Earth Structures

Unit Review:
Earth‘s
Structure

October 3rd, 2024

Review

• In this unit, you learned about:

o the components of Earth,

including its atmosphere and
lithosphere

o the composition and layers of

the atmosphere

o the weather
o the movement of Earth‘s

tectonic plates contributes to
the formation of earthquakes
and volcanoes

o the rock cycle

Match

Match the description with the correct vocabulary term.

• Earth‘s innermost layer

• rigid outer layer of Earth, consisting of the crust and the uppermost part of the mantle

• an extremely significant feature of the stratosphere, it is a layer made up of ozone molecules that absorb most of the sun‘s ultraviolet (UV) radiation

• the vertical distance between a point and sea level

inner core

lithosphere

ozone layer

elevation

• inner core

• lithosphere

• ozone layer

• elevation

Match

Match the description with the correct vocabulary term.

• 
  winds that blow consistently from a particular direction over an area

• when tectonic plates move toward each other

• when one tectonic plate moves beneath another

prevailing winds

convergence

subduction

• prevailing winds

• convergence

• subduction

Match

Match the description with the correct vocabulary term.

• particles derived from the weathering and breakdown of rocks, minerals, and organic materials

• the geological process of raising Earth‘s crust or rock layers to higher elevations

• a volcano that is formed by a stationary magma source beneath Earth‘s crust, creating volcanic activity at the surface

sediment

uplift

hotspot volcano

• sediment

• uplift

• hotspot volcano

Earth‘s Layers
Review

• Earth‘s lithosphere is made

up of the crust and the
uppermost part of the
mantle.

• The crust and the mantle

are two of Earth‘s layers.

• The outer core and the

inner core are the other two
layers.

Earth‘s Layers Review

• The crust is relatively thin as

compared to other layers. Mountains,
valleys, landscapes, and living
organisms are found on Earth‘s crust.

• The mantle is partially molten, and its

movement and heat flow plays a
crucial role in shaping Earth‘s
surface. The semifluid layer called
asthenosphere is present in the
upper mantle region.

Earth‘s Layers Review

• The outer core is mostly liquid in

nature. It plays an important role in
generating Earth‘s magnetic field.

• The inner core is a solid ball due to

extremely high pressure conditions
and high-density composition.

• Scientists used information obtained

through S- and P-wave activity to
distinguish Earth‘s layers.

Reorder

Sort the layers of Earth from the innermost to the outermost.

• inner core

• outer core

• mantle

• crust

1

2

3

4

• 1
• 2
• 3
• 4

Earth‘s Atmosphere
and Weather Review

• The atmosphere is primarily

composed of gases, with nitrogen
and oxygen being the most
abundant.

• Other components include argon,

carbon dioxide, and trace gases.

Earth‘s Atmosphere and Weather Review

• The atmosphere is divided into unique

layers, including:

o the troposphere, where weather

occurs

o the stratosphere, which is home to

the protective ozone layer

o the mesosphere, where shooting

stars can be seen

o the thermosphere, where the

aurora borealis occurs

o the exosphere, which is where

satellites orbit Earth

Earth‘s
Atmosphere and
Weather Review

• The atmosphere has

important functions,
including:

o protecting life on Earth

by absorbing harmful
solar radiation

o regulating

temperatures through
greenhouse gases

o facilitating weather

patterns

Earth‘s Atmosphere
and Weather Review

• Human activities greatly impact the

atmosphere.

o The use of chlorofluorocarbons

(CFCs) leads to the thinning of
the protective ozone layer.

o Activities, such as the burning of

fossil fuels, contribute to the
release of greenhouse gases,
altering the composition of the
atmosphere. This has led to the
global warming crisis.

Multiple Choice

Which layer of Earth‘s atmosphere is closest to the planet’s surface and where weather occurs?

• troposphere

• stratosphere

• mesosphere

• thermosphere

Weather and Climate

• Earth‘s atmosphere plays an important

role in shaping weather patterns across
the globe.

• The interactions within this

atmospheric system influence the
diverse and changing conditions you
experience as weather.

• Weather encompasses short-term

atmospheric conditions.

• In contrast, climate describes the long-

term weather patterns in a particular
region over 30 years or more.

Multiple Choice

Which of the following phrases best defines climate?

• daily variations in atmospheric conditions

• long-term weather patterns in a specific region over 30 years or more

• short-term weather patterns over a few weeks

• changes in atmospheric pressure within a given month

Wind Patterns

• Wind patterns, influenced by

Earth‘s rotation and
temperature variations, create
dynamic air movements across
the planet.

• These atmospheric flows play a

crucial role in shaping climate
and weather systems.

Polar Easterlies

• Polar easterlies are dry, cold

prevailing winds that flow from
the east.

• These prevailing winds originate

from the north and south poles,
and drive air toward the
equator.

Prevailing Westerlies

• Prevailing westerlies are winds

of the mid-latitudes that blow
from the west.

• The prevailing westerlies are

strongest in the winter.

Trade Winds

• Trade winds are prevailing

winds that come from the east
near the equator.

• Trade winds have been

influential throughout history
due to their predictability by
facilitating exploration and
trade.

• Most tropical storms start as

trade winds.

Multiple Choice

Which term describes the prevailing winds that come from the east near the equator?

• trade winds

• polar winds

• prevailing westerlies

• polar easterlies

The Lithosphere and Plate Tectonics

• The lithosphere is the outer layer of

Earth, encompassing both the crust
and the uppermost part of the
mantle.

• It plays a crucial role in Earth‘s

dynamic processes, participating in
phenomena such as plate tectonics,
earthquakes, and volcanic activity.

• The lithosphere‘s composition and

structure contribute to the changing
nature of Earth‘s surface.

Earthquakes

• Earthquakes happen when there is a

sudden burst of energy in the ground.

• This usually occurs along lines where

pieces of Earth‘s crust are moving
around.

• When the pressure builds up in these

areas, it gets released, making the
ground shake.

• This released pressure is what one feels

during an earthquake.

Earthquakes

• Seismic faults are cracks or

fractures in Earth‘s crust where
rocks on either side have moved due
to tectonic forces, often causing
earthquakes.

• These faults contribute to seismic

activity.

Earthquake Faults

Normal faults

Reverse faults

Normal faults occur when rocks on one side of the fault move downward relative to the other side. These faults are often associated with divergent plate boundaries, where tectonic plates move away from each other.

Reverse faults form when rocks on one side of the fault move upward relative to the other side. These faults commonly occur at convergent plate boundaries, where tectonic plates move toward each other, leading to the uplift of rock layers.

Earthquake Faults

Strike-slip Faults

Blind Thrust Fault

Strike-slip faults result from horizontal
movements where rocks on either side of the fault slide past each other. The motion is primarily horizontal and is associated with transform plate boundaries, where tectonic plates slide horizontally past each other.

A blind thrust fault is a type of fault in which rocks on one side of the fault move upward or downward relative to the rocks on the other side. However, a blind thrust fault does not extend all the way up to Earth's surface.

Multiple Choice

What is the primary cause of earthquakes?

• volcanic eruptions

• meteorite impacts

• movement along lines in Earth‘s crust

• changes in atmospheric pressure

Volcanoes

Types of Volcanoes

Extinct Volcano

Hotspot Volcano

An extinct volcano is one that is no longer active. It has not erupted for thousands of years and shows no signs of future eruption.

A hotspot volcano is one that is formed by a stationary magma source beneath Earth‘s crust. This stationary source creates volcanic activity at
the surface.

Types of Volcanoes

Rift Volcano

Subduction Volcano

A rift volcano is one that is formed along a tectonic plate boundary where Earth‘s crust is pulling apart. This allows magma to rise and create volcanic activity.

A subduction volcano is one that forms at convergent tectonic plate boundaries, where one plate sinks beneath another. This leads to magma ascent and volcanic activity.

Multiple Choice

Which term best describes a volcano that forms at convergent tectonic plate boundaries?

• subduction volcano

• hotspot volcano

• rift volcano

• extinct volcano

The Rock Cycle Review

• The dynamic geological process

known as the rock cycle is the
process during which rocks are
formed, change, wear down, and are
formed again over long periods of
time.

• These phases of development,

change, and breakdown show how
Earth‘s surface is always changing.

Weathering and
Erosion

• On the surface of Earth, rocks break into

smaller pieces because of physical,
chemical, or biological processes.

• Rocks wear away due to:

o chemical reactions with acids or

other substances

o the actions of plants or animals.

• Worn-down rock particles are then

carried by the wind, water, or ice to
different locations.

Sedimentation
and Deposition

• Sediment is particles derived from the

weathering and breakdown of rocks,
minerals, and organic materials.

• Sediment is often deposited by water,

wind, or ice.

• Sediment layers are created as the

transported particles settle and build up
in new places.

• These layers have the potential for

combining and solidifying over time to
form sedimentary rocks.

Heat and
Pressure

• The temperature and pressure of

buried rocks rise with depth.

• Metamorphic rocks can arise as a

result of several circumstances.

• These circumstances include

intense heat, pressure, or chemical
processes that alter the mineral
makeup and texture of rocks.

Melting

• Magma can form when rocks in

Earth‘s mantle are heated to high
temperatures.

• When this molten material cools, it

has the potential to solidify and form
igneous rocks.

Types of Rocks

Igneous Rocks

Sedimentary Rocks

Metamorphic Rocks

Igneous rocks originate from molten materials beneath or on Earth‘s surface. Their formation involves the cooling and solidification of these molten materials.

Sedimentary rocks are formed through complex processes involving the accumulation of particles. These rocks provide valuable insights into Earth‘s history, preserving the record of past environments and conditions.

Metamorphic rocks are formed by changing preexisting rocks through the use of heat, pressure, or chemically active fluids. Examples include marble, which is made from limestone, and slate, which is made from shale.

Multiple Choice

In the rock cycle, which process leads to the formation of magma?

• weathering

• erosion

• melting

• deposition

Open Ended

Explain the difference between an extinct volcano and an active volcano.

Open Ended

Differentiate between weather and climate.

Summary

Today, you completed a review of the

concepts covered in Unit 2: Earth‘s
Structure.

In an upcoming lesson, you will

complete a test on this unit.

o If you have any questions

about the material you
studied, contact your teacher
before you attempt the test.

o Good luck on your test!