismic waves ​travel throughout the Earth

  • The speed and direction can indicate how waves move around different masses​

Properties of The Mantle

• Rock Samples show that the mantle is made up of mainly silicon and oxygen just like the crust

• The Mantle has larger amounts of Magnesium, iron, and calcium as well

  • These denser elements make the mantle more dense than the crust

The Core

• The Center of the Earth

  • Has a radius of about 3500 km

• Mainly made up of iron with smaller amounts of nickel

• Mainly studied through Seismic Waves

Multiple Choice

What sort of scientist studies the rocks and minerals that make up the Earth?

• astronomer
• botanist
• geologist
• zoologist

Multiple Choice

True or False: The Mantle is the thickest later of the Earth

• True

• False

Multiple Select

How have scientists learned about the Mantle of the Earth?

• Drilling a Hole to it

• Looking at Rock Samples

• Asking a Magic 8-Ball
• Studying Seismic waves

• Shining a light into the ground

Multiple Select

Which elements are more prominent in the mantle than in the crust

• Magnesium

• Iron

• Calcium

• Copper

• Nitrogen

The Structural Layers

• The three main layers of the Earth only focus on the chemical composition in the layers and not their properties

• When we look at the physical properties of the different parts of the Earth, we can divide it into 5 layers.

  • Physical properties studied:

    • temperature

    • pressure

    • strength

    • ability to flow

The Lithosphere

• Made up of the crust and the upper portion of the mantle

  • Also known as the "rock sphere"

• A shell of cool, rigid rock that ranges from 15 km to 300 km deep

  • Thicker below the continents than the oceans

• Broken up into pieces called tectonic plates

The Asthenosphere

• Lies under the lithosphere

• Made up of mantle rock that is soft and flows extremely slowly

  • Caries the pieces of the lithosphere on top of it

The Lower Mantle

• Sits between the aesthenosphere and outer core

• Hotter than the Aesthenosphere, but more solid and rigid

The Outer Core

• A shell of hot, liquid, metal

  • Mostly iron, but also some nickel

    • Creates The Earth's Magnetic Field that shields the Earth from solar wind particles

• Spins and flows as the Earth rotates

The Inner Core

• A solid sphere of hot metal

• Almost pure iron

• Temperature of 7000°C

  • High Pressure from all other layers keeps it solid.

Multiple Select

What does the iron in the outer core do for the Earth?

• Create the Earth's Magnetic Field

• Keep the Layers from collapsing in

• Protect the Earth from Solar Winds

• Attract the other layers together

Multiple Select

Which structural layer(s) of the Earth flow and move?

• Lithosphere

• Asthenosphere

• Lower Mantle

• Outer Core

• Inner Core

Multiple Choice

How are the five structural layers of the Earth categorized?

• By Chemical Properties

• By Size

• By Physical Properties

• By Age

Multiple Choice

Which layer of the Earth do we live on?

• Lithosphere

• Asthenosphere

• Lower Mantle

• Outer Core

• Inner Core

Labelling

Label the structural layers of the Earth

Drag labels to their correct position on the image

Lower Mantle

Lithosphere

Asthenosphere

Outer Core

Inner Core