Download Restless Earth Revision Paper 1

Restless Earth Revision
Paper 1 – Physical Geography
Question 1
What do you need to know?
1. The Earth’s crust is unstable, especially at plate
margins. Unique landforms occur at plate margins.
(01:17)
2. People use these landforms as a resource and
adapt to the conditions within them. (11:33)
3. Volcanoes are hazards resulting from tectonic
activity. Their primary and secondary effects are
positive as well as negative.
(18:19)
4. Supervolcanoes are on a much bigger scale than
other volcanoes and an eruption would have global
consequences.
(26:59)
What do you need to know?
5. Earthquakes occur at constructive, destructive
and conservative plate margins.
(31:09)
6. The effects of earthquakes and responses to
them differ due to contrasts in levels of wealth.
(36:56)
7. Tsunamis are a specific secondary effect and can
have devastating effects in coastal areas.
(45:25)
1. The Earth’s crust is unstable,
especially at plate margins. Unique
landforms occur at plate margins.
Earth Structure
Earth Structure
Convection Currents
Plates
Volcanoes and Earthquakes
Types of Crust
Types of Crust
Oceanic
Continental
Newer – most less than 200
million years old
Older – most over 1500 million
years old
Denser
Less dense
Can sink
Cannot sink
Can be renewed and destroyed
Cannot be renewed or destroyed
Plate Margins
Name
Constructive
Destructive
Conservative
Movement
Apart and spreading
Together and destroying
Sliding past
Effects
Creates new land by
magma rising
Destroys crust through
heat and friction
Nothing created or
destroyed
Land changes
Ridge of new crust
No major changes
Activity
Shield volcano and
earthquakes
Ocean trench and fold
mountains
Composite volcano and
earthquakes
Earthquakes only
Destructive Plate Margin
What happens?
A continental plate and an oceanic plate
are moving towards each other.
The oceanic plate is denser (heavier) so,
it is forced underneath the continental
plate. This is called subduction.
The point at which this happens is called
the subduction zone. The oceanic plate
melts to form magma.
Creating a volcano…
The melted oceanic plate rises up through cracks in the continental crust to form
a volcano.
Constructive Plate Margin
What happens?
The oceanic plates move apart.
As the plates move apart (very
slowly), magma rises from the mantle.
The magma erupts to the surface of the
Earth.
Creating a volcano…
When the magma reaches the surface, it cools and solidifies to form new oceanic
crust. Eventually the new rock builds up to form a volcano.
Conservative Plate Margin
What happens?
Here plates slide past each other.
The plates eventually become stuck
and tension builds up.
Eventually this tension and friction
is released as they slip past each
other in a sudden movement.
Creating an earthquake
The shockwaves created from this movement produce an earthquake.
Ocean Trench
Where there is a destructive plate margin
and oceanic crust is going below continental
crust, an ocean trench occurs.
.
Ocean Trench
This is a deep part
of the ocean found
where the oceanic
plate is being sub
ducted under the
continental plate.
Fold Mountains
Where two
continental
plates collide
or when a
continental
plate is pushed
up by the
subduction
of oceanic
plate you find
fold mountains.
Distribution
Formation
Rivers erode material from the
land surface and transport it to
the sea depositing it at the
bottom of the sea.
Layers build up over time to form
sedimentary rock. At a
destructive plate boundary two
plates move towards each other.
As the plates move towards each
other the sedimentary rock
crumple creating fold mountains
with synclines and anticlines.
2. People use these landforms as a
resource and adapt to the conditions
within them.
Uses of Fold Mountains
Alps
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The ALPS are located
in Central Europe and
cover Austria, Italy,
Switzerland, Germany
and France.
The Alps consist of
many high mountains
such as Mt. Blanc, the
Matterhorn and Eiger.
This is also where
Europe's great rivers
begin such as the
Rhine and Danube.
Around 12 million
people live there.
Farming
The valley floor is ideal for farming and the
main type is usually is Dairy Farming
although vineyards can be found in warmer
areas. It is ideal here because:
* The land is flatter
* The soils are deeper and more fertile
* There are better communications
Mountain farming takes up 13% of the entire
country with around 43,000 Alpine farmers
in Switzerland.
Tourism
• 100 million people visit the Alps every
year.
• 70% of Tourists visit in the winter
• 30% of people visit in the summer.
• Entirely new villages have been built
to cater for the vast quantity of
tourists (e.g. Tignes in France)
• Ski Runs, Ski Lifts, Cable Cars, Holiday
Chalets and Restaurants pepper the
landscape.
Forestry
Many trees wold not be able to grow in
the harsh conditions and on the steep
slopes, to combat this Scots pine is
planted all over the Alps because its more
resilient.
Forestry employs over 90,000 people in
Switzerland with 31% of Switzerland
covered in Alpine forest.
Hydro-electric Power
Hydroelectric power is generated by water
moving through a dam to turn a turbine; creating
electricity. The narrow valleys are perfect for
building a dam to generate hydroelectric power.
The highest concentration of hydroelectric power
stations is in the Berne region of Switzerland.
In total, 60% of Switzerland's electricity comes
from hydroelectric power stations in the Alps.
The Grande Dixence Dam in Switzerland powers
four different hydroelectric power stations.
Adaptations
Changes people make to ensure they are
able to cope with the conditions they live
in.
Steep Relief
• Many farms keep goats because they're
well adapted to live on steep mountains and
provide meat and milk.
• The steep sides of valleys is perfect to
build a dam to create hydroelectric power
plants.
• Some farms create
steps on steep slopes
so they are able to
grow crops, this is
called terracing.
Poor Soil
• Animals are grazed in the upper-most
areas as the soil is thin and un-fertile,
which means crops can't be grown very
well.
• Low lying slopes are more fertile so only
theses areas
are used to grow
crops, such as
vineyards.
Limited Communications
• It is difficult to get around due to all the steep slopes
this means that roads are only built over lower sections
between mountains, but these can be blocked by snow in
winter.
• As the countries are rich problems
like communication and transport
have been overcome. Modern road
tunnels e.g. Mont Blanc, St Bernard
have replaced old routes over high
passes. Many electrified railways link
the Alps to cities; rail tunnels
under the Alps include the
Brenner and St Bernard.
• Cable cars and ski lifts link
the valley floor to high level
benches and ski slopes above
them.
Natural Hazards
Avalanches and rockslides are two hazards that affect people in fold
mountains.
There are three ways that these can be
prevented.
• Explosions
Avalanches can be started deliberately in
order to prevent the snow building up. This is
one of the most important ways of preventing
avalanches.
• Snow fences and barriers
These can be used to divert and break up the path
of the avalanche.
• Reforestation
Trees can be planted, increasing stability of the slope and helping to
reduce the damage further down the valley.
3. Volcanoes are hazards resulting from
tectonic activity. Their primary and
secondary effects are positive as
well as negative.
Types of Volcano
Composite Volcano
• Composite volcanoes are made up of alternating layers of lava and ash
(other volcanoes just consist of lava).
• They are usually found at destructive boundaries.
• The eruptions from these volcanoes may be a pyroclastic flow rather
than a lava flow. A pyroclastic flow is a mixture of hot steam, ash, rock
and dust.
• A pyroclastic flow can roll down the sides of a volcano at very high
speeds and with temperatures of over 400°C.
Shield Volcano
•
•
•
•
Shield volcanoes are usually found at constructive.
They are low, with gently sloping sides.
They are formed by eruptions of thin, runny lava.
Eruptions tend to be frequent but relatively gentle.
Distribution
Montserrat
Montserrat is a tiny island in
the Caribbean measuring only
12 km N-S and 8 km E-W
(100 km2)
Until 1997, very much an
‘island paradise’ (and some
parts still are) with an
economy based on farming,
fishing and tourism.
Relatively poor with average household
income of around £2,800 a year.
Montserrat
Mt Soufriere
Hills Volcano
Capital City
Plymouth
Do Not
Enter
Video
YouTube
Montserrat
GCSE
Geography
Case Study
Before/After
Before/After
Key words
Primary Effects: the immediate effects
of the eruption caused directly by the
eruption.
Secondary Effects: the after effects
that occur as an indirect effect of the
eruption on a longer timescale.
Primary Effects
• 19 people died after going into the
exclusion zone.
• Plymouth - the capital city was buried
under 12m of ash and mud.
• Bramble airport and the port in
Plymouth were destroyed.
• Farmland was destroyed
• Forest fires caused by pyroclastic flows
• Many schools and hospitals were
destroyed
Secondary Effects
• Fires destroyed many buildings.
• Tourists stayed away from the island
and the economy was disrupted.
• 8,000 of the island 12,000 inhabitants
left.
• Volcanic ash will improve soil fertility
• Some tourists come because of the
eruption.
Immediate Responses
• People were evacuated from the south
of the island to the north.
• Shelters were built for the evacuees.
• The UK provided £17million of
emergency aid.
Long Term Responses
• A risk assessment was done to help
islanders understand which areas are at
risk and reduce problems for the future
– creating an exclusion zone.
• £41 million was given in aid by the
British Government.
• The MVO (Montserrat Volcano
Observatory) was set up to study the
volcano and provide warnings for the
future
Prediction of Eruptions
•
•
•
•
Earthquakes
Tiltmeters
Digital Cameras
Gases Emitted
4. Supervolcanoes are on a much bigger
scale than other volcanoes and an
eruption would have global
consequences.
Formation
Yellowstone
Yellowstone National Park is located in
the states of Wyoming, Montana and
Idaho in the USA.
Underneath Yellowstone
National Park is one of
the worlds largest
supervolcanoes.
Possible Effects
Yellowstone (87,000 predicted deaths)
Ash rise 40-50km into the atmosphere.
10,000 km of land destroyed.
Flights suspended.
Farmland destroyed.
UK would see the ash cloud 5 days later.
Buildings collapse under the ash.
40% of population face starvation as crops
fail.
• Some parts of Europe would see snow fall.
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Differences
Shape
Supervolcanoes are generally flat
(caldera) whereas volcanoes are steep
sided mountains with a crater.
Scale
Supervolcano would be on a larger scale
and much more violent with global effects
with thousands of tonnes more material
emitted than a volcano.
5. Earthquakes occur at constructive,
destructive and conservative plate
margins.
Distribution
Features
Formation
• Two plates at a plate margin cannot move
past each other easily.
• The plates become locked together.
• Friction causes pressure to build up.
• Suddenly, the pressure is released and the
plates jolt into a new position.
• This causes seismic waves.
• The vibrations they cause are an
earthquake.
Measuring
There are two different scales used to
measure earthquakes
Richter Scale
Mercalli Scale
This measures the
MAGNITUDE of an
earthquake.
This measures the
INTENSITY of an
earthquake
This means how much
energy is released.
This means the effects
of an earthquake
Richter Scale
Mercalli Scale
Prediction
We can try to predict
earthquakes, but only
on rare occasions is this
successful. The odd
behaviour of animals
and the analysis of
foreshocks led to the
evacuation of Haicheng
in China in 1975,
probably saving
150,000 lives.
Protection and Preparation
Video
YouTube
Millions To
Participate In
Thursday's
'Great Shake
Out'
6. The effects of earthquakes and
responses to them differ due to
contrasts in levels of wealth.
Rich – Kobe Japan
7.2 on the Richter
scale.
The epicentre
was 12 miles from
Kobe.
Video
YouTube
Great Quake
Kobe
Effects
• 6434 People died
• 340,000 people affected by the quake and 300,000
of those were made homeless
• 2 million homes were without electricity and 1
million without water for 10 days
• The great Hanshin Expressway
collapsed.
• Fires spread and were impossible
to extinguish because of
blocked roads and broken
water pipes.
• The quake caused $220 billion in
damages.
.
Immediate Responses
• Japanese government evacuated people
to temporary shelters
• Fire and emergency services searched
for survivors
• Hospitals treated the injured
• Motorola maintained phone connections
free of charge
• Bulldozers brought in to clear fallen
buildings
Long Term Responses
• Most rail connections repaired within a
month
• Port back in operation within a year
• Roads repaired within 6 months
• New buildings built to modern ‘earthquakeproof’ specifications (as older buildings
had collapsed)
• High rise buildings have steel frames
• Japanese now practice an earthquake drill
every year
Poor - Haiti
7.0 on the Richter
scale.
The epicentre
was 15 miles from
the nation’s capital,
city Port au Prince.
Video
YouTube
The week in
Haiti
Effects
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230,000 dead.
Over 1 million homeless.
Estimated that 150,000
residences and 30,000 commercial
buildings had collapsed or were
severely damaged.
The presidential palace was
destroyed.
5,000 schools were damaged or
destroyed.
Roads were also very badly damaged
and hindered aid efforts.
1 in 5 jobs lost as a result of the
earthquake.
Water became contaminated and
7,000 died from cholera related to
dirty drinking water.
Sewage and other substances
leaked into the sea killing wildlife.
$11.5billion worth of damage.
Short Term Responses
• Individuals tried to recover their belongings.
• Search and Rescue from other countries
• The actual aid effort was almost non-existent
from within Haïti as its institutions had been
destroyed or did not have the resources to
cope.
• Relied on the USA
and Dominican Republic
to supple food, water,
medical supplies and
shelters.
• UK Disasters Emergency
Committee raised over
£100million
Long Term Responses
• The EU gave $330 million and the World Bank
waived the countries debt repayments for 5
years.
• 6 months after the quake, 98% of the rubble
remained uncleared; some still blocking vital
access roads.
• Between 23 major charities, $1.1 billion had
been collected for Haïti for relief efforts.
• ¾ of damaged buildings were inspected or
repaired.
• 200,000 people received cash or food for
public work like clearing the rubble.
Why did Haiti Suffer?
• Is incredibly poor – most people survived on less
than $2 a day.
• 80% of people lived in poorly constructed buildings
– concrete that easily crumbled with no building
regulations.
• The earthquake was close to the city.
• Infrastructure such as the port and airport made it
hard to bring in supplies.
• A lack of doctors and medical facilities meant many
died from easily treatable injuries or disease.
• An unstable government meant that there was a
lack of coordination in rescue and recovery efforts.
7. Tsunamis are a specific secondary
effect and can have devastating
effects in coastal areas.
Formation
Japan 2011
Video
YouTube
BBC News
Panorama
Documentary
Japan
Tsunami
Cause
The earthquake occurred at a shallow
depth of just 20 miles below the surface
of the Pacific Ocean. This, combined with
the magnitude of 9.0 caused a tsunami.
Effects
• More than 20,000 people officially dead or missing, with many
more unaccounted for, including 9,500 people in one town.
• The port of Sendai was totally
destroyed.
• Radiation leaks from the damaged
Fukushima nuclear plant after an
explosion blows off the roof,
raising fears of a meltdown at
the nuclear power station.
• 500km2 of land was submerged
by waters and debris.
• Some 215,000 people living in
government shelters.
• Six million homes without power,
a million with no water.
• Experts say the total insured
loss could be up to $15bn.
Responses
• 100,000 Japanese soldiers
were deployed in search
and rescue.
• Exclusion zone was set up
around the Fukushima
nuclear plant evacuating
people from the area.
• One year after the
tsunami all of the debris
had been removed from
the affected areas.
• Huge re-building and
reconstruction programme
was put under way.
• Tsunami walls have been
re-built to be higher than
the usual 12m.
Restless Earth Revision
Paper 1 – Physical Geography
Question 1