An earthquake is one of the worst natural disasters on our earth. We think that the

ground we stand on is very stable, but it isn’t. It moves quite a lot. In the last few

decades scientists have been able to find out why earthquakes happen.

Earthquakes happen when there is a sudden vibration in the earth’s crust. It’s like a

large lorry that travels down your street. When it passes by, you feel your house

shake.

Earthquakes can be caused by a lot of things :

+ Volcanoes that suddenly erupt

+ Meteorites that hit the earth

+ Undergrounds explosions

+ Buildings that fall apart

But most earthquakes happen because the earth’s plates move.

In the middle of the 20th century scientists found out that continents do not always

stay in the same place. They have been moving on plates for millions of years. The

earth’s surface is made up of many such plates. Where two plates meet magma

comes out of the inner part of the earth . These areas are called faults—breaks in the

earth’s crust.

HOW PLATES MOVE

When two plates move away from each other lava or

magma comes out of the earth. Most of this happens at the

bottom of oceans, where the earth’s crust is very thin. Lava

cools down when it reaches the water and underwater

mountains are formed.

When plates push towards each other—one of

them slides under the other. Rocks are pushed

up and new mountains are formed.

Some plates slide past each other— for example, one

moves north and the other moves south . When these

plates move along faults a lot of energy is released and

the biggest earthquakes happen.

Earthquakes

cause = the reason for some-

thing

crust = the top part of the

earth

decade = ten years

disaster = when something

very dangerous happens and a

lot of people die

erupt = to break out or ex-

plode

fault = where two plates meet

lorry = a car that carries lots

of goods

magma = rock in the inner

part of the earth that is liquid

plate = the earth’s crust

broke up into many plates and

the continents move on these

plates

reach = get to

release =let go

slide =move, go down

stable = it doesn’t move

sudden =unexpected, quick

surface =the top layer

towards each other =here:

two objects move to each other

1

We only hear about earthquakes once in a while , but they really happen every

day. There are more than 3 million earthquakes every year—about 8,000 every day

or one every 11 seconds.

But most of them are very weak or they happen in places where nobody lives. Some

of them take place on the sea floor.

WHERE DO EARTHQUAKES HAPPEN ?

Earthquakes occur all over the world but there are places where they happen more

often. Big earthquakes can be found where plates meet.

80% of the world’s earthquakes happen around the Pacific Ocean—near the east

coast of Asia and the west coast of America. Japan has over 2,000 earthquakes every

year and California and South America are also very active earthquake zones. The

edge of the Pacific Ocean is also called the “Ring of Fire” because there are also

many active volcanoes in this region.

Earthquakes

edge =border ,outer part of

occur = happen

once in a while = sometimes

take place = happen

volcano = a mountain that

often explodes and rock, gas

and lava come out of it

weak = not very strong

zone = places, areas

2

The Ring of Fire

around the Pacific

Ocean

EARTHQUAKE WAVES

When there is a sudden movement in the earth’s crust, energy moves in the form of

waves . It’s like dropping something into water.

Body waves move through the inner part of the earth and surface waves travel over

the earth’s surface.

Body waves can travel very fast—up to 8 km a second. They travel through rock ,

water and gas . When they reach other places on the earth’s surface they can be reg-

istered there. They are usually the first waves to get to the surface.

Surface waves cause the most damage, but they move very slowly. These waves

come at the end of an earthquake.

MAN-MADE QUAKES

Sometimes people can make earthquakes happen. They can fill man-made lakes

with water after building a dam—or they test atomic bombs underground. Some of

these tests can help scientists find out how quakes happen.

HOW EARTHQUAKES ARE MEASURED

With a machine called a seismograph scientists can tell where an earthquake hap-

pened and how strong it was.

The place in the earth where the move-

ment takes place is called the focus or

hypocentre. From here, waves start to

spread out in all directions. This focus

can be very near to the surface or it can

be hundreds of km below it. The area on

the surface exactly above the focus is

called the epicentre. This is the place

where the waves hit first and where the

most damage is done.

Whenever an earthquake hits us you hear how powerful it is. The Richter Scale is

used to rate the magnitude of earthquakes. Small quakes have a rating of under 4.

You won’t see a lot of damage here. Medium-sized earthquakes reach between 5

and 7 on the scale, and the really big ones are above 7. The largest earthquake that

has ever been registered was at 9.5 on the Richter scale.

There are more than 100 seismograph stations all over the world. When the earth

shakes seismologists compare the information they get and then they can tell where

the earthquake really happened.

Earthquakes

compare = to exchange the

information you have with

others

damage =destruction

direction =way

magnitude = tells us how

strong an earthquake is

man-made = something

caused or made by a person

medium-sized = not so big

and not so small

movement =when something

moves

rate =rank, measure how

strong something is

reach =go from .... to

registered = recorded

spread out = to move

3

Focus

Epicentre

EFFECTS OF EARTHQUAKES

Earthquakes make the ground move. Buildings shake and many of them collapse.

Landslides also happen when rocks get loose.

Another danger is fire. In 1906 San Francisco was hit by a big earthquake and many

houses burned down because they were made of wood.

When an earthquake occurs on the sea floor, big waves - called tsunamis—hit the

coast. They often come without any warning and they kill many people and destroy

buildings and streets near the coast.

Earthquakes also can lead to diseases, especially in developing countries. When

water supplies are destroyed people don’t have safe water to drink. Sometimes

earthquakes also hit hospitals where injured people are treated.

DEALING WITH EARTHQUAKES

We understand earthquakes a lot better today than we did 50 years ago, but we still

can’t do very much about them. They are so powerful, that we cannot control them.

Scientists can tell us in which regions earthquakes will probably happen, but they

can’t tell us exactly where.

So what can we do about earthquakes ? We can make our houses we live in and

buildings we work in safer. Today architects use materials that won’t collapse when

an earthquake hits—like steel and concrete.

Earthquakes

collapse = to fall down

concrete = a very hard mate-

rial made of cement

developing countries = the

poorest countries in the world

especially =above all

injured = hurt

landslide = rocks move

down mountains and destroy

houses or block roads

lead to =to be the reason for

loose =movable, to come

free, not fixed

occur = happen

safe water = clean water

supplies =reserves

treat =care for, take care of

4

The San Francisco earthquake of 1906 destroyed

most parts of the city

THE BIGGEST EARTHQUAKES IN HISTORY

856

200,000 people are killed in one of the deadliest earthquakes in history in

Damghan, Iran.

1138

An earthquake in Aleppo, Syria kills 230,000

1556

The deadliest earthquake in history hits Shensi province in China. Almost 1

million people are killed.

1755

The most serious earthquake in Europe hits Lisbon, Portugal. The whole city

is destroyed. About 70,000 people get killed.

1906

The city of San Francisco is hit by a large earthquake. A big fire destroys most

of the city. About 500 people die.

1908

Messina, Sicily is totally destroyed by a large earthquake . About 70,000 peo-

ple are killed.

1923

Tokyo, Japan is destroyed by an earthquake with a magnitude of 8.3 .

150,000 people are killed.

1960

The strongest earthquake ever recorded hits Chile. It reaches 9.5 on the Rich-

ter scale. 20,000 people die.

1964

The strongest earthquake in North America hits Anchorage Alaska. Ocean

waves reach a height of 20 metres. 200 people are killed.

1976

The biggest earthquake ever recorded in China leaves 242,000 people dead.

Earthquakes

destroy =damage , ruin

height =how high something

is

magnitude = how strong or

powerful an earthquake is . It

is measured on the Richter

scale

record =write down, keep

information

serious = dangerous

5

What can earthquakes be caused by . Give some examples

1. ______________________________________________________________________________________________

2. ______________________________________________________________________________________________

3. ______________________________________________________________________________________________

4. ______________________________________________________________________________________________

What do continents move on ? __________________________________________________________________________

What happens when plates come together ? _______________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

Why don’t we hear about most of the earthquakes ? ________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

What is the “Ring of Fire “ ? ____________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

There are two types of waves . Describe them !

How do people cause earthquakes ? _____________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

Earthquakes

6

Body waves Surface waves

Complete the following text with the words from the box !

With a machine called a __________________ , scientists can tell us where an earthquake oc-

curred and its ____________________ . Every earthquake starts at the focus or

_______________ . This can be near the earth’s __________________ or many hundred kilome-

tres in the earth’s ______________ . From here waves travel in all ________________ . The

area directly above the focus is called the earthquake’s _________________ . This is the area

where most ________________ is done. The Richter ______________ tells us how powerful an

earthquake is. The biggest earthquakes ever __________________ on earth were at 9.5 on this

scale. When an earthquake happens _________________ all over the world compare their infor-

mation .

Explain in English :

magma _____________________________________________________________________________________________

____________________________________________________________________________________________________

disaster _____________________________________________________________________________________________

____________________________________________________________________________________________________

tsunamis ____________________________________________________________________________________________

____________________________________________________________________________________________________

collapse _____________________________________________________________________________________________

____________________________________________________________________________________________________

volcano _____________________________________________________________________________________________

____________________________________________________________________________________________________

magnitude ___________________________________________________________________________________________

____________________________________________________________________________________________________

Earthquakes

7

damage surface recorded

crust seismograph hypocentre

seismologists scale epicentre

magnitude directions

TRUE OR FALSE ?

Earthquakes

8

T F

Big earthquakes can be found where plates meet.

The Ring of Fire is around the Atlantic Ocean. Most of the world’s

biggest quakes occur here.

In 1906 many houses in San Francisco burned down because they

were made of wood

Earthquakes that happen on the ocean floor are called tsunamis.

The earth’s crust is thinnest under the continents.

Faults are places where two plates meet. they can be hundreds of

kilometres long.

Earthquakes can also be caused by underground explosions.

Most earthquakes happen after big volcanoes erupt.

When there is a sudden movement in the earth’s crust, energy

moves in the form of waves.

Body waves are fast and travel through all kinds of material

A machine made to find out how strong earthquakes are is called a

hypocentre.

the Richter scale tells you how many people died in an earthquake.

The place above the earth where the most damage is done is called

the epicentre.

Today , it is important to use wood when you build houses or build-

ings.

Write a newspaper report about the picture below !

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

____________________________________________________________________________________________________

Earthquakes

9

Earthquakes

10

1 2

3 4

5

6

7 8

9

10

Across Down

1. city in North America that was destroyed

by a big earthquake

5. centre of an earthquake

6. rock in the inner part of the earth that is

liquid

7. place on the surface of the earth where

the earthquake waves hit first

9. Oberfläche

10. what the continents move on

1. machine that tells scientists how strong

an earthquake is

2. material that is used to build houses and

buildings that are protect people from

earthquakes

3. name of the scientist who made a scale

to measure earthquakes

4. big ocean wave that is caused by earth-

quakes

5. where two plates meet

8. the top part of the earth

Earthquakes

11

1 2

3 4

5

6

7 8

9

10

S

E

I

S

M

O

G

R

A

P

H

A N

R

I

C

H

T

E

R

P

F

P

L

R

M

I

S

A

A

A

C

R

U

S

T

N

G

E

R

E

C

M

N

F

I

F

A

U

L

T

A

S

O

R

C

C

O

N

C

R

E

T

E

E

O

U

T

S

U

N

A

M

I

Earthquakes

12

P O R F S D Y M Q A

D I S A S T E R F Y

Z O E U H H Q A N Z

D C I L R W A V E S

M O S T Z F R K A V

A L M D P L A T E S

G L O V F T F C O R

M A G N I T U D E R

A P R M P V J P J E

P S A Y R Q U Z G D

T E P I C E N T R E

D M H L D R A Z H C

O I T D O I U H G M

A K M B Q O T S K J

I B P G A E C U T L

Find 12 words in the grid that have to do with earthquakes !

Earthquakes

13

P O R F S D Y M Q A

D I S A S T E R F Y

Z O E U H H Q A N Z

D C I L R W A V E S

M O S T Z F R K A V

A L M D P L A T E S

G L O V F T F C O R

M A G N I T U D E R

A P R M P V J P J E

P S A Y R Q U Z G D

T E P I C E N T R E

D M H L D R A Z H C

O I T D O I U H G M

A K M B Q O T S K J

I B P G A E C U T L

Find 12 words in the grid that have to do with earthquakes !