Download paper 2 revision booklet

Paper 2 revision
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Tectonic landscapes
and Watery world
1
Tectonic Landscapes G.C.S.E Geography.
Earthquake
Volcano
Focus
A violent shaking of the Earth’s crust.
A vent in the Earth’s crust.
Central point of the earthquake deep below the surface where the earthquake starts.
Where the greatest release of energy occurs.
Epicentre
The point on the surface directly above the focus. Greatest effects will be felt. Between
the focus and epicentre energy is absorbed by the rocks.
Waves of energy from an earthquake.
The measure of the strength of an earthquake.
Seismic waves
Magnitude of an
earthquake
Frequency of an
earthquake
Mercalli Scale
Richter scale
Seismometer
How often the earthquake occurs.
Is a measure of the effects of the earthquake.
I-XII
Measure the strength of the cause of an earthquake. According to the amount of energy
released
1-no upper limit.
Measured by a seismograph.
Scientific instrument that measures earthquakes, creates a seismograph.
Mantle
Fold mountains
The zone of molten rock below the crust.
Benioff zone
Magma
Lava
Plates
Oceanic crust
Continental
crust
Continental
margin
Hotspot
Zone of earthquake along the subduction zone.
Hot, molten rock in the Earth’s mantle.
Molten rock expelled by a volcano.
Section of the earths crust.
5-10km thick but is made of relatively high density material.
25-100km thick low density material.
Pyroclastic flow
Trench
Fold mountains
GDP per capita.
Websites
Buckling of the continental plate leading to a long band of highly crumpled crust.
Found at convergent plate boundaries.
The zone of the ocean floor that separates the thin oceanic crust from thick continental
crust.
Very high temperature magma rises from the mantle even though there is no plate
boundary there. If the crust is thin or weak this magma can escape through it to form
volcanoes. If the lava builds up enough volcanic islands are formed. E.g. Hawaiian Islands
in the Pacific Ocean.
A fast flow of hot ash, gas and rocks rushing down a volcano.
Subduction occurs as the more dense oceanic plate is dragged down, beneath the less
dense continental plate, forming a deep ocean trench on the sea bed.
The buckling of plates due to plates colliding.
Gross Domestic Product. Per person.The amount of goods and services a country
produces.
http://scign.jpl.nasa.gov/learn/plate4.htm annimations
BBC bitesize website
http://www.bbc.co.uk/schools/gcsebitesize/geography/platetectonics/volcanorev1.shtml
http://www.montserratvolcanoobservatory.info/ Monserrat volcano
http://www.geographypages.co.uk/mont.htm Montserrat volcano
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Why do plate move?
Plates move because convection currents in the mantle cause magma to rise spread
out and move the crust.
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Plate movement.
What is a convergent plate margin?
Add labels to this diagram
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
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Oceanic plate
Continental plate
Volcano
Plate melting
Magma rising
What happened at a convergent plate margin? For HL students you need to add
explanation of the process (shown in purple)......
Destructive (oceanic meeting continental) Plates move towards each other. The oceanic
plate is less dense therefore subducts under the continental plate. This forms a deep ocean
trench.. At the same time friction and pressure can cause there to be earthquakes in the
subduction zone. The heat from the mantle and the friction causes the oceanic plate to be
destroyed. The cracking of the continental crust due to the pressure allows a path for
the magma to rise. The plate melts in the mantle and liquid magma rises through cracks to
form a volcano. The rising magma contains gas and is highly pressurised so can lead to
explosive eruptions. The collision of the plates also causes severe folding or uplift of rocks
to cause mountain ranges such as the Andes
Collision (continental to continental) continental crust is less dense than oceanic crust so
when two continental crusts meet a slow collision and uplift occurs rather than any
subduction. This results in intense folding, faulting and uplift and lead to the formation of
mountains; the Himalayan fold mountains were formed in this way . There are a few
earthquakes due to the build up of pressure, but no volcanoes as there is no-way for the
magma to escape.
Oceanic to oceanic boundaries Here subduction happens and this build up of pressure in
the subduction zone causes severe earthquakes. The subducting plate also melts and
magma escapes to the surface to form volcanoes. After several eruptions these volcanoes
break to the surface to form Islands.
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What is a divergent plate margin?
Add labels to this diagram



Convection currents
Magma rising
volcano
What happened at a divergent plate margin?
Plates move away from each other because of convection currents in the mantle. This
creates new crust as the magma rises to fill the gap. Where the magma builds up above the
surface of the ocean volcanic oceans are formed. The volcanoes formed at this boundary are
much more gentle than at destructive plate margins. It is normally shield volcanoes that are
formed that have more runny lava.
An example of this is the Mid Atlantic Ridge.
What is a conservative plate boundary?
On this diagram highlight
the
 Focus
 Epicentre
 Seismic waves
 Direction of plate
movement
What happens at a conservative plate boundary?
Plates slide past each other. No volcanoes or new landforms are created occur because no
magma rises and no crust is being destroyed.
Stresses build up in the rocks. When the pressure is released the result is a violent earthquake. An
example is the San Andrea Fault in North America. At the San- Andreas fault both plates are moving
north-west but at different speeds. Instead of slipping smoothly past each other they tend to ‘stick’.
The pressure builds up until suddenly the plates jerk forwards sending shock waves to the surface
triggering a sudden earthquake.
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Distribution of volcanoes and earthquakes.
Why is the distribution of volcanoes and earthquake uneven?
The distribution is uneven because they occur along plate boundaries- make sure
you use terminology such as bands or linear.
Volcanoes and earthquakes occur around the ring of fire.
Volcanoes also occur at hotspots.
Volcanoes and earthquake occur along some continental land masses such as the
edge of North America and South America.
Volcanoes do not occur in the middle of plates.
On the map above highlight Hawaiian hotspot, Mid Atlantic Ridge, Andes,
Himilayas and San Andreas Fault.
Describe the distribution of earthquakes and volcanoes using the map above.
Why are there are no volcanoes at conservative plate
boundaries?
No magma is rising and no subduction is taking place- no magma is rising and no
crust is being destroyed.
What is the difference between the Mercalli and Richter scale.
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Mercalli Scale
Measure the effects of an earthquakeobservational.
Richter scale
Measures the strength (magnitude) of the earthquake.
Uses a seismograph for the measurement.
Mercalli Scale
Richter scale.
Earthquake case study: San Francisco
Causes:
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San Francisco is located on the San Andreas Fault Line which marks the
boundary between the North American and Pacific Plate (a conservative Plate
boundary). As the two plates move past each other, pressure builds up due to
friction. The earthquake occurred due to the sudden release of the built up
pressure. The epicentre of the earthquake was under a mountain known as
Loma Prieta, 10 miles NE of the city of Santa Cruz. The 1989 earthquake
(measuring 6.9 on the richter scale) was the largest earthquake to have hit
California since the 8.2 earthquake of 1906.
Effects:
The effects of the 6.9 earthquake included 67 Deaths, 6,000 Homes damaged
/ destroyed and 2000 people made homeless. As San Francisco is in a HIC
the damage was minimized due to building regulations and seismically
designed buildings.
The areas were the infrastructure was worse effected was The Marina / Bay
District Here the buildings were wooden and not securely attached to their
foundations. The area was also located on an old landfill site, which was
created following the devastation caused by the 1906 earthquake. As a result
of the weak sub-surface sediments, when the ground shook in the 1989
earthquake, the process of liquefaction occurred. This is where as the
ground lost its sheer strength and acted more like a liquid as water moved up
through the sediments resulting in reduced strength and causing buildings to
collapse due to lack of support.
Many of the older (50-100 year old) buildings which were not designed to
withstand earthquakes were most severely damaged. Low-rise building were
also worse affected than taller buildings which swayed with the quake/ ground
motions.
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Additionally, a number of roadways were damaged during
the earthquake, including the collapse of the upper tier of the double-decker
Nimitz Highway (Interstate 80) onto the lower deck, killing and trapping
motorists in their cars. The collapse was caused partly by soil failure and also
the unsuitable design of the supporting piers. A section of the Bay Bridge also
collapsed killing motorists. There was massive economic costs ($4.4 billion)
and damage to infrastructure - electricity / gas and water mains cut
Why would someone live in San Francisco? (or any earthquake prone zone)
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
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Earthquake proof buildings (e.g. Trans-America Pyramid). Counter-weights,
base isolators etc….
Land use planning- trying to limit development in areas with less solid
foundations
Preparation of the population- quake cottage, earthquake drills in school,
emergency kit, koso value
Well prepared and equipped emergency services
Very good economic base in the area…. Apple, Microsoft etc in the Silicon
Valley
Attractive coastal scenery (Half Moon Bay) good for surfing, very good climate
(30 degrees in summer 10 degrees in winter and low rainfall 300-400 mm per
year). Good tourist economy
Big earthquakes happen very infrequently- the benefits outweigh the risk
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Soufriere Hills volcano. Montserrat Caribbean.
25th June 1997 (major eruption) erupted from 1995-1997
Cause of the volcano
Montserrat Soufriere Hills. 25th June 1997 (major eruption, pyroclastic flow)
erupted from 1995-1997
The North American plate is subducting under the Caribbean plate, which is caused by
convection currents in the Earth’s mantle; this plate boundary is destructive. The
convection currents pull the plate underneath, where intense heat and friction melt it. The
newly melted plate is less dense than the surrounding rock, so it rises up, and is forced
through cracks to the surface. This formed the volcanic island of Montserrat, and is also
what causes earthquakes and volcanic eruptions. The eruption occurred because, over
the course of many years, lava (specifically andesite) from the destruction of the North
American plate built up, forming a dome on the side of the volcano, which eventually
became too heavy, and the dome collapsed on itself. Upon collapse, the dome released
a thick cloud of ash, which rose quickly to 10km, and was deposited over the island by
strong winds. The collapse also caused pyroclastic flows, which can destroy everything in
their path which travelled down the Tar River valley.
.
Montserrat is a LIC: GDP per capita $3,400.
Effects on people and the economy
19 people died- there should not have been this death toll because of the evacuation
procedure and exclusion zone but some people were in the exclusion zone and thought
they would here the sirens, but they did not. Additionally, some farmers stayed to look after
their farms and did not leave the zone as instructed.
People were injured. (burns to feet from walking over the hot ash deposits)
The capital Plymouth was abandoned.
Half of the 11,000 inhabitants fled the island.
People were evacuated out of the exclusion zone to live in make shift shelters in the north.
3000 went to Antigua an island near by. 4,000 went to the UK and the rest to the USA.
Loss of farmland and farm animals therefore a reduced output of GDP.
Destructive of infrastructure, e.g. roads, hotels therefore a drain on resources during
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rebuild.
Loss of opportunities e.g. tourism, export of raw materials
Effect on buildings
Villages were buried in ash (e.g. Dyer, Windy Hill and Harris). The villages of Farm and
Trant were completely buried in ash flow deposits. Everything made of wood was burnt.
100-150 houses were destroyed by fire and rocks up to 5m in size.
Effect on transport
Transport: The airports and seaports were closed. This badly affected the tourist industry- it
was not until the new Gerald’s airport was opened July 2005 (8 years after eruption) that
international air travel could resume. The tourist industry is still suffering with only a few
cruise ships that visit to look at the volcano.
The intense heat burnt the tyres of cars.
Effects on the environment
Two thirds of the island covered in ash.
Many rivers were blocked causing flooding.
Trees were destroyed.
Deposited nearly filled valley such as Mosquito Ghant.
More people in the north put pressure on the natural resources in this area.
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Social economic and environmental reasons for living near
volcanoes: use named examples.
Economic reasons
Social reasons
Environmental
reasons
Some volcanoes are popular tourist areas. Mt Etna in
Sicily attracts thousands of tourists. Jobs are available
such as tour guides and hotel staff.
Some people in LICs can’t afford
to leave. Indonesia where volcano
Mt Merapi is. Because of the fertile
soils their jobs are located in that
area.
People like the
attractive landscape
such as in Sicily where
Mt Etna is located.
Cheap geothermal energy.
It is so cheap some pavements in Reykjavik, Iceland
are heated.
28% of the electricity in Iceland is from geothermal
energy.
People believe that the chance of
the volcano erupting is very low.
Volcanoes can remain dormant for
hundreds of years so people think it
is worth the risk.
Minerals such as tin, silver, gold, copper and diamonds
in some volcanic rocks.
Volcanic soils are fertile. Good for agriculture. e.g.
Wine growing, Naples Italy: Volcano Vesuvius.
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How can the effects of a volcano be reduced?
Before the event: Prediction and preparation.
Prepare for the volcano.
 Evacuation procedures in place. Emergency sirens warned people of the
eruption.
 Emergency services were trained to know that to do.
 Hazard zone maps were drawn up to identify areas most likely to be affected.
Predict the volcano. Try to forecast the eruption by monitoring the eruption.
 Seismic surveys measure the earthquakes.
 Dome surveys, measured the growth of the dome.
 Gas monitoring measured the changes in gases.
What can be done to reduce the effects after a volcano has erupted:
 Explosives can disrupt lava flow- in 1996 the Italian army detonated 7,000 kg
of miming explosives to successfully block a lave flow leading from Mt. Etna
to villages below
 Construction of earth walls to deflect lava flow. During the 1995 eruption in
Kilauea (Hawaii) temporarily diverted lava flows from 2 plantations
 Spraying large volumes of water can cool an advancing flow.
 MVO Montserrat Volcano Observatory was set up to monitor the volcano.
Early warning for  evacuation.
Disaster kits  to help people after the event.
Education of the public  to reduce deaths
Rescue services in place  to reduce deaths.
Monitoring and forecasting  So that evacuation can happen at the right time.
Case study of preparation- Mt Rainier, Washington State, USA
•
Due to being so close to the Seattle-Tacoma Metropolitan Area, 14,411 foot
tall Mount Rainier is the most dangerous volcano in the continental United
States.
What the do to prevent a disaster
• Monitoring of the volcano by The USGS- look at historic records, GPS
mapping to check for any bulges in the volcano, gas sampling- changes can
indicated changes in the magma below
• Evacuation plans- routes through the park. More than 150,000 people reside
on the deposits of previous lahars in the Seattle- Tacoma metropolitan area.
• Because of the higher level of risk from lahars in the Carbon and Puyallup
River valleys, the USGS have installed a lahar-detection and warning system.
The system that detects the ground vibrations of a lahar.
• Land use planning- limiting settlement along river beds as this is where the
lahars will flow , spraying lava to cool it down, digging ditches to divert the
flow away from areas at risk
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Examples of tectonic landscape questions
Explain the processes at a Divergent Plate Boundary (4 marks)
Remember - here the focus needs to be on procceses:
1 - Show understanding of what a Divergent Boundary is (what happens to
the plates)
2 - try and name an example
3 - focus on the processes - i.e. divergence, magma rising, new crust being
created, volcanism and earthquakes.
Possible Answer
At a divergent plate boundary the plates are moving away from each other as
a result of convection currents which operate in the mantle. Here hot magma
rises to the surface and spreads out pulling the plates apart, forming a ridge.
Magma fills the gap in the ridge, creating new crust and causes volcanic
eruptions. Along a ridge, such as the Mid-Atlantic Ridge, both earthquake and
volcanic activity are experienced as a direct result of the plate movement.
Why is volcanic activity occuring in the middle of the Pacific Plate? (4 marks)
The Hawaiian Islands are located in the middle of the Pacific Plate. They are
located here due to the presence of a hotspot. This is where a plume of heat
rises up from the mantle and melts the overlying plate which is thinner than
usual. As the magma is lighter it rises up and erupts onto the surface, forming
a volcano. Lava builds up over time, eventually creating an island above sea
level. The plate continues to move slowly away from the stationary 'hot spot'
due to convection currents in the mantle so the volcano becomes inactive but
a new volcano will form above the hotspot, eventually forming a series of
volcanic islands.
Explain why people continue to live in areas of volcanic and earthquake
activity. Use examples in your answer (5 marks)
Advice:
The question asks examples - if you only give one example you will lose a
mark.
Each point you make must include specific points related to an example.
Remember - this question ask for reasons for living in BOTH areas of volcanic
and earthquake activity - you must refer to both to access the full marks.
Possible Model Answer (look for the explanation and the example)
Some people continue to live in volcanic areas as they cannot afford to move.
Others continue to live in these areas as the potential for economic benefits
outweighs the risk. As well as precious minerals like gold being mined in
these areas, these areas provide job opportunities due to their popularity with
tourists. Major attractions include the Old Faithful geyser in Yellowstone
National Park (USA) and the Blue Lagoon (Iceland). In Iceland alone, tourism
provides over 5,000 jobs. The fertility of many volcanic soils, due to
weathered ash, also provides opportunities for economic gain through
farming. Many farms thrive on the slopes of Mt Etna where olives, grapes and
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citrus fruits are grown. Improvements in technology help to explain why many
continue to live in areas of earthquake activity. Many HICs such as Japan and
the USA have clear disaster plans in place and carefully designed earthquake
proof buildings like the Transamerica Pyramid in San Francisco.
Outline the economic reasons for people continuing to live in areas prone to
volcanic activity (4 marks)
Advice
The command word is outline and often these questions are marked out of 4.
Each point with gain a mark. However you must include specific points about
an example, if not you will only gain two marks In the suggested answer
below make sure you can identify (i) the economic gain (ii) the example
Possible Answer:
Areas prone to volcanic activity can bring many economic gains which attract
people. Precious minerals such as gold, diamonds and sulphur are often
found in abundance in these areas such as the Philippines (Mt Pinabubo) and
Sicily (Mt Etna), where farmers make a living from crops such as olives,
grapes and citrus fruits. The attraction of volcanic environments to tourists, for
example the geysers and boiling mud pools of Iceland, provide many job
opportunities in the tourism industry. Other economic benefits of volcanic
areas includes the provision of a source of cheap geothermal energy (28of
Iceland's electricity comes from these sources). Finally, a lack of money can
explain why many poor people in LICs still live in volcanic prone areas as they
cannot afford to move.
Damage caused by earthquakes and volcanoes can be prevented by
adequate building design, planning and education. How true is this statement,
use examples in your answer (6 marks)
Advice:
The question asks about damage caused by BOTH earthquakes and
volcanoes - so you must make sure you address both in the answer.
How true is this statement? - you need to be able to give an opinion and back
it up using examples
The question ask for examples - therefore unless more than one example is
used you will lose marks.
Possible Answer:
Although it is not possible to ensure that earthquakes cause no damage, it is
certianly true that adequate building design, planning and education can be
used to significantly limit the damage caused by earthquakes (1). Techniques
include the use of rubber shock-absorbers between the foundations and the
building structure to absorb earth tremors (1), as well as computer controlled
counter-weights on roofs to reduce movement. The TransAmerica building in
SanFrancisco has been designed with a wide stable base and a steel frame,
enabling the building to sway with the movement (1). Automatic shut off
switches for electricity and gas can also help to prevent problems of fire
following an earthquake (1). Training and education of emergency services
and people in earthquake drills (e.g. Japan's 1st Sept disaster prevention day)
help people to prepare for the event of an earthquake.(1). Damage caused by
volcanoes is harder to prevent through building design but roofs with an
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angled design can encourage ash not to accumulate which would otherwise
cause the roof to collapse (1).
Other points you could have included:
Earthquakes - Strict planning regulations can ensure buildings in earthquake
prone areas are not built on unstable land (helping to prevent problems of
liquefaction e.g. San Francisco)
Volcanoes - lava flows in Mt Etna (Sicily) and Eldfell volcano (Iceland) have
been successfully divered - e.g. by use of water sprays and the use of
explosives.
Choose a volcanic eruption or earthquake you have studied. Explain the
causes of the volcanic eruption or earthquake. (6)
San Francisco is located on the San Andreas Fault Line which marks the
boundary between the North American and Pacific Plate (a conservative Plate
boundary). As the two plates move past each other, pressure builds up due to
friction. The earthquake occurred due to the sudden release of the built up
pressure. The epicentre of the earthquake was under a mountain known as
Loma Prieta, 10 miles NE of the city of Santa Cruz. The 1989 earthquake
(measuring 6.9 on the richter scale) was the largest earthquake to have hit
California since the 8.2 earthquake of 1906.
Choose a volcanic eruption or earthquake you have studied. Explain the
effects of the volcanic eruption or earthquake. (6)
Your chosen case study must be CLEARLY LOCATED (place specific detail
is important - e.g. names of plates and clearly defined geographical location).
You also need to ensure that you explain the cause of the earthquake (i.e. talk
about what is happening at, in the case of Haiti, a conservative / transform
boundary.
Higher Tier
Level 1 (1-2) - a basic answer with descriptive statements
Level 2 (3-4) - a clear answer with level 2 being reached by there being an
explanation or a specific point. The top of the leevel requires a range of
specific points or a number of explanations or a specific point and an
explanation.
Level 3 (5-6) - an explicit answer with a range of specific and explained
points.
The questions clearly asks for EFFECTS (so you will not be credited for
talking about the cause in this question) and it is also asks for effects on
PEOPLE AND the ENVIRONMENT - you must mention both to ensure access
to full marks.
You MUST also ensure that there is clear PLACE SPECIFIC DETAIL - or you
will not be able to access the highest marks.
Chosen case study: The Loma Prieta (San Francisco) 1989 earthquake
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The effects of the 6.9 earthquake included 67 Deaths, 6,000 Homes damaged
/ destroyed and 2000 people made homeless. As San Francisco is in a HIC
the damage was minimized due to building regulations and seismically
designed buildings. The areas were the infrastructure was worse effected was
The Marina / Bay District Here the buildings were wooden and not securely
attached to their foundations. The area was also located on an old landfill site,
which was created following the devastation caused by the 1906 earthquake.
As a result of the weak sub-surface sediments, when the ground shook in the
1989 earthquake, the process of liquefaction occurred.
This is where as the ground lost its sheer strength and acted more like a liquid
as water moved up through the sediments resulting in reduced strength and
causing buildings to collapse due to lack of support. Many of the older (50-100
year old) buildings which were not designed to withstand earthquakes were
most severely damaged. Low-rise building were also worse affected than
taller buildings which swayed with the quake/ ground motions. Additionally, a
number of roadways were damaged during the earthquake, including the
collapse of the upper tier of the double-decker Nimitz Highway (Interstate 80)
onto the lower deck, killing and trapping motorists in their cars. The collapse
was caused partly by soil failure and also the unsuitable design of the
supporting piers. A section of the Bay Bridge also collapsed killing motorists.
There was massive economic costs ($4.4 billion) and damage to infrastructure
- electricity / gas and water mains cut
Or......
Montserrat was devastated by pyroclastic flows. The small population of the
island (11,000 people) was evacuated in 1995 to the north of Montserrat as
well as to neighbouring islands and the UK. Despite the evacuations, 19
people were killed by the eruptions as a small group of people chose to stay
behind to watch over their crops. Volcanic eruptions and lahars have
destroyed large areas of Montserrat. The capital, Plymouth, has been covered
in layers of ash and mud. Many homes and buildings were destroyed,
including the only hospital, the airport and many roads. In the longer term
there have been some positve effects new roads and a new airport were built,
Services in the north of the island were expanded. The presence of the
volcano resulted in a growth in tourism.
Explain how the effects of volcanic eruptions are reduced through prediction
and prevention. Use examples in your answer.
Explain the methods used before and after a natural disaster to limit its effects
(6 marks)
Methods that can be used Before:
Emergency drills and evacuation procedures set up and practiced (e.g. Japan
1st - emergency drill day)
Fully train emergency teams and have proper rescue equipment available
with emergency people trained in use
Earthquake proof buildings and major infrastructure (e.g. bridges - Golden
Gate, San Francisco and Transamerica Building, San Francisco)
Seismic monitoring
Methods that can be used after the disaster:
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A well co-ordinated relief effort (but rely's on prior planning)
LICs need to welcome help from HIC's and charites as soon as possible
Government needs to co-ordinate a response plan (following
Kobeearthquake, government were slow to respond - and effect were worse
than could have been)
Outline 3 techniques we can use for monitoring volcanoes (6 marks)
1. Earthquake activity often increases before an eruption due to rising magma
forcing its way to the surface (1). Seismometers can be used to measure
increasing earthquake activity in volcanic areas and therefore help predict an
eruption (1).
2. As magma rises to the surface, it often causes changes in the shape of a
volcano (1). Tiltmeters or GPS technology can be used to indicate and
measure the growth of a bulge on the sides of a volcano (such as that at Mt St
Helens - 1980) (1).
3. Rising magma is accompanied by an increase in the gas sulphur dioxide
(1). Gas sampling can be used to monitor levels of sulphur dioxide, a sudden
increase in which may indicate the increased likelihood of a volcanic eruption
(1).
Could also talk about:
(i) Geothermal Monitoring - monitoring increasing heat indicating rising
magma
(ii) Patterns of past eruptions - can help look at regularity in eruptions to help
with prediction.
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RESERVOIR BUILDING: Adds a new store to the hydrological
cycle. But....brings
PROBLEMS: 
Loss of land – drowns villages, farmland
Disease – stagnant water mosquitoes 
Vegetation drowned releases methane = greenhouse gas
BENEFITS:
Water supply
Can prevent flooding- e.g. Three Gorges Dam
Recreation – fishing, sailing, walking, wildlife
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Conflict over a water transfer scheme: Colorado
River Basin,
USA
The Colorado River is located in South-West USA and North-West
Mexico. It is over 2,300km and has its source in the Rocky Mountains
and its mouth in the Gulf of California. Its drainage basin covers an area
of 640,000km2. The Colorado River and its tributaries pass through the
US states of; Wyoming, Nevada, Utah, California, Arizona, Colorado
and New Mexico. The climate across the river basin is very varied, in
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the Rockies temperatures can fall to -50 degrees Celsius an experience
precipitation in excess of 1000mm, whereas some areas in the Mojave
Desert can experience temperatures of nearly 50 degrees Celsius and
precipitation as low as 15mm. About 12.7 million people live within the
drainage basin of the Colorado River, although some people outside the
drainage basin (especially in California) use water from the Colorado
River. In total it is estimated that about 40 million rely on the river for
domestic, agricultural, industrial and energy needs.
To cope with the massive demand the Colorado River has become one
of the most managed river's in the world. The river has over 29 major
dams built along its and hundreds of miles of artificial canals. The
Hoover Dam was one of the first major dams built along the river (and
certainly the most famous), it was completed in 1936 and created Lake
Mead - this is still the US's largest artificial lake.
OVERABSTRACTION: Too much water is being taken from the
river/lake/water source.
Dramatic decrease in river flow
Tributaries dried up
Ecosystem damaged
Droughts and increased demand from more homes increased use of
groundwater supplies falling water table so the store of water is not used
sustainably.
Most water companies now have strict policies CAMS (Catchment
Abstraction Management Strategies) for managing water levels.
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Examples of questions
How does greater wealth lead to increasing water consumption (4 marks)
he focus here needs to be on how the increase in wealth leads to the increase
in water consumption - all the ideas are simillar you are not explaining why
HICs use more water than LICs you are looking at why people tend to use
more water if they have more money.
Possible Answer:
Wealth leads to an increase in water consumption as there is a greater
demand for water in the activities that people in HICs are involved in. As
wealth increases and there is more disposable income, people make more
use of labour-saving devices, such as washing machines and dishwashers
which use large amount of water. There is also greater water use for luxuries
such as washing cars, swimming pools etc. Increasingly HICs have become
“showering societies” with greater personal hygiene and more water use.
Finally, greater wealth in a society tend to lead to greater industry, which uses
high amounts of water, for example for cooling machinery.
Compare and contrast the use of water in HICs and LICs ( 4 marks)
The command word compare requires you to state any similarities between
HICs and LICs. Contrast requires you to state differences.
Possible Answer:
HIC’s have a much greater water consumption than LIC’s (up to 3x as much
per year). The USA average water use per person per day is 600 litres,
compared to only 25 litres per person per day in the Sahara. In LICs, much of
the water (91 is used for agriculture (this is only 39in HICs), whereas in HICs,
most water (47 is used in industry. Overall, HICs use much greater water for
domestic uses (14of water use) than LICs.
Describe and suggest explanations for the global pattern of water surplus and
deficit (5 marks)
Advice:
If describing a pattern you should ensure (i) you answer is specific by naming
countries / continents and if you are asked for data - you must include it or
you will lose marks. Even if data is not requested, still try and include it as you
will be given credit.
This question is a Double Command - i.e. here you need to describe the
pattern - i.e. which places have a water surplus / deficit and then explain
(suggest reasons) for this pattern (i.e. make the link to temperature and
rainfall).
Possible Answer:
We mainly find areas of water surplus in the northern hemisphere, particularly
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in more temperate places like Northern America and Northern Europe. In
other areas, such as the Middle East and North Africa, there may be found a
water deficit due to physical scarcity where demand exceeds supply. These
variations can be accounted for by variations in rainfall distribution, as well as
differences in temperature. North Africa and the Middle East are very arid,
with low rainfall and high rates of evapotranspiration due to high
temperatures. In some places, such as South America, there is an economic
scarcity of water, where people cannot afford to access water (e.g. Brazil)
even though the rainfalls regularly each day and throughout the year. This is
because of the very high evaporation rates.
Explain why water borne diseases are a major problem associated with water
supplies in LICs (4 marks)
Possible Answer:
In LICs, there is real lack of access to safe water, for example in Eritrea only
7of 100 people have access to safe water. As a result, over a million children
die every year due to disease caused by unclean water. Unclean drinking
water can contain bacteria and parasites which lead to serious diseases such
as dysentery, typhoid and Bilharzia which claim many lives (15 people each
week die of typhoid in Sierra Leone). Another disease, Trachoma, is caused
by parasites in contaminated water which can lead to blindness. In LICs,
many (2.6 billion) do not have access to proper sanitation and in these areas
bacteria from faeces may get into drinking water, causing serious outbreaks of
cholera.
What is meant by appropriate technology? Why is it important in ensuring the
success of water management in LICs? (Give examples) - 6 marks
Advice
In your answer, the examiner will be looking for 3 things to be present for the
full marks:
(i) A definition
(ii) Justification of why this is important in successful water management
(iii) examples - Remember - when asked to give examples - if you do not
do so you will lose marks!
Possible Answer:
Appropriate technology involves using equipment that the local community
can use relatively easily and is essential to the success of water
management in LICs. This is because lack of money means that expensive
high technology solutions are not an option and such techniques are difficult
to sustain in poor communities who don't have the knowledge to fix problems.
Appropriate technology techniques include the use of hand-dug wells, as well
as tubewells and boreholes. Hand Dug wells are the most common method of
getting water, however tubewells are better. They are cheap to build, safe to
construct and reach greater depths, resulting in less water wastage due to
evaporation. Handpumps can then be used to draw up water. In areas where
rainfall totals are quite high, gutters from cleaned roofs are used to collect
water which is stored in tanks for later use. This simple and cheap process is
known as rainwater harvesting. Gravity-fed schemes have also been used in
LICs, where water from water sources higher up are piped down to
communities using the force of gravity. In some parts of India, there is an
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emphasis on recycling water, including the treatment of sewage to make it
drinkable.
Using examples, describe how water usage is being managed in HICs in the
following areas (6 marks)
(i)
Domestic Water Use
Various attempts have been made in HICs to manage water usage in homes,
including all new homes being fitted with water metres enabling people to be
charged for the water they use, encouraging more efficient water use. Water
conservation in toilets has been encouraged, through the use of dual flushes
(saving 50of the water of a normal flush) and the use of “Hippo” bags in the
cistern, displacing water and saving 1 litre for every flush. Fixing broken taps
and pipes and the use of hosepipe bans are other management strategies
used.
(ii)
Agricultural Water Use
In HICs, agricultural water management revolves around minimises losses
due to evaporation or runoff. Overhead irrigation sprinklers, provide a more
equal distribution of water and is more efficient than flood irrigation. Drip
irrigation is also used to deliver water straight to plants and minimise water
loss. Other techniques include loosening soils to encourage infiltration &
reduce runoff. Irrigation at night time also reduces loss by evaporation
Explain why water transfer can cause conflict between countres. Use a
named example (6 marks)
Water transfer can cause conflicts between countries, for example that along
the Colorado River in the USA which flows from the Rocky mountains,
2300km into the Gulf of California. Along the river there is great conflict
between users, those who live in the upper part use water for irrigation and
cattle ranching, lower down significant population increase and the growth of
new towns like Las Vegas have seen a huge demand for water and HEP.
There have been various attempts to manage the river through the use of
dams. However there is no overall control of the river from the source to the
Gulf of Mexico. There is conflict between the USA and Mexico as much of the
water has been taken out of the river before it reaches the Mexican border.
The Mexican government have had to build a desalinations plant at huge cost.
There has also been a significant impact on wildlife with habitats of egrets and
fish such as the totoaba lost.
Choose a water transfer scheme that you have studied. Explain the dispute
caused by the water transfer scheme (6 marks)
The Colorado is a very good example of a water transfer scheme that has
caused disputes. The Colorado River in the USA is a major river which flows
from the Rocky mountains, 2300km into the Gulf of California. Since the
building of the Hoover Dam in 1936 the use of water from the river has been
controversial. Today there are 11 major dams and reservoirs which are used
for HEP, water supply and recreation. There are also huge water transfer
schemes such as the All American Canal and the Central Arizona Project
which provide water for large cities such as Las Vegas in Nevada & Los
Angeles in California as well as surrounding farm land . The disputes have
been caused because the native American Indians claim ownership or water
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rights and these have been largely ignored. Cattle ranchers in the upper
basin and cereal/ fruit growers in the lower basin need irrigation water but
demand is increasingly exceeding supply and costs are high. This also
causes disputes with the Mexicans as the Colorado no longer flows though
Mexico into the Gulf of California and the water they do get is too salty to use
having already been used for irrigation by American farmers. Mexico is a LIC
and is now increasingly dependent on expensive desalinated water from
places like Yuma. Such water transfer schemes also cause disputes with
environmentalists who are concerned about the loss of wetland habitat
especially in the delta area resulting in the decline in egrets, totoba fish,
marine grasses and tortoise.
Choose a water management scheme which you have studied. Explain the
effects of the scheme (6 marks)
MARK SCHEME:
Foundation Tier:
Level 1 (1-2) - simple answer - little description - not related to any specific
example
Level 2 (3-4) - basic answer - descriptive points or a specific point, or a weak
explanation. Must be two of these to reach level 4.
Level 3 (5-6) - clear answer - must be clear explanation or a specific point top level requires range of specific points or a number of explanations.
Higher Tier:
Level 1 (1-2) - basic answer - with descriptive statements only.
Level 2 (3-4) - clear answer - must be explanation / specific points to reach
L2. Top L2 (4 marks) - requires range of specific points / number of
explanations or specific point and an explanation.
Level 3 (5-6) - explicit answer - range of specific / explained points (well
exemplified.
Possible Answer:
The Three Gorges Dam project in China was established to control the
flooding of the Yangtze river with construction starting in 1998. The scheme
has brought both positive and negative effects. On the one hand the project
has successfully protected 100 million people downstream from flood danger.
It has also led to significant economic growth. As well as improved navigation,
enabling large ships to navigate all year round, tourism now generates around
£10 million a year and employs many local people. Economic development
has been further supported by the HEP produced in the dams power stations.
However, the construction of the dam forced 1.3 million to move and 4 cities
and many other settlements were submerged. Farmers downstream of the
dam no longer receive the fertile silt for their fields which is now trapped in the
upper Yangtze by the dam. There have also been concerns over the dams
impact on the river and its wildlife, with sturgeon and Siberian cranes under
risk of extinction. As can be seen, the scheme remains a controversial one.
For a water management scheme that you have studied, explain why the
scheme was necessary (4 marks)
The Three Gorges Dam project in China began in 1998 and involved the
creation of a 660km long reservoir holding back the flood waters of the
Yangtze river, which flows 600km from Tibet into the East China Sea. The
scheme was necessary as the river is prone to flooding and the frequency and
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intensity of flooding has increased in recent years with 3000 killed in the 1998
floods. The drainage basin is large and seasonally intense monsoon rains hit
at a time coinciding with rising temperatures and rapid snow melt, increasing
the flood risk. Urbanisation on the floodplain and extensive deforestation in
the upper basin have also increased runoff and flooding and the dam was
required to provide storage of flood waters and protect millions of people. For
China to modernise and develop economically it needs to be able to rely on
the Yantze for all the year round navigation as well as being assured that
major cities such as Shanghai are protected from flooding.
Many water management schemes have been built around the world.
Evaluate the success of ONE water management scheme that you have
studied (6 marks)
MARK SCHEME:
Foundation Tier:
Level 1 (1-2) - simple answer - little description - not related to any specific
example
Level 2 (3-4) - basic answer - descriptive points or a specific point, or a weak
explanation. Must be two of these to reach level 4.
Level 3 (5-6) - clear answer - must be clear explanation or a specific point top level requires range of specific points or a number of explanations.
Higher Tier:
Level 1 (1-2) - basic answer - with descriptive statements only.
Level 2 (3-4) - clear answer - must be explanation / specific points to reach
L2. Top L2 (4 marks) - requires range of specific points / number of
explanations or specific point and an explanation.
Level 3 (5-6) - explicit answer - range of specific / explained points (well
exemplified.
Possible Answer:
The Three Gorges Dam project in China began in 1998 with the largest HEP
dam in the world being constructed. On the one hand the scheme has brought
many benefits. One of the key reasons for the scheme was the problem of
increased frequency and intensity of floods along the Yangtze, the reservoir
will now store flood water from even a 100 year flood and 100 million people
down river have been protected from flood danger. It has become an
economic growth corridor and new settlements created as part of it have
modern facilities and transport links. This economic development will be
further supported by the HEP produced by 2 power stations which in itself is a
sustainable energy source. Significant income has also been generated
through tourism, with an income of £10 million in 2007. Despite these many
successes, there have been a number of disadvantages, including the
relocation of over 1.3 million people and the loss of many settlements. Ancient
temples, sacred sites and farmland were also lost. Farmers downstream no
longer receive much fertile silt carried by the Yangtze as it is trapped by the
dam. The cost of the project was massive and exceeded the budget of £15
billion. Therefore despite its benefits, the scheme remains controversial.
There is great uncertainty about the effects of the dam on the wildlife and
doubt over economic benefits.
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Resource exploitation can cause problems to water supplies in LICs. Outline
the problems caused (4 marks)
Possible Answer:
Exploitation of resources can lead to serious pollution of water supplies in
LICs. For example a Coca Cola plant located in Kerala (India), was forced to
close in 2004; as well as serious depleting groundwater levels (9 litres
required to produce 1 litre of coke!), there were also concerns over severe
pollution of water supplies due to contamination by heavy metals such as lead
and cadmium from factory waste. In Peru, exploitation of rainforest areas due
to drilling for oil by the Occidental Petroleum Company, has seen the release
of high levels of heavy metals and hydrocarbons into the water supply,
causing serious health problems and killing wildlife.
If this question was worth more marks, or as an alternative to one of the
above problems you could also have mentioned:
General increases in deforestation due to increased demand for land for cattle
ranching, has also polluted water supplies in areas such as Costa Rica due to
rivers being polluted with pesticides and fertilisers.
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