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Report on earthquakes!
By Holly Low (Year 4)
ANSWERING NEARLY
EVERYTHING YOU WOULD WANT
TO KNOW ABOUT EARTHQUAKES
Introduction
Thousands of earthquakes
hit the earth each year.
Most of them are minor,
but some are very major.
This presentation will
inform you on all types of
earthquakes and will teach
you the key facts you will
need to know about them.
It will also teach you what
to do in an earthquake Photo: www.exploratorium.edu
emergency
What is an earthquake?
An earthquake is the shaking or a shock on the earth’s
surface.
It is the earth’s way of releasing pressure.
Earthquakes usually last only last under one minute
(but there are often aftershocks which feel similar).
Earthquakes can not be predicted, but scientists are
finding a way to do so using new technology.
Earthquakes can cause devastating damage but
sometimes their effects are only minor.
What causes an earthquakes ?
The earth is made up of about 20 plates that move past each other
slowly.
Sometimes the plates fight for room ,to do so, they shift against each
other with great force.
The plates put lots of force onto each other and themselves
When the force is strong enough the crust snaps. The point above
where the crust snaps is called the ‘epicentre’ of the earthquake.
Around the epicentre is where most damage is caused
The energy of the snap travels through the earth as waves of stress,
and when it reaches the top we feel the quake.
A fault is an area of stress where the plates have slid against each
other – this causes a crack in the surface of the earth.
Where do earthquakes occur ?
Earthquakes often occur in an area
known as the ring of fire.
The ring of fire is an area that circles
the Pacific ocean.
The ring of fire is known very well for
it’s numerous earthquakes and
volcano eruptions, it is one of the
world’s main tectonic plates.
More than half of the world’s active
volcanoes out of the water are in the
ring of fire.
Even though the ring of fire is where
most of the major earthquakes
happen, they can still occur in other
parts of the world.
The photograph on the right shows
The San Andreas fault line – this is in
California (on the eastern side of the
ring of fire)
Photo: www.exploratorium.edu/faultline
The Ring of Fire
Diagram: www.geography-site.co.uk/
How are earthquakes measured?
An earthquake is measured by a Richter Scale.
The Richter Scale measures how powerful a quake is.
Charles Richter invented the Richter Scale 1935, it
measures from under 2.0 (hardly felt) too 10.0+
(devastating).
The most recently recorded ‘moderate’ earthquake in
Britain was in February 2008. It’s epicentre was in
Lincolnshire and it measured 5.4 on the Richter Scale. It
was the biggest earthquake to hit England for 25 years!
There was some damage to property and it was felt as far
away as Scotland and London.
The Richter Scale
Descriptor Richter Magnitude Number Damage caused by the Earthquake Frequency of
Occurrence
Micro Less than 2.0 Micro (tiny) earthquakes, people cannot feel these. About 8,000 each day
Very Minor 2.0 – 2.9 People don’t feel these, but seismograms are able to detect them. About 1,000 per day
Minor 3.0 – 3.9 People often feel these, but they rarely cause damage. About 49,000 each
year
Light 4.0 – 4.9 Objects inside houses are disturbed, causing noise. Nothing is About 6,200 each year
damaged.
Moderate 5.0 – 5.9 Buildings that are not built well may be damaged. Light objects inside About 800 per year
a house may be moved.
Strong 6.0 – 6.9 Moderately powerful. May cause a lot of damage in a larger area. About 120 per year
Major 7.0 – 7.9 Can damage things seriously over larger areas. About 18 per year
Great 8.0 – 9.9 Massive damage is caused. Heavy objects are thrown into the air and About 1 per 20 years
cracks appear on the ground, as well as visible shockwaves. Overhead
highways may be destroyed, and buildings are toppled.
Meteoric 10 + There are no records of anything of this size. The vibration is about Unknown
the same as that of a 20km meteor.
Diagram www.wikipedia.org(adapted from U.S. Geological Survey documents)
How often do earthquakes occur?
Thousands of tiny earthquakes hit the earth each day.
Most of them are hardly felt but some can and they can
cause lots of damage.
120 strong earthquakes and 18 major earthquakes rattle
the earth every year. These are far more dangerous and
can cause loads of damage i.e. The Haiti earthquake.
The smaller the magnitude of the earthquake, the more
they happen. But the higher the magnitude the less they
happen.
What damage can a earthquake cause?
Earthquake damage can be very
minor or devastatingly major.
Earthquakes with a magnitude of
under 4.9, a light quake, could
make objects shake and fall over,
causing noise, most of these
quakes are not felt. Nothing will
be damaged.
But quakes over 5.0, a moderate
earthquake, could damage weak
houses, cause destruction over
large areas, cracks appear,
Photo:www.exploratorium.edu
buildings could topple over etc.
How do scientists
record the strength
of a quake?
Scientists record the
strength of a quake
by using a
seismograph or
seismometer. It
measures that power
and length of an
earthquake.
It also helps scientists
to predict when an
earthquake is coming.
Diagram:www.earthquake.usgs.gov
What should you do during an earthquake?
If you live in an earthquake zone, it is important to have an
earthquake plan. Chose a protected area in each room and
prepare an emergency pack. Make sure tall furniture is
attached to the wall and that cupboards have fasteners on
When an earthquake strikes, the main rule of earthquake
protection is to DROP, COVER and HOLD ON. Drop under
something well-built, protect your eyes by holding your arm
to your eyes and hold on.
It is dangerous to go near windows. If you are outside, find an
area away from trees, power cables and buildings. Then drop
to the ground.
More survival information!
If you are in bed, cover your head with a pillow and make
sure you hold on.
If you are in a car, slow down and drive to a safe place.
Stay in the car while the earthquake is happening.
After an earthquake, be prepared for aftershocks and
make sure nobody has injuries or things are damaged.
Check for any fire hazards.
If there are any aftershocks – continue to DROP, COVER
and HOLD ON!
Case Study - Kobe
Facts about Kobe Where is Kobe?
Kobe is a busy city in the south of
Japan
It has a population of 1.5 million
people
It is 429km from Japan’s capital city -
Tokyo
It is one of the biggest and most
important ports in Japan
It is an very important area for many
industries
On Tuesday 17th January 1995 at
5.46am, the city was struck by a Photo: www.cnn.com
horrifying earthquake.....
On Tuesday 17th of January an earthquake measuring 7.2 on the Richter Scale hit the big, bustling city of
Kobe. The earthquake shook for only 20 seconds, but in that time it caused lots of damage. Kobe had a
population of about 1.5 million people, but after the quake over 5,000 people died and 300,000 where left
homeless. It was the largest earthquake in Japan since 1923.
The damage worth was estimated $100 billion. Fires broke out all over the city, causing even more people
to die. Then, things started to get worse when over 1,300 after shocks followed. Lots of old wooden houses
collapsed, the fire burnt down about 7,500 houses. Blocks of houses and flats that were built in the 1960s
remained intact on the top and bottom floors, but the middle floor would collapse. Modern buildings that
were earthquake proof did well and only suffered a little damage. Some of the homeless had to be put in
shelters i.e. Schools, town halls etc. The winter weather of -2 made this a problem, the homeless had to put
up with living in crowded places for a long time. Food, blankets, medical equipment and clean water
supplies were in very short for the first few days.
The earthquakes caused a lot of damage to transport: motorways collapsed, railway lines buckled, stations
were damaged and quays and ports were destroyed. Huge cranes toppled over into the sea when the
ground they were built on liquefied (the port was built on reclaimed ground and when the earthquake
struck, it acted like a thick soup and structures simply collapsed). The industry around Kobe was extremely
disrupted. Electricity and water supplies were affected and telephones lines were damaged. Fresh water
supplies came back in April 1995 and electricity and gas were fully working again by July 1995.
By January 1999, 134,000 new housing units has been built and there were new laws to make buildings and
transport structures even more earthquake proof. More scientific instruments were installed in the area to
check for signs of earthquakes and schools and factories now have earthquake drills.
Photos from the Kobe earthquake
Photos:www.georesources.co.uk
Summary
An earthquake is when two or more of the earth’s plates
push into one another sending up waves.
An earthquakes power and length is recorded by a
seismograph( or seismometer ) and is measured by the
Richter Scale.
Earthquakes can’t be predicted, many of the most serious
earthquakes happen in the ring of fire, a tectonic plate
circling the Pacific ocean.
References
http://www.georesources.co.uk/kobehigh.htm
http://www.bbc.co.uk
http://earthquake.usgs.gov/learn/kids/
http://www.weatherwizkids.com/weather-earthquake.htm
http://www.exploratorium.edu/faultline/index.html
http://www.geographysite.co.uk
www.google.com
http://www.wikipedia.org/
A Short History of Nearly Everything by Bill Bryson
The Usborne Children’s Encyclopaedia
The Usborne Children’s World Atlas
