Download EngGr7T2-SS-Geography-TEACHER GUIDE-and - E

Social
Sciences
GEOGRAPHY Teacher's Guide • Grade 7 Term 2
Knowledge
Understand the causes and
effects of volcanoes and
earthquakes.
Investigate the causes and
effects of floods.
Skills
Map reading and
interpretation.
Interpretation of various
articles to answer
questions.
Values
Appreciate how the earth
changes and moves. Show
apathy to victims of natural
disasters.
Resources:
Learner’s Book with activities, pictures and resources relating to volcanoes, earthquakes
and floods, dictionary, atlas, globe, Internet, reference books, a world map.
Teacher preparation:
1. Ensure that you are familiar with the entire module before you begin. Explore each topic with the learners so that they have concise information to successfully use this module. Look at the teaching plan to see how to fit the activities into your week.
2. Study the resources for each lesson and ensure that you have the necessary resources in advance.
3. Some activities may require documents to be printed. Ensure that these are printed in advance. Activities can be made more exciting if the learners have access to the Internet. If individual access is not possible, print the relevant information provided by the hyperlinks for each lesson. The Learner’s Book is needed for each activity.
There are links to the Internet pertaining to the content in the Learner Book. Should the learners not have individual access to the internet, download and print the information for the learners.
4. Prepare your assessment recording sheets carefully at the beginning of the term. Have the activity sheets ready to ensure continuous formal and informal assessment.
5. Whenever there is something to be written, allow the learners to write the answers in their class workbook, unless an activity sheet has been provided. Facilitate the comprehension tasks and keep the correct time management for each task.
Content and concepts:
• Discuss the causes and effects of volcanoes, earthquakes and floods.
• Explain the structure of the earth and how the crust moves.
• Investigate the location of volcanoes around the world and how volcanoes occur.
• Discuss the occurance of earthquakes and the aftermath of famous earthquakes around
the world.
• Explain the cause of floods, tropical cyclones and the effect of tsunamis.
• Investigate how to reduce the impact of floods in a manner that comliments the natural
environment.
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1
Volcanoes, earthquakes and floods
The structure of the Earth
http://science.howstuffworks.com/nature/29595-100-greatest-discoveries-platetectonics-video.htm
The Earth comprises of a crust (a hard outer layer like the skin of an apple), a mantle (a layer
of very hot and dense rock that flows and moves) and a core (the hot centre of Earth) that
http://science.howstuffworks.com/nature/29595-100-greatest-discoveries-plateis believed to be made entirely from metal.
tectonics-video.htm
A hard layer called the crust covers the Earth. This layer is the outermost layer of rock
that covers the Earth. The crust is thinner in some places than in others. Mountains are How the crust moves
areas where the crust is thick. This crust is not one large solid piece; it consists of many The crust is not one large solid piece of rock. It consists of many smaller pieces that are
smaller pieces that are called ‘tectonic plates’ which are thousands of kilometres in length. called ‘tectonic plates’ which are thousands of kilometres in size. These tectonic plates
These tectonic plates float on the underlying layer of magma and exert pressure as float on the underlying layer of magma and exert pressure as they move. The edges of the
tectonic plates are called ‘plate boundaries’. The tectonic plates move on the layer of hot
they move.
slow-moving magma that lies underneath the crust. When the plates move, they push and
The mantle comprises of layers of hot slow-moving magma, which causes the tectonic pull against each other causing pressure or sudden shifts.
plates to move. This movement causes earthquakes and volcanic eruptions.
There are seven large plates and many smaller plates that move very slowly each year. The
The core is the hottest layer of the Earth, comprising of an outer and inner core. Scientists plates that lie beneath the continents are called continental plates and the plates that lie
believe that the outer core is made up of nickel and iron, whilst the inner core is largely beneath the oceans are called oceanic plates.
iron. The outer core is more liquid than that of the inner core. The temperatures within the
Eurasian Plate
Eurasian Plate
core range from 5000 – 7000 degrees Celsius. The pressure for the rest of the Earth causes
the inner core to be mostly solid, even though the temperature of the core is hot enough
North American Plate
to melt the iron.
crust 0-100
km thick
] lithosphere
(crust and
upper-most
solid mantle
Asthenosphere
mantle
outer
core
inner core
2900 km
5100km
liquid
solid
Activity 1
a) Name the three main layers of the Earth.
(1)
b) Describe a tectonic plate.
(2)
c) How does magma contribute to earthquakes?
(1)
d) Describe the structure of
the core.
(5)
Cocos Plate
Nazca
Plate
Pacific Plate
Antarctic Plate
Total:(9)
http://www.nhm.ac.uk/nature-online/earth/plate-tectonics/index.html
African Plate
Indo-Australian Plate
6378 km
The internal structure of the Earth
South American Plate
Tectonic plates
The tectonic plates
The edges of the tectonic plates are called ‘plate boundaries’. New crust is formed and old
http://science.nationalgeographic.com/science/earth/the-dynamic-earth/plate- crust is returned to the core at these boundaries. The process of the Earth’s crust being
formed and returned to the core can take about 100 million years.
tectonics-article/
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2
These plates meet in different ways:
h
c
tren
c
i
an
asin
oce
sediment
scraped off
subducting
plate
rc b
k-a
c
a
b
oceanic crust
Convergent boundaries:
These occur when two tectonic
plates push against each other
and one plate is forced upwards.
This movement causes the
formation of mountains or
volcanoes. The other plate sinks
back into the core and melts.
Earthquakes can occur along this
type of boundary.
Divergent boundaries:
These occur when the tectonic
plates pull away from each other.
The crust breaks apart. The
space that remains is called a rift.
Magma seeps up to fill the rift and
so new crust is made.
partial melting of
mantle
Transform boundaries:
This type of boundary is where two plates meet and move against each other horizontally,
in different directions. As they move, neither plate is displaced up or down. This movement
causes a build up of energy, which may be released in a sudden movement which can
cause an earthquake.
Activity 2
a) Define a plate boundary.
(1)
b) How do the tectonic plates move?
(1)
c) Name and describe three areas where tectonic plates meet.
(6)
d) List the names of three tectonic plates.
(3)
e) Describe the difference between continental and oceanic tectonic
plates. (2)
f ) Explain why the Great Rift Valley in Africa is a good example of
divergent convergence.(3)
Total: 16
Volcanoes
Rift Valley
(African Rift Valley)
Locations around the world
A volcano allows molten rock form the mantle to flow out on to the Earth’s surface through
the Earths crust, in the form of lava. Currently, there are approximately 1500 active volcanoes
around the world. A small portion of these volcanoes are located beneath the oceans.
Indian
Plate
New Ocean Basin
(Red Sea)
African
Plate
http://science.howstuffworks.com/nature/231-how-volcanoes-work-video.htm
A volcano erupting beneath the ocean
Diagram of the African plate, showing the
East African Rift zone.
Mature Ocean
(Atlantic)
Mid-Ocean Ridge
http://video.nationalgeographic.com/
video/news/west-mata-submarinevolcano-vin?source=searchvideo
fact file
Sediments
Crust
Mantle
Lakes of the Great Rift Valley as seen from
space.
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There are
1500
active
volcanoes
world wide
3
Volcanoes are often found near the
edges of the tectonic plates that cover
the surface of the Earth.
Volcanoes can erupt
through the same fault or
vent over a long period of
time. A crater forms at the
top of the volcano. After
each eruption, lava coats
the edge of the crater and
builds a cone as the lava
cools.
A volcanic eruption
A famous volcanic eruption was that of Mount St Helens in the United States of America. The
eruption occurred on 18 May 1980. The eruption destroyed approximately 250 homes and
killed 57 people. The eruption removed almost 400m of the volcano leaving a horseshoe
shaped crater in the volcano.
http://www.discovery.com/video-topics/other/other-topics-volcano-videos.htm
R
RE
IN
OF
Diagram of a volcano
FI
G
The Ring of Fire is a ring of volcanoes that is found in the Pacific Ocean. There are
approximately 450 volcanoes in this area. There are frequent earthquakes and volcanic
eruptions in this area.
Why volcanoes occur
The pressure caused by the movement of magma beneath the Earth’s crust can force
magma up through faults in the Earth’s surface. This movement of magma causes a volcano.
When the magma reaches the Earth’s surface, it is called lava. As the lava pours onto the
surface, the lava emits poisonous gases. The heat of the lava causes clouds of steam in the
atmosphere. The force of the pressure of a volcano can cause rocks, ash and volcanic dust
to be blasted into the air. http://video.nationalgeographic.com/video/volcano-lava
© e-classroom 2014
From top left clockwise, Mount St Helens before, during
and after eruption.
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4
Activity 3
a) Where do volcanoes occur? (3)
b) Describe a volcano. (3)
c) Explain the difference between magma and lava.
(1)
d) Why do volcanoes occur?
(2)
e) Describe the Ring of Fire.(2)
e) Briefly describe the eruption of Mount St Helens.
(4)
Total: 15
world’s earthquakes and 81% of the world’s largest earthquakes occur along the Ring of Fire.
The December 2004 earthquake just off the coast of Sumatra which caused a devastating
tsunami, was in the Alpide belt. This belt has 17% of the world’s largest earthquakes.
Instruments called seismographs record earthquakes. The recording they make is called
a seismogram. The seismograph has a base that sets firmly in the ground and a heavy
weight that hangs free. When an earthquake causes the ground to shake, the base of the
seismograph shakes too, but the hanging weight does not. Instead, the spring that it is
hanging from, absorbs the movement. The difference in position between the shaking part
of the seismograph and the motionless part is what is recorded.
Eurasian Plate
Eurasian Plate
North American Plate
Earthquakes
Earthquakes occur when part of the Earth’s crust moves. The area where the crust moves is
called the ‘fault’ or ‘fault plane’. Large earthquakes occur when the movement is about one
to two metres. A small earthquake occurs when the crust moves in millimetres.
The Earth’s outer surface is broken up into what geologists call ‘plates’. Earthquakes occur
when the plates move under, over or slide past each other. Most earthquakes occur on the
edges of these plates that make up the Earth’s crust. The location below the Earth’s surface
where the earthquake starts is called the ‘hypocentre’, and the location directly above it on
the surface of the Earth is called the ‘epicentre’.
Cocos Plate
Nazca
Plate
South American Plate
African Plate
Indo-Australian Plate
Pacific Plate
Antarctic Plate
Tectonic plates
fault plane
epicentre
An earthquake is a sudden, rapid shaking of the Earth caused
by the release of energy stored in rocks. This energy can be built http://science.howstuffworks.com/nature/236-how-earthquakes-work-video.htm
up and stored for many years and then released in seconds or
minutes. Many earthquakes are so small that humans cannot http://video.nationalgeographic.com/video/101-videos/earthquakefeel them. Some have caused great destruction and killed 101?source=relatedvideo
many people.
http://www.nhm.ac.uk/nature-online/earth/volcanoes-earthquakes/earthquakes/index.html
Sometimes an earthquake has ‘foreshocks’. These are smaller
earthquakes that happen in the same place as the larger
A seismograph
earthquake that follows. The largest, main earthquake is called the ‘mainshock’. Mainshocks
The size of an earthquake depends on the size of
always have aftershocks that follow. These are smaller earthquakes that occur afterwards
the fault and the amount of slip on the fault. A
in the same place as the mainshock. seismogram recording made on seismographs
will determine how large the earthquake was. There are two major regions of earthquake activity on the planet. One region is called the
circum-Pacific belt and is also known as the ‘Pacific Ring of Fire’, which encircles the Pacific
A short wavy/undulating line that doesn’t
Ocean. The other region is called the ‘Alpide Belt’, which extends from Java to Sumatra
move very much means the earthquake was a
through the Himalayas, the Mediterranean, and out into the Atlantic.
small earthquake. A long wavy line that moves
a lot means a large earthquake. The length of
The Ring of Fire is a zone where earthquakes happen frequently. As much as 90% of the
the wave depends on the size of the fault,
hypocentre
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5
and the size of the wave depends on the amount
of slip. A Richter scale measures the enormity of an
earthquake based on the semiography fluctuations.
An example of a seismogram
Earthquakes measuring six and above are considered
major quakes. Earthquakes measuring seven and above cause
great damage and kill many people.
fact file
No one
can predict
when an
earthquake
will occur
Other famous earthquakes:
22 May 1960, Chile: quake measuring 9.5
on the Richter scale – struck Santiago and
Concepción, triggering tidal waves and
volcanic eruptions.
Earthquake Rocks China!
An earthquake of 7.8 magnitude hit
China’s Sichuan province on Monday, May
12, 2008.
Within one week of the massive quake, at
least 32,000 people were reported dead
and more than 200,000 injured. Hundreds
of aftershocks rippled through the region
after the quake, causing landslides and
other damage.
Unlike hurricanes, no one can predict
when an earthquake will hit. There is no
warning and no evacuation time. The U.S.
Geological Survey (US
GS) says
that at
least one
earthquake
happens
somewhere
on the
globe every
day, usually
small and
in remote
regions where few people live. But when
big earthquakes hit in heavily populated
areas, it can easily become a catastrophe.
China Mourns Quake Dead
MONDAY, MAY 19, 2008 Aljazeer
With the toll from the quake standing at more than 32,000, China’s leaders have declared
three days of national mourning for the dead.
Many more are still listed as missing and officials say the final toll could rise above 50,000.
As the mourning period began on Monday, state media reported that more than 200
recovery workers had been buried by landslides over the past two
days in the disaster zone.
The official Xinhua news agency gave no details of where the incidents
happened, but the report highlights the continued danger faced by
Aftershocks
relief teams racing against time to find survivors.
and disease
On Sunday, at least three people were killed in a 6.0-magnitude
kill many
aftershock.
The aftershocks and heavy rain have put recovery crews on heightened
survivors
alert, fearful further strong tremors could bring down already
after an
weakened buildings.
But while recovery efforts are switching to focus on clearing up the earthquake
tonnes of debris, a few survivors are still being pulled out alive from
collapsed buildings.
The authorities, meanwhile, are also battling to prevent the outbreak of disease, with the
risks heightened by the rotting carcasses of 12.5 million livestock and poultry.
“Combating epidemics is the most urgent and the biggest task facing us right now,” Wei
Chaoan, Vice-Minister of Agriculture, said on Saturday.
The World Health Organisation said that the lack of safe drinking water or proper waste
disposal along with cramped conditions in temporary shelters was “conducive” to outbreaks.
“Preventing communicable disease outbreaks is the key public health issue now facing the
People’s Republic of China,” the UN body said in a statement.
fact file
28 March 1964, Alaska: quake followed
by tsunami – claimed 125 lives, caused
millions in property loss. Measuring 9.2
on the Richter scale, it was felt over a
large area of Alaska and in parts of Yukon
Territory and British Columbia.
http://guide.sacbee.com/2010/06/17/4218/earthquakes-rock-china.html
Read the following articles.
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6
Floods
Activity 4
a) In which country and on which continent is Sichuan located? (2)
b) The map below shows the Sichuan Earthquake. Indicate the location of Sichuan on
the world map. (1)
A flood causes a great amount of damage. Heavy rain causes rivers and dams to flood,
damaging homes and other buildings, removes bridges and roads, devastates food crops
and kills livestock. Floods can be devastating to the local population that live in areas of
the flood.
Unusually heavy rains generally cause floods when the natural watercourses fail to contain
the amount of water accumulated. Floods are also caused by other natural phenomena
such as tropical cyclones and tsunamis.
Sichuan Earthquake
http://www.nhm.ac.uk/nature-online/earth/volcanoes-earthquakes/floods/
http://video.nationalgeographic.com/video/101-videos/floods
World Map
Tropical cyclones
Tropical cyclones are also known as ‘typhoons’ and ‘hurricanes’. A cyclone is a storm system
characterised by a low-pressure centre and powerful thunderstorms that produce strong
winds and flooding rain. A tropical cyclone feeds on heat released when moist air rises,
resulting in condensation of water vapour contained in the moist air.
descending air
fact file
eye
eyewall
c) What was the size of this earthquake?
(1)
d) There were many aftershocks reported after the earthquake. What further
damage did these aftershocks cause? (1)
e) Can earthquakes be predicted? (1)
f ) Why is it more catastrophic when an earthquake hits a densely populated area,
than when an earthquake hits a less populated area? (2)
g) Provide the abbreviation for the World Health Organisation.
(1)
h) What role did the WHO play in the aftermath of the Earthquake in Sichuan? (1)
Total: (10)
© e-classroom 2014
warm, moist air
low pressure
Although
cyclones are
predicted, people
often choose
to ignore the
warnings.
A cross section of a cyclone
Cyclones circulate counter clockwise in the Northern Hemisphere and clockwise in the
Southern Hemisphere.
Cyclones, hurricanes and typhoons can be predicted several days in advance. These
disasters are usually more destructive than floods.
Possible damage by cyclones:
High winds cause major damage to infrastructure and housing. They are generally followed
by heavy rains and floods and by tidal waves in flat coastal areas.
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7
Storm surges develop over large bodies of warm water, and lose their strength if they move
over land. This is the reason coastal regions can receive significant damage from a tropical
cyclone, while inland regions are relatively safe from receiving strong winds.
Storm surges can produce massive coastal flooding (up to 40 kilometres from the coastline)
and heavy rainfall can produce inland flooding.
Accurate landfall predictions of a cyclone can give only a few hours’ notice to threatened
populations. People generally opt to wait until the very last minute before abandoning
their home and possessions. Deaths from drowning in the high tides and sudden flooding
and material losses are therefore often very high.
Information adapted from:
http://www.ifrc.org/what/disasters/about/types/hydrometeorologic/hurricanes.asp
fact file
The World
Meteorological
Organization
names the
hurricanes
How are hurricanes/cyclones named?
All hurricanes are given names to help identify and track them as
they move across the ocean. There can be more than one hurricane
at a time and without naming them, we could get confused between
each storm.
Hurricane classification
Hurricanes are classified into five categories based on their current maximum wind
speed. This rating scale is called the Saffir-Simpson Hurricane Scale, named after Herb
Saffir and Robert Simpson, who developed it.
Category 1 -- Winds 119 – 153 km/hMinimal damage
Category 2 -- Winds 154 – 177 km/hModerate damage
Category 3 -- Winds 178 – 209 km/h Extensive damage
Category 4 -- Winds 210 – 249 km/hExtreme damage
Category 5 -- Winds over 249 km/h Catastrophic damage (these are very rare)
There are very few Category 5 storms; most storms that achieve Category 5 status only
hit Category 5 status for a very short time, then the winds subside to a less powerful
level. Some of the strongest recent hurricanes (Atlantic Ocean tropical cyclones) that hit
Category 5 status include:
Hurricane Felix (September 2007) -- Caribbean
Hurricane Dean (August 2007) -- Gulf of Mexico, Yucatan Peninsula, Mexico, Caribbean
Hurricane Wilma (October 2005) -- Gulf of Mexico, Yucatan Peninsula, Mexico, Cuba, and
Southern Florida
Hurricane Rita (September 2005) -- hit Texas, Louisiana
Hurricane Katrina (August 2005) -- hit southern Louisiana, Mississippi and Alabama
Hurricane Isabel (September 2003) -- hit North Carolina, Maryland, Delaware, Virginia,
and Washington, D.C.
Hurricane Mitch (October 1998) -- hit Honduras, Nicaragua, El Salvador, and Guatemala
Hurricane Andrew (August 1992)-- hit south-eastern Florida and south-eastern Louisiana
Cyclone Nargis
On 2 May 2008 tropical
cyclone Nargis hit the coast
An Australian meteorologist began giving women’s names to tropical of Myanmar and devastated
storms before the end of the 19th century. In 1953, the US National large parts of the low-lying
Weather Service, began using female names for storms. By 1979, Irrawaddy delta. Winds
both women and men’s names were used.
exceeding 190 kilometres
One name for each letter of the alphabet is selected, except for Q, U and Z.
per hour ripped through
the Myanmar’s biggest
These are the hurricane names used in 2007:
city Yangon for more than
Andrea, Barry, Chantal, Dean, Erin, Felix, Gabrielle, Humberto, Ingrid, Jerry, Karen, Lorenzo, ten hours. Homes were
Melissa, Noel, Olga, Pablo, Rebekah, Sebastien, Tanya, Van, Wendy.
flattened, structures
damaged, trees uprooted
The World Meteorological Organization uses six lists in rotation to name hurricanes. The and power lines collapsed.
same lists are reused every six years. The only time a new name is added is if a hurricane is In rural parts of the country
very deadly or costly. Then the name is retired and a new name is chosen.
up to 95 per cent of homes
were demolished.
Some of the retired names are:
Katrina, Andrew, Rita and Wilma
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8
Activity 5
Look at the pictures below. These pictures tell the devastating story of cyclone Nargis
that hit Myanmar on 2 May 2008. List the ways in which the people of Myanmar were
affected by the cyclone.
(9)
Tsunamis
Japan’s most powerful earthquake since records began, struck the northeast coast,
triggering a massive tsunami. The quake was the fifth largest in the world since 1900.
JAPAN
8.9 magnitude
earthquake
Depth: 24.4 km
http://science.howstuffworks.com/nature/230-how-tsunamis-work-video.htm
http://www.nhm.ac.uk/nature-online/earth/volcanoes-earthquakes/tsunami/how-tospot-a-tsunami/index.html
On March 11, 2011, measuring at 8.9 on the Richter Scale by the US Geological Survey, the
tsunami struck at 05:46 GMT at a depth of about 24km.
A 10m-wave struck Sendai, burying farmland and sweeping cars across the airport’s
runway. Fires broke out in the centre of the city. Cars, ships and buildings were swept
away by a wall of water after the 8.9 magnitude tremor, which struck about 400km (250
miles) northeast of Tokyo. Japan’s NHK television showed a massive surge of debris-filled
water reaching far inland, consuming houses, cars and ships. Motorists could be seen
trying to speed away from the wall of water.
The tsunami rolled across the Pacific Ocean at 800km/h before hitting Hawaii and the US
West Coast, but there were no reports of major damage from those regions.
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9
Thousands of people evacuated coastal areas in the states of California, Oregon and
Washington. Waves of more than 2m were recorded near California’s Crescent City. A tsunami
warning extended across the Pacific to North and South America, where many other
coastal regions were evacuated, but the alert was later lifted in most parts, including the
Philippines, Australia and China.
Activity 6
Answer the following questions:
1) True or False
a) The Earthquake caused the most damage in Japan. b) A tsunami was triggered by the Earthquake.
c) The epicentre of the Earthquake took place at sea.
d) The Earthquake occurred on the Pacific tectonic plate.
(4)
2) Why was the chance of surviving the Japanese tsunami wave highly
unlikely? (2)
3) Look at the picture:
a) How do you know that this tsunami wave was powerful and
forceful?(2)
b) What type of debris can be seen in the tsunami wave?
(2)
Total: 10
The wave from a tsunami crashes over a street in Miyako City, Iwate
The terrifying wall of water that smashed into northeast Japan was unstoppable. It wasn’t
the Earthquake but the following tsunami that caused most devastation in Japan.
The tsunami was triggered by an 8.9-magnitude earthquake. This earthquake took place
around 400 kilometres from Tokyo, off the coastal city of Sendai.
fact file
Tsunamis are
triggered by
an earthquake
Reducing the impact
The damaging effects of a flood are worsened by the destruction of the natural environment.
Dunes, wetlands and barrier islands can protect the land against the effects of a coastal
storm. Forests and floodplains natural absorb floodwaters. Deforestation, alien vegetation,
land degradation and the diversion of rivers are factors that can contribute the damaging
effect of floods.
The tremor itself was a result of the Pacific tectonic plate
submerging beneath the North American and Eurasian
tectonic plate. The tectonic plate, could not withstand the
pressure of submerging. When it cracked, the upper part of the
Pacific plate rebounded, causing the sea level to rise up to 4
meters along a 100 to 150 kilometre fracture zone. This resulted
in a wave that travelled at high speed through the ocean
towards the shore.
http://www.nhm.ac.uk/nature-online/earth/volcanoes-earthquakes/tsunami/how-anearthquake-causes-a-tsunami/index.html
Deforestation
The tsunami reached a wave height of approximately 10 meters. It is not only the height of
the wave that is so dangerous, it is the wavelength of 200 meters that unfolds the deadly
impact as a huge volume of water filled with debris, cars, ships and even parts of houses
crashes onto shore. The chances of surviving this are highly unlikely.
© e-classroom 2014
Land degredation
Activity 7
In a paragraph, explain what can be done to resolve each of the factors that contribe
to the damaging effects of a flood. (4)
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10
Memos
Activity 1
Activity 2
Revise the three main layers of the earth and the structure of the core. Explain how
the tectonic plates move due to the cycling motion of the mantle and how magma
contributes to earthquakes.
a) Define a plate boundary.
Answers:
a) Name the three main layers of the earth.
(1)
(2)
A tectonic plate is a smaller piece of the crust, which can be thousands of kilometres in length.
The tectonic plates float on the underlying layer of magma and exert pressure as they move.
d) How does magma contribute to earthquakes?
(1)
The mantle comprises of layers of hot slow-moving magma, which causes the tectonic plates to move. This movement causes earthquakes and volcanic eruptions.
e) Describe the structure of the core.
(5)
The core is the hottest layer of the earth, comprising of an outer and inner core. Scientists believe that the outer core is made up of nickel and iron, while the inner core is largely iron.The outer core is more liquid than that of the inner core.
The temperatures within the core range from 5000 – 7000 degrees Celsius.
The pressure for the rest of the earth causes the inner core to be mostly solid, even though the temperature of the core is hot enough to melt the iron.
(1)
The edges of the tectonic plates are called ‘plate boundaries’
b) How do the tectonic plates move?(1)
Crust, mantle and core
c) Describe a tectonic plate.
Total: (9)
The tectonic plates move on the layer of hot slow-moving magma that lies underneath the crust.
c) Name and describe three areas where tectonic plates meet.
Convergent boundaries: These occur when two tectonic plates push against
each other and one plate is forced upwards. The other plate sinks back into the core and melts.
Divergent boundaries: These occur when the tectonic plates pull away from each other. The crust breaks apart. The space that remains is called a rift. Magma seeps up to fill the rift and so new crust is made.
Transform boundaries: This type of boundary is where two plates meet and move against each other horizontally, in different directions. As they move,
neither plate is displaced up or down. This movement causes a build up of energy, which may be released in a sudden movement which can cause an earthquake.
d) List the names of three tectonic plates.
(3)
Any three of the following:
Arabian plate, Eurasian Plate, South American Plate, Indo-Australian Plate, North American Plate, Antartic Plate, African Plate, Nazca Plate, Pacific Plate, Cocos Plate.
e) Describe the difference between continental and oceanic tectonic plates. (2)
The plates that lie beneath the continents are called continental plates and the
plates that lie beneath the oceans are called oceanic plates.
f ) Explain why the Great Rift Valley in Africa is a good example of divergent convergence.(3)
The Great Rift Valley is a good example of divergent convergence as a divergent boundary happens when two plates pull apart and the crust breaks apart. Magma seeps into the rift and new crust is formed. This rift can cleary be seen on photograph of that area of Africa.
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(6)
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Total: (16)
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Activity 3
a) Where do volcanoes occur? (3)
Volcanoes are often found near the edges of the tectonic plates that cover the surface of the earth, both on land and underwater.
b) Describe a volcano.
(3)
A volcano allows molten rock from the mantle to flow out on to the earth’s surface through the earths crust, in the form of lava.
Activity 4
c) Explain the difference between magma and lava.
Read the articles below and answer the questions that follow.
(1)
a) In which country and on which continent is Sichuan located? When the magma reaches the earth’s surface, it is called lava.
d) Why do volcanoes occur?
(2)
The pressure caused by the movement of magma beneath the earth’s crust forces magma up through faults in the earth’s surface. This movement of
magma causes a volcano.
e) Describe the Ring of Fire.
(2)
China, Asia
b) The map below shows the Sichuan earthquake. Indicate the location of Sichuan on the world map beneath this map. (1)
Ensure that the learners have the correct location on the map.
c) What was the size of this earthquake? The Ring of Fire is a ring of volcanoes that is found in Pacific Ocean. There are approximately 450 volcanoes in this area. There are frequent earthquakes and
volcanic eruptions in The Ring of Fire.
7.8 in magnitude
e) Briefly describe what happened during the volcanic eruption of
Mount St Helens.
Landslides occurred
(4)
The eruption occurred on 18 May 1980 in the United States of America.
Approximately 250 homes were destroyed and killed 57 people. The eruption removed almost 400m of the volcano leaving a horseshoe shaped crater in the volcano.
Total: (15)
(2)
(1)
d) There were many aftershocks reported after the earthquake. What further damage did these aftershocks cause? (1)
e) Can earthquakes be predicted? (1)
No
f ) Why is it more catastrophic when an earthquake hits a densely populated area,
than when an earthquake hits a less populated area? (2)
As there are more people in the area, more people are hurt. There are more buildings that are damaged.
g) Provide the abbreviation for the World Health Organisation.
(1)
WHO
h) What role did the WHO play in the aftermath of the earthquake?
in Sichuan? (1)
The WHO assisted in containing epidemics that might have occured after
the earthquake.
Total: (10)
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12
Activity 6
Activity 5
Look at the pictures below. These pictures tell the devastating story of cyclone Nargis
that hit Myanmar on 2 May 2008. List the ways in which the people of Myanmar were
affected by the cyclone. (9)
These will be the learners own answers including:
Answer the following questions:
1) True or False
a) The earthquake caused the most damage in Japan. False
b) A tsunami was triggered by the earthquake.
True
c) The epicentre of the earthquake took place at sea. True
d) The earthquake occurred on the Pacific tectonic plate.
True (4)
2) Why was the chance of surviving the Japanese tsunami wave highly unlikely?
The force of the water was too great to survive and the water also
contained debris that was hazardous.(2)
3) Look at the picture:
a) How do you know that this tsunami wave was powerful and forceful?
The wave crashed into buildings and over roads. Cars had been
overturned and swept away.(2)
Flooding
Lack of food
Damaged homes
b) What type of debris can be seen in the tsunami wave?
Vehicles, trees, boats. (2)
Damaged roads
Unsafe drinking water
Total: (10)
Loss of belongings
Loss of farm land
Displaced families
Activity 7
Possibilty of epidemic outbreak
Total: (9)
In a paragraph, explain what can be done to resolve each of the factors that contribute
to the damaging effects of a flood. (4)
Learners own answer using the following points.
• Remove alien vegetation
• Replant trees in areas that have suffered the effects of deforestation
• Ensure that rivers that have been diverted are properly constructed to contain a
flash flood if it occurs. Dams should be built to withstand the pressure of a large
body of water
• Prevent the degradation of land or rehabilitate land that has been degraded
Total: (4)
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