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Earth Forces

Course Notes

Calderglen High School

By the end of this unit you should know about….

The structure of the Earth Continental Drift

The Earth’s plates and how they move Volcanoes and Earthquakes.

Calderglen High School Geography Department - 1 -

Test your vocabulary!

What does the word ‘molten’ mean?

Lesson 1: The Structure of the Earth

The shape of the Earth is a sphere. It is divided into different layers. Ever

wondered what our earth is made of? Think of it as an apple. An apple

constitutes the skin, the pulp and the core in the middle. Similarly, the earth is

made up of a series of layers, that is: the crust; the mantle; the inner core; and

the outer core. Each of these is described below.

The core is at the very centre of the Earth and is the hottest layer, reaching

temperatures of 5,500°C. The diagram shows that there is a molten outer core

and a solid inner core. The inner core is a solid ball, composed mainly of Iron.


Mantle

Skin

Inner & outer core

The crust floats on a layer of semi-molten rocks called the mantle. The mantle

is the thickest layer of the earth (approximately 3000km) and consists of semi-

molten rocks. Molten rock in the mantle is called magma.

The crust is the Earth’s hard and rocky surface and is the thinnest layer. The

crust of the Earth is not one solid piece like the skin of an apple. The Earth’s

crust is not a huge, solid piece of rock. Instead it is broken up into large pieces

which we call plates.

No-one has actually travelled to the centre of the Earth. What we do know

about the inside of the Earth comes from studying earthquakes and volcanoes,

just like we will do later in this unit.

So if we took a slice out of the Earth this is what it would look like (Figure 1.1):

Figure 1.1: Inside the Earth


Table 1.1 summarises the characteristics of the inside of the Earth.

Table 1.1: Characteristics of the layers of the Earth

Name of Layer Thickness (km) Temperature (˚C) StateCrust 10-60 10 Solid

Mantle 3000 375 Semi-moltenOuter Core 2000 5500 MoltenInner Core 1300 6000 Solid

Activity 1: The Structure of the Earth

(a) Your teacher will give you a diagram of the Earth’s Structure.

Using the word bank below, complete diagram 1 to show the

different layers of the Earth.

Once this diagram is completed, get scissors and glue and stick it

in your jotter.

Wordbank

b) Using Table 1.1 annotate your diagram with information about

thickness, temperature and state.

c) Colour your diagram in, using a different colour for each layer. Stick it

in your jotter!


Crust Inner Core

Mantle Outer Core

Direction of plate movement

Moving Plates

Figure 2.1: The Seven Main Plates

The crust

of the Earth is not one solid piece like the skin of an apple. The crust is made up

of pieces that fit together like a jigsaw. We call these plates. These plates

move slowly across the earth’s surface – much the same rate as your fingernails

grow (50mm each year). Where the plate edges meet is called a plate

boundary. These plates move slowly across the earth’s surface – much the

same rate as your fingernails grow (50mm each year). Where the plate edges

meet is called a plate boundary. It is at plate boundaries that most

earthquakes and volcanic eruptions take place, and where the highest

mountains occur.


The plates move because the mantle underneath the plates moves, as it is

heated by the enormous heat generated from the core of the Earth. This

movement is called a convection current. The movement of these currents is

similar to the movement of convection currents in a pot of boiling water.

Figure 2.2: Magma heats up and rises

Activity 2: Moving Plates

Instructions:

1. Using Figure 2.2. Identify and label the 8 main plates on to your diagram

2. Name each continent. You can use an atlas to help you.

3. Colour each plate in a different colour so you can easily identify each

one.


Lesson 2: Continental Drift

The plates on top of the mantle have been moving very slowly for many millions of

years. The movement of these plates is known as Continental Drift.

If we could travel back in time the shape of our continents would be very different

from today. Over 200 million years ago all the continents were joined together

forming a huge super-continent called Pangaea (Figure 3.1). Travelling forward in

time to 135 million years ago the continents started to drift apart (Figure 3.2). Today

the continents are in the positions shown in Figure 3.3.

The continents are still moving very slowly, 1-3 mm every year. In the future,

perhaps 100 million years from now, the continents will look very different from the

shapes we know today.

Figure 3.1: The continents 200 million years ago


Figure 3.2: The continents 135 million years ago

Figure 3.3: The continents today

The British Isles lies on top of one of the plates and it has been moving for many

millions of years (Figure 3.4).

Figure 3.4: The Movement of the British Isles

Evidence for Continental Drift


Although humans were not there at the time, there is evidence to support the

theory of continental drift.

If you look at the continents of South America and Africa on a map, they seem

to fir together, a bit like a jigsaw puzzle .

The same types of fossilised animals and plants have been found in South

America and Africa.

There are similar rock formations found in South America and Africa.

This evidence suggests that these continents were not always separate as they are

today, but that they were joined together at some point in the past.

Activity 3: Continental Drift Sorting Task


1. Collect a blank storyboard and a set of continental drift cards from your

teacher.

2. In your group you must sort these into the correct order to tell the story of

continental drift.

Activity 4: Continental Drift

1. Look at the map below which shows Pangaea. Name the continents

numbered 1, 2, 3, 4 and 5. (Hint: Use Figure 3.3 to help you)

2. Figure 3.4 shows the movement of the British Isles over the last 500 million

years. Describe the path that Britain has taken.

Lesson 3: Plate Tectonics


1

2 3

4 5

Asia

Europe

http://www.google.co.uk/url?sa=i&rct=j&q=group+work&source=images&cd=&cad=rja&uact=8&ved=&url=http://issuesincyberspace.blogspot.com/2011_02_06_archive.html&ei=-M9JVY8_gtlq4sCB6Ag&psig=AFQjCNFRzBiXB0JOBi9XIihhp0CugIl42w&ust=1430987128317559

Direction of plate movement

Plate Boundary Types

The point at which the Earth’s plates meet is called a plate boundary. Because the

Earth’s plates are moving many of the Earth’s and earthquakes and volcanic

eruptions take place at found at plate boundaries where the Earth’s crust is

weakest.

The Earth’s plates can move in three directions:

Some slide past each other (sliding plates),

Some move towards each other (colliding plates), and

Some move away from each other (parting plates).

Sliding Plates


As sliding plates move past each other

friction builds up. Just like if you rub the palms of your hands together!

Sliding plates occur when two plates move alongside each other. Sliding plates can

cause earthquakes. An earthquake is produced when plates stick as they are sliding

past each other. The pressure between the two plates builds up and then they jolt

apart. It is the jolting motion that produces earthquakes.

Colliding Plates

Colliding plates are two plates which move towards each other and then collide into

each other. During the collision of the two plates mountains are formed.

Earthquakes and volcanoes can also be produced.

Parting Plates

Parting plates are two plates which are moving away from each other. When the

plates move apart, hot molten rocks called magma wells up to fill the gap between

the plates. This hot magma then cools down and a new crust is formed.


As the plates collide the weaker plate is forced under the stronger plate!

Figure 4.4 shows the main plates of the Earth. The arrows show the plates that are

sliding, colliding or parting.

Figure 4.4: World Plates and their Movement

Activity 5: Plate Movements

Instructions:

1. Make a copy of Diagrams 4A, 4B and 4C. Draw arrows on the diagrams to

show the movements of the three types of plates.

Diagram 4A: Parting Plates Diagram 4B: Colliding Plates

Diagram 4C: Sliding Plates


2. Draw arrows to show the direction of the moving plates on your world map

plate tectonics diagram from Lesson 1 (in your jotter).

3. Put an X at the place where the plates are parting.

4. Put a Y at the place where the plates are colliding.

5. The arrows on Figure 4.4 show the direction in which each plate is moving.

Copy the sentences below and delete the words that are wrong.

a) The Eurasian plate is moving (towards/away from) the North American plate.

b) The Eurasian plate is moving (towards/away from) the Pacific plate.

c) The South American plate is moving (towards/away from) the Nazca plate.

6. Answer the following questions using Figure 4.4.

a. Name 3 plates with continents on them.

b. Name two plates without continents on them.

c. Name the plate on which Britain is located.

d. Which two plates divide New Zealand?


Lesson 4: Location of Earthquakes and Volcanoes

Earthquakes and volcanoes are found approximately in the same places. Figure 5.1

shows the location of earthquakes on the crust of the Earth.

Figure 5.1: Location of Earthquakes

The pattern is that the earthquakes are found along the edges or boundaries of the

plates. At the boundary of plates (the area where two plates meet) the plates are

either sliding, colliding or parting. It is these movements that cause earthquakes.

Figure 5.2 shows the location of the world’s volcanoes.

Most of the world’s volcanoes are found at the plate boundaries.

Figure 5.2: Location of Volcanoes


The pattern is that the volcanoes are found along the edges or boundaries of the

plates

Figure 5.3 shows the location of earthquakes and volcanoes along the plate

boundaries of the Earth. There is a clear pattern to be seen. Earthquakes and

volcanoes are usually found along the boundary of the world’s plates.

Figure 5.3: Location of Earthquakes, Volcanoes and World Plates


Activity 6: Location of Earthquakes and Volcanoes

Read these statements and choose 3 which are correct- copy these into your jotter :

• Earthquakes and volcanoes happen everywhere.

• Earthquakes and volcanoes often happen in the same places.

• Earthquakes and volcanoes happen in the ocean as well as on land.

• Earthquakes and volcanoes only happen in hot countries.

• Earthquakes and volcanoes happen mainly on large continents.

• Earthquakes and volcanoes occur along plate boundaries and fault lines.

Activity 7: Location of Earthquakes and Volcanoes

Instructions:

1. Draw Table 5.1 and use Diagram 5A to match up the numbered volcanoes to

the correct name for each. (You may wish to use an Atlas).

Table 5.1


Volcano Name Number

Mt. Kilimanjaro

Mt. Pelee

Mt. Fuji

Tristan da

Cunha

Mt. Etna

Krakatoa

Paricutin

Mt. St Helens

Mt. Vesuvius

Surtsey

Hawaii

Canary Islands

Diagram 5A

2. Study Figures 5.2 and 5.3 in this booklet. Where are most volcanoes found?

3. Draw Table 5.2 and use Diagram 5B to match up the numbered earthquakes

to the correct place name for each. (You may wish to use an Atlas).

Table 5.2

Diagram 5B


1

234

5

6

7

8

910

11

12

Place Name Number

San Francisco

Mexico City

Peru

Mindanao

Armenia

Turkey

Guatemala

Iran

China

Bucharest

Papua/New

Guinea

Indonesia

4. Study Figures 5.1 and 5.3 in this booklet. Are earthquakes found along the

boundary of the plates or in the middle of the plates? Give reasons for your

answer.


1

234

5 6 7 8

9

101112

How is a Volcano Formed?Millions of years ago, magma forced its way between two plate tectonic boundaries

The lava cooled and turned into rock. Many years later magma forced its

way up again

The process repeated over and over again. The cooled lava formed layers

of rock

In between, the volcano spewed out ash and steam. The ash settled on the

volcano and cemented into rock

Over millions of years, the layers built up to form a volcano

Lesson 5: Volcanoes


Volcanoes are formed by molten material rock from the mantle. It is called magma

and is forced through an opening in the Earth’s crust called a vent.

Figure 6.1: Features of a Volcano

The Main Features of a Volcano DescriptionOriginal crust Rocks which existed before the volcanoMagma chamber Large underground pool of magma below the

volcanoPipe or vent Central tube which magma travels through, this is

how lava reaches the surfaceCrater The hole at the top of a volcano where lava and

ash escape.Gas & Dust cloud Fine fragments of rock, minerals and volcanic

glass created during eruptions and thrown into the air above the crater

Lava bombs Large pieces of rock thrown out of the volcanoPyroclastic flow A cloud of very hot ash which rolls down the side

of a volcanoLayers of ash & lava Build up to create the shape of a volcanoLava flow Hot molten rocks flow down the side of the

volcano


We can describe volcanoes depending on when they last erupted.

Active volcanoes: recently erupted and are likely to erupt again.

Dormant (sleeping) volcanoes: show no sign of erupting, but could erupt again in

the future.

Extinct volcanoes: have shown no signs of erupting over the last 10,000 years and

are highly unlikely to erupt again. Arthur’s Seat in Edinburgh is a good

example, this volcano was active about 340 million years ago.

Activity 8: Volcanoes

1. Make a sketch of Diagram 6A. Using the information from Figure 6.1, label

your sketch with the following terms:

Crater Lava Bombs Magma Chamber

Lava Flow Main Vent Gas & Dust Cloud

Layers of Ash &Lava Pyroclastic Flow Original Crust

Diagram 6A

2) Using your diagram of ‘An Active Volcano’ and the information above, describe

what happens when a volcano erupts by putting the following stages in order.

A volcanic eruption


gas, steam, ash and lava bombs are blown out through the crater

lava flows down the side of the volcano

magma builds up under great pressure in the magma chamber

magma erupts through the vent

3.What do you think is meant by:

a. An active volcano?

b. A dormant volcano?

c. An extinct volcano?

Lesson 6,7 and 8: Volcanoes Case Study- Eyjafjallajokull, Iceland Eyjafjallajokull, (pronounced ay-yah-FYAH-plah-yer-kuh-duhl).


In March 2010, magma broke through the crust beneath Eyjafjallajokull glacier. This

was the start of two months of dramatic and powerful eruptions that would have an

impact on people across the globe.

It erupted twice in 2010—on 20 March and in April/May. The March event forced a

brief evacuation of around 500 local people, but the 14 April eruption was ten to

twenty times more powerful and caused substantial disruption to air traffic

across Europe. It caused the cancellation of thousands of flights across Europe and

to Iceland.

Timeline of events

20 th March 2010 – Small eruptions start from the volcano.

12 th April 2010 – Hundreds of small earthquakes happen; a sign that a bigger

eruption is on the way.

13 th April 2010 – A large eruption happens directly underneath a large amount of

ice causing it to melt. The water mixes with lava and creates a huge ash cloud.

14 th April 2010 – The ash cloud from the volcano reaches up 8km into the sky.

15 th April 2010 – Ash has blown all over Europe, causing countries to close their air

space and stop planes.

17th April 2010 – The eruption continued but less explosively meaning that the

amount of ash being erupted was getting smaller, however countries still had to

close airspace as the ash already in the air spread out over Europe.

19th April 2010 – The first countries reopened their airspace; including Germany,

Poland and Switzerland.

20 th April 2010 – All airspace was reopened and it was safe for planes to fly over

Europe again.

Figure 7.1: Airspace affected by the eruption


Green: Iceland

Orange: Countries that stopped some flights.

Red: Countries that stopped all flights

Lesson 9: Earthquakes


Figure 7.2: Ash Cloud on 16th of April 2010

An earthquake is a sudden movement of the rocks in the Earth’s crust. The quick

movement of the rocks sends shock waves through the crust (like when you throw a

stone into a pond) and when they reach the surface, the ground shakes resulting in

an earthquake.

Earthquakes are very common – there is one somewhere in the world every 2

minutes.

Figure 9.1: Shock Waves on A Pond

Figure 9.2: Shock Waves on the Ground


Earthquakes start below the Earth’s surface at a point called the focus. The shock

waves spread out from this point. The epicentre is the point on the Earth’s surface

directly above the focus. The epicentre is the place where the earthquake is felt

most and causes the most damage.

Earthquakes are measured by a special instrument called a Seismograph (Figure

7.3). A Seismograph is an extremely sensitive instrument that records tremors of the

Earth’s surface.

Figure 9.3: A Seismograph

The strength of an earthquake can be shown on a scale known as the Richter Scale.

The Richter scale begins at 0 and continues to 12. The higher the number the

greater the strength of the earthquake (Figure 9.4).


Figure 7.4: The Richter Scale

Each point on the Richter Scale is 10 times greater than the one before. On this

scale, scale 6 would be 10 times more powerful than scale 5, and scale 7 would be

10 times more powerful than scale 6.

Activity 9: Earthquakes


Write out the paragraph below and use the words to fill in the blanks.

earthquake

stick

crust

plate

fault

plates

jolt

faults

pressure

How earthquakes are caused:

The Earth’s c____ contains many cracks. These cracks are called f_____. The main

f____ lines are found along the p____ boundaries. When two p_____ slide past each

other the movement is so slow that it is hardly noticed. Sometimes, the plates s____

together and p_______ builds up. Eventually the plates free themselves with a j___

which shakes the ground violently. This violent shaking is called an e_________.

Activity 10: Effects of an Earthquake

Copy Diagram 9A onto a separate sheet of paper. Create a picture board to show

some of the effects of an earthquake.

Diagram 9A

Effects of an Earthquake

Buildings collapse People injured and killed Water pipes burst

Tsunamis (tidal waves) Fires break out Roads damaged

Activity 11

Table 9B below shows the number of deaths from various earthquakes.


Draw a bar graph showing these deaths.

(Hint: It should look like the one in Diagram 9C)

Table 7.1: Deaths From Earthquakes

Date Location Deaths

1906 San Francisco, USA 1000

1985 Mexico City, Mexico 10000

1976 Guatemala 23000

1986 El Salvador 1500

1980 Naples, Italy 4800

1977 Romania 1500

1980 Algeria 4500

1982 North Yemen 23000

1968 Khurusan, Iran 12000

1978 Tabas, Iran 25000

1976 Philippines 8000

1976 Turkey 4000

Diagram 9C

1906

1976

1980

1980

1968

1976

040008000

1200016000200002400028000

Deaths From Earthquakes

(Year)

(Dea

ths)

Extension Task

1. Use an Atlas to locate these earthquakes.


Lesson 10 and 11: Case Study: Nepal Earthquake

On Saturday April 25th, 2015, a huge earthquake struck the Himalayan nation of

Nepal. The quake flattened large parts of the capital Kathmandu and caused

widespread devastation. Figure 7.2 shows the location of Nepal.

Figure 7.2: Location of Nepal

The Indo-Australian Plate pushes against the Eurasian plate and has caused the

formation of Himalayan Mountains. These mountains are still growing by around

1cm a year!

The huge pressure that builds up at this plate boundary was suddenly released as

the plates jerked apart, causing the earthquake. The earthquake measured 7.8 on

the Richter Scale.

Impact of the earthquake

The earthquake is Nepal's worst natural disaster in 80 years.


More than 8,000 people are known to have died in Nepal.

13,932 have been injured across the country.

The United Nations estimates that eight million people have been affected.

UNICEF estimates that 1.7 million children live in the worst-hit areas.

The impacts of the earthquake can be classified into social, economic and

environmental impacts.

Social Impacts are impacts on people. For example, people’s houses may be

destroyed.

Economics Impacts are impacts on the wealth of an area. For example, it may be

very expensive to rebuild destroyed buildings.

Environmental Impacts are impacts on the landscape. For example, landslides or

flooding.

Activity 12: Nepal Earthquake

Your teacher will show you some images from the Nepalese earthquake. In your

jotter write down at least 10 effects of the earthquake.


Once you have done this, classify each effect into social, economic or

environmental effects.

Activity 13: Aid Effort

Working in a group, decide what help would be needed after the Earthquake.

Draw a mind map in your jotter to show your thoughts.

Activity 14: Earthquake Survival Kit

The Nepalese Prime Minister has told all locals to put together an earthquake

emergency kit that would be useful in the event of another earthquake.

What do you think would be essential to have in the event of an earthquake?

Draw a diagram of a rucksack in your jotter and think of as many items as possible

that you might need to survive.

Once you have finished, swap with your neighbour and compare answers. Add in

any items that you have missed out.

Activity 15: Earthquake Survival Flyer

Create a flyer that will be given to people living in earthquake hazard zones.

You need to give them 3 top tips for surviving an earthquake.

Try to convince people to do these things, so justify why it is important.

Include diagrams!

Calderglen High School – Geography Department Evaluation Sheet

Name Topic Mark/LevelEarth Forces Second Year


1. Circle the number, which reflects your feelings about the course you have just completed.

Very enjoyable 1 2 3 4 5 Not enjoyableVery easy 1 2 3 4 5 Very difficultVaried work 1 2 3 4 5 RepetitiveLots of Video/internet 1 2 3 4 5 Few videos/ internetH/W interesting 1 2 3 4 5 H/W boringQuality workguides 1 2 3 4 5 Poor qualityHelp available 1 2 3 4 5 No help availableLots of encouragement

1 2 3 4 5 Little encouragement

2. What part of the course did you particularly like?

3. What part of the course did you particularly dislike?

4. Suggest 3 things that you will do to help your learning in the next topic.

5. Suggest any improvements that can be made to the unit to make it more interesting/easier to learn.


earth forces - calderglen high school … · web viewis at the very centre of the earth and is...

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