Transcript 4TH YEAR - HCC Restless EARTH

GCSE
PLATE TECTONICS
Year 11
Learning intention
The Earth’s crust is unstable:
• The tectonic plates may move together or move apart
• At plate boundaries earthquakes, volcanoes and fold mountains
occur.
• There are different types of volcano –composite or shield (basic
lava)
The structure of the Earth
Core
Three zones
•
1.
2.
3.
The Earth’s structure has 3 parts:
Core – at the centre
Mantle – a large mass of molten rock surrounding the core
Crust – the surface of the Earth. A thin layer ‘floating’ on the
mantle.
Crust
• Two types of crust
• Oceanic crust – denser, about 5km thick
• Continental crust – less dense (lighter), about 30km thick
Earth’s crust - not one continuous layer
• Crust made up of 7 large
tectonic plates and many
smaller ones.
• Crust is unstable. Plates move
according to rising currents
called convection currents
within the mantle.
• The plate movement has its
greatest impact where the
plates meet. The further from
these boundaries between
plates the more stable they
tend to be.
Convection currents
Tectonic Plates
Plate boundaries
Tensional plate boundaries
• Plates move apart eg. N. American and Eurasian plates
• Gap filled by rising magma from the mantle
• Rising magma forms shield volcanoes
• Most common under oceans so submarine volcanoes or volcanic
islands are formed.
• Plates buckle to form ridges. Eg Mid-Atlantic Ridge
Tensional (constructive)
plate boundary
Constructive plate margin
This is when 2 plates move apart, usually under oceans.
As the plates move away from each other, cracks and fractures form
between the plates where there is no solid crust.
Magma rises into the cracks and forces its way to the surface to form
volcanoes.
New land is formed as the plates gradually pull apart.
Example: Mid Atlantic Ridge – N. American and Eurasian plates.
A Destructive plate boundary
Destructive plate boundaries
Subduction boundary
Convection currents in the mantle cause the Plates to move
together.
If an oceanic plate (Nasca plate) meets a continental plate
(South American plate) then the oceanic plate sinks under. This
is called Subduction.
The reason the oceanic plate sinks is it is denser and the
continental crust is lighter.
The oceanic plate melts in the subduction zone where there is
great heat, friction and pressure. The destroyed plate forms
magma. The magma will rise to the surface to form a volcanoe.
Energy may be released as an earthquake.
The molten rock or magma may rise forming
composite volcanoes.
The lighter the crust at the surface may
crumple to form fold mountains.
Destructive plate margins
Collision boundary
If 2 continental plates meet they collide, they do not sink beneath
each other.
This type of boundary creates fold mountains.
Passive or conservative plate boundary
Conservative
plate
margins
At Conservative plate margins the plates slide past
each other.
They move in a similar (but not the same) direction, at
different angles and speeds.
When one plate moves faster than the other and in a
slightly different direction the plates can get stuck. A
build up of pressure will eventually cause them to be
released. This sudden release of pressure causes
Earthquakes.
At a Conservative plate margin, crust is neither
destroyed nor made.
Eg. Pacific Plate and N.American plate
(San Andreas Fault).
Passive plate boundaries
• Plates slide past each other at a passive plate boundary (Pacific
and N.American). An example of a passive plate boundary is the
San Andreas fault in California. Earthquakes occur along the
fault.
What Landforms are found at plate
boundaries?
How are fold mountains formed?
• Fold mountains form along plate boundaries as a result of great
Earth movements.
• The general theory is:
Two plates with landmasses on them move towards each other
The plates push layers of accumulated sediment in the sea into
folds between them
This becomes a fold mountain range. Most fold mountains continue
to grow as the plates constantly move
Examples: the Himalayas (Asia), Rockies (USA), Andes (South
America), Alps (Europe)
Good geography resource for plates etc
• http://www.wwnorton.com/college/geo/egeo/animations/ch2.htm
• Andes
• 7000 km long
• Longest fold mountains in the world
• Extend length of S.America
• 300km wide
• Andes in Argentina, Bolivia, Columbia, Peru,
Ecuador, Chile
• Tallest peak Aconcagua (Argentina) 6960 metres
high.
Major Fold Mountains of the world
Alps
Urals
Appalachian
Rockies
Andes
Himalayas
http://www.platetectonics.com/book/page_11.asp
Copy diagram of fold mountains into books
Fold Mountains
Geosyncline
Sea
Plates
Sediments
compressed
and folded into
Fold Mountains
Plates
Compression
Large depressions
called Geosynclines
form between plates.
Seas filled the
geosynclines.
Rivers flowing into the
geosynclines carried
sediments (sand and
silt) which built up on
the sea bed
Over millions of years,
the sediments were
compressed
(squeezed), by their
own weight, into
sedimentary rocks eg.
Sandstone, limestone.
How fold mountains are formed?
• Large depressions called geosynclines form between
plates.
• Seas filled the geosynclines and rivers flowing into them
carried sediments (sand and silt) which built up on the sea
bed.
• Over millions of years the sediments were compressed, by
their own weight, into sedimentary rocks, eg. Shells into
Limestone, sand into sandstone. These rocks form fold
mountains today.
• The tectonic plates moved toward each other forcing the
sediments to be pushed upwards. This forms the fold
mountains with a series of anticlines (upfolds) and
synclines (downfolds).
Fold mountains and Ocean Trenches
• Fold mountains are some of the highest places on the
planet.
• Mt Everest is 8,850m high.
• Ocean trenches form some of the deepest parts of the
world.
• Both ocean trenches and fold mountains form as 2 plates
move together. If both occur together they are a result
of Subduction. If only fold mountains occur then Collision
is taking place.
The Alps – a range of fold Mountains
Why are they there?
• The Alps lie along a compressional plate boundary where, for ten
million years, two plates pushed together.
• The rocks were folded upwards forming simple folds, overfolds and
nappes.
• The Alps are young fold mountains formed 30-40 million years ago.
What are the physical
features of the Alps?
• High mountains eg. Mont Blanc (4810m)
• Steep slopes
• Deep valleys eg. Lauterbrunnen
• Lakes, eg. Lake Como, Lake Garda
• Source area for rivers eg. The Rhine.
What are the human
activities in the Alps?
B Tourism
Tourists are attracted by:
• Winter resorts e. Chamonix, St Moritz
• Summer resorts eg. Lake Garda
• Winter sports eg. Skiing. Tobogganing
• Beautiful scenery and the Alpine climate
• Ease of access through good communications eg. Simplon pass,
Geneva airport
What are the human
activities in the Alps?
A Farming
• Mostly on the valley floor where it is flatter, more sheltered,
warmer, with deeper soils
• Traditional dairying
• Main crops are hay and cereals with some vines and fruit in warmer
areas
• Use upland pastures in summer
What are the human
activities in the Alps?
C HEP and Industry
• Industry needing large amounts of electricity eg. Sawmills,
smelters, locate near to HEP stations which generate cheap
electricity from the fast flowing streams
• Traditional industries include clock making, paper and furniture
What are the human
activities in the Alps?
D Forestry
• Conifers cover the slopes up to about 1800 metres. The wood is
used for fuel, building chalets and for paper-making.
Influence of Fold Mountains on human
activities
• They often act as climatic barriers. Regions on one side of a
mountain range may have an entirely different climate form that on
the region on the other side.
• They often receive heavy rain/snow which may give rise to
important rivers. These rivers may be used for irrigation or for
developing hydro-electric power (HEP).
• Some mountains and their plateaus may contain minerals.
• They may act as barriers to communications or they can make the
construction of communications 9 (roads etc) difficult.
• Some mountain ranges have valuable timber resources.
Problems of Fold Mountain areas
• Fold Mountains, like the Andes, tend to have low population
densities because:• The high altitude and steep slopes make it difficult to build houses
and communication links, and to locate industries. Roads and
railways need expensive tunnels and passes.
• There is little flat land for farming and the use of machinery is
difficult.
• The climate is also cold and wet with heavy snowfall and strong
winds, especially at high altitudes. The growing season is therefore
short and travel can be difficult, especially in the winter.
Avalanches and rock falls can block roads.
• However, the population density in the Andes is higher than in
many Fold Mountain areas because the soil in the valley floors is
reasonable fertile and the region is attractive to tourists from
nearby wealthy countries.
FOLD MOUNTAINS
CONTINENT
Andes
South America
Rockies
North America
Alps
Europe
Atlas
Africa
Himalayas
Asia
Pyrenees
Europe
Passive or conservative plate boundary
Volcanoes
Types of volcano
http://video.nationalgeographic.com/video/player/environment/environment-naturaldisasters/volcanoes/volcano-lava.html
http://news.bbc.co.uk/2/hi/science/nature/4972366.stm
http://videos.howstuffworks.com/discovery/7153-volcanoes-pyroclastic-flow-video.htm
Composite cone volcanoes usually form at
compressional plate boundaries (plates meeting)
Shield volcanoes usually form along tensional plate
boundaries (plates pulling apart)
MEDC – More Economically
developed country (Rich )
• Richer
• Able to afford Satellite and Early
warning systems to predict earthquakes
and volcanoes.
• Buildings are off a good standard to
cope with volcanoes (ash) and
Earthquakes (Earthquake proof) – use
hi-tech materials and do not fall down
easily.
• Better and quicker aid to help people
quickly after a natural hazard happens
(eg. Helicopters to rescue people, fire
brigade, ambulances, better hospitals,
army etc)
• Better roads, bridges, airports etc
(better infrastructure)
• More money and better professionals to
rebuild roads, bridges, buildings quickly
and to a high standard
LEDC – Less Economically
Developed Country (Poor)
• Poorer
• Can not afford Satellite and Early
warning systems to predict
earthquakes and volcanoes.
• Buildings off a poor standard made
out of mud, wood or corrugated iron
sheets – fall down easily.
• Aid and help slower to arrive for after
a natural hazard happens (eg. No
Helicopters to rescue people; poor
standard of fire brigade, ambulances,
hospitals, army etc)
• Poor roads, bridges, airports etc
(poor infrastructure)
• May be years before bridges, roads
and buildings are repaired (if at all).
• Draw a volcanoe and label parts of it
• Lahars – mudflows and landslides caused by melting ice due to
volcanic activity
• Pyroclastic flow – Flow of hot ash, steam and rock down the side of
a volcano after it erupts. It can travel at 300 miles per hour and
cook a person in a millisecond.
Volcanoes
• A volcano is a cone shaped hill or mountain of lava.
• Active volcanoes are ones which have erupted recently.
• Dormant volcanoes have not erupted in 2000 years but they could
still erupt.
• Extinct volcanoes are unlikely to ever erupt again.
Volcanoes
They are natural hazards – just like Tsunamis and Earthquakes.
Volcanoes are magma that has risen to the surface through cracks in the
earth’s crust. Each eruption adds a new layer to the volcanoe, seeing it
grow larger and larger.
Composite volcanoes occur at destructive plate margins. They are created
by thick lava that does not move much giving rise to a tall cone shape with
a narrow base. They give very violent eruptions eg. Mt St Helen’s, USA;
Vesuvius, Italy.
Shield volcanoes occur at constructive plate margins. They are created by
runny lava giving them a wide base, but they are not very tall as a result.
They erupt often but gently eg. Mauna Lau, Hawaii; Heimaey, Iceland.
Volcanoes occur at plate boundaries – where two plates meet.
Most of the world’s volcanoes are around the edges of the Pacific
Plate. We call this area the ‘Ring of Fire’.
Homework – Past Paper Questions
• Use the diagram showing the world’s volcanoes
• Describe the distribution of the world’s Volcanoes.(4 marks)
• How is the distribution of supervolcanoes different from that of
volcanoes? (2 marks)
• Explain why volcanoes are found at destructive plate boundaries. (3
marks)
• Describe the ways in which a supervolcano is different from a
volcano. (4 marks)
• Using case studies of volcanoes in rich and poor parts of the
world, compare and describe the immediate responses. (8 marks)
Describe the distribution of the world’s
Volcanoes.(4 marks)
• On plate margins
• Give examples – name some plate margins eg. Nazca and South
American
• At Destructive and Constructive plate margins
• None at Conservative
• A few in middle of plates
• Hotspots eg. Mauna Lau, Hawaii
• Supervolcanoes where?
Mark Scheme
How is the distribution of supervolcanoes
different from that of volcanoes?
1(a)(i) Any 2 ways
• E.g. volcanoes occur in linear clusters (1), while supervolcanoes are
much
• more scattered / occur individually (1); volcanoes occur on plate
• boundaries (1) while supervolcanoes occur some distance from
them
• e.g. in North America (1).
• Volcanoes occur at both constructive and destructive plate
boundaries (1)
• whilst supervolcanoes appear to be nearer to destructive only (1).
• 2 x 1 or 1 x (1 + 1).
• 2 marks
Explain why volcanoes are found at destructive
plate boundaries.
• 1(a)(ii) Oceanic and continental plates move towards each other (1);
• the denser oceanic crust goes below the lighter continental crust
(1);
• as it is pushed into the mantle, it is melted and destroyed (1);
• a pool of magma and an increase in pressure results (1);
• this is released by an eruption at the surface where the magma
escapes along a crack (1).
3 x 1 3 marks
Describe the ways in which a supervolcano is
different from a volcano.
• 1(a)(iii) May refer to shape / appearance, size of feature, scale of an
eruption,
• impact of an eruption.
• Shape – supervolcanoes are flat / surrounded by higher mountains in
contrast to the gentle / steep sided mountain / presence of a crater of a
volcano.
• Size – they are much bigger than a volcano, but less easy to see on the
• ground e.g. Yellowstone National park is essentially a supervolcano.
• Scale – supervolcano would be much more violent and dwarf eruptions
• such as Mt St Helens will have much wider effects – on a global scale;
willemit much more material – either ash or magma.
• Impact – will have devastating consequences within 200km – all life gone
and serious impact on continents unlike volcano where effects more
localised.
Level 1 (Basic) 1–2 marks
• Describes the features of either a volcano and/or supervolcano separately.
• Simple statements.
• Knowledge of basic information
• Simple understanding
• Few links; limited detail; uses a limited range of specialist terms
• Limited evidence of sentence structure. Frequent spelling, punctuation
and grammatical errors.
Level 2 (Clear) 3–4 marks
• Links statements.
• Develops points.
• Makes contrasts clear.
• Knowledge of accurate information
• Clear understanding
• Answers have some linkages; occasional detail/exemplar; uses some
specialist terms where appropriate
• Clear evidence of sentence structure. Some spelling, punctuation and
grammatical errors.
Composite cone volcanoes
Examples:
Mount Etna,
Vesuvius, Mount
St Helens
Characteristics:
• Steep sided symmetrical cone
shape
• High with narrow base
• Alternate layers of acid lava and
ash
• Lava may cool inside the vent –
the next eruption is very
explosive to remove the plug
• Subsidiary cones and vents
form
Shield (basic lava) volcanoes
• Examples: Mauna Loa and
Kilauea, both on the
Hawaiian islands
Characteristics:
• Gentle slopes and wide
base
• Frequent eruptions of
basic lava
• Lava flows more easily,
travels longer distances
before cooling
• Usually non-violent
Composite cone volcano
• These volcanoes are composed
(made up) of alternating layers
of lava and ash (other volcanoes
just consist of lava).
• 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
• These are usually found at
constructive boundaries.
• They are low, with gently
sloping sides.
• Shield volcanoes are
formed by eruptions of
thin, runny lava.
• Eruptions here tend to be
frequent but relatively
gentle.
Advantages of living near volcanoes
• There are rich soils derived from weathered ash and lava.
• There are hot springs for bathing and spa resorts have developed
around these
• e.g. Bath.
• Geothermal energy – Cheap electricity is generated by steam
derived from hot springs e.g. Iceland.
• Tourism – Hot water fountains or geysers, such as Old Faithful in
Yellowstone National Park in the USA, are major attractions for
tourists.
• Rocks and minerals – minerals are found in volcanic rocks e.g.
sulphur and borax which are used to make products such as
cement, glass, gunpowder and drugs. Metals such as iron,
copper, nickel and manganese occur in some volcanic regions.
Disadvantages of living near volcanoes
• When volcanoes erupt they lead to:• Loss of life.
• Loss of homes, animals and crops.
• Loss of wildlife, trees and plants.
• Toxic gas clouds which poison/suffocate all they drift over.
• Superheated clouds of gas and dust which engulf whole
communities.
• Avalanches, mudflows and flooding in an area.
• Case Study Mount St Helens
• Cause The Juan de Fuca Plate (oceanic crust) moves towards the North
America Plate (continental crust) and is forced downwards. The oceanic crust
is destroyed. The pressure causes friction and the melted rock is forced to rise
to the surface as a volcano.
• Sequence of events
• Spring 1980
Bulge developed on the north side of the mountain.
• May 1980
Earthquake caused the bulge to move outwards.
•
Landslides, mudflows and flood water affected the
surrounding area.
•
Blast wave from the main explosion killed everything within
25 km to the north.
•
Gas, ash and volcanic bombs are continually ejected.
•
Ash plume reached the east coast of the USA.
•
Ash eventually encircled the whole world.
• Consequences 61 deaths, most of them caused by poisonous gases.several
logging camps were destroyed.This killed all fish, including those in a
hatchery.Floodwater washed away roads and railway bridges.
• Telephone wires are cut.
• Roads and bridges are washed away.
• There is a danger of more eruptions.
• Sightseers block the roads.
• Areas are isolated.
Supervolcanoes
• Take down notes from notebook
• Definition of Caldera
• Explain and give notes on keywords
• Map of and draw Caldera as how supervolcanoe is formed
• Pictures and map of Yellow stone
• Differences between supervolcanoes and normal volcanoes
Case Studies
•
Need to know 3 things:
1. Causes – what made it happen
2. Effects – how it affected the people eg. Deaths,
damage
3. Responses – what people did in the aftermath,
repairs, shelters etc
Monitoring and predicting Volcanoes
Tiltmeters – can detect whether slope on volcanoe is
getting steeper (sign of eruption being near)
Global Positioning System – Uses satellites to detect
movement as small as 1 mm (more movement, more
chance of eruption)
Gases – Sulphur dioxide (smells of rotting eggs) being
given off, and dead animals found near volcanoe are
a sign of eruption being near
Digital cameras – comparing pictures you can see sides
of volcanoes swelling (sign of eruption near)
Satellites – using infra-red images can see heat. If
magma is near surface, sign of eruption being soon
Super volcanoes
Characteristics of Supervolcanoes
• -A much bigger scale (ordinary volcanoes much smaller)
• -Emit at least 1000km³ of material (ash, gas) (Ordinary volcanoes
emit much less eg Mount St. Helen's emitted 1km³
• -Have a large depression called a Caldera (Ordinary volcanoes have
a crater)
Effects of a Super volcanoe
Describe the ways in which a supervolcano is
different from a volcano.
• 1(a)(iii) May refer to shape / appearance, size of feature, scale of an
eruption,
• impact of an eruption.
• Shape – supervolcanoes are flat / surrounded by higher mountains in
contrast to the gentle / steep sided mountain / presence of a crater of a
volcano.
• Size – they are much bigger than a volcano, but less easy to see on the
ground e.g. Yellowstone National park is essentially a supervolcano.
• Scale – supervolcano would be much more violent and dwarf eruptions
such as Mt St Helens will have much wider effects – on a global scale; will
emit much more material – either ash or magma.
• Impact – will have devastating consequences within 200km – all life gone
and serious impact on continents unlike volcano where effects more
localised.
Location of Yellowstone in USA
Volcanoe
Shape
Supervolcanoe
Steep sided, cone shape. Has Supervolcanoes are flat, surrounded by
higher mountains.
a crater.
No crater.
Size
Much smaller.
Can be 2-5 km long
They are much bigger than a volcano,
but less easy to see on the
ground e.g. Yellowstone.
20 KM Long.
Scale
Local effects
Global effects. Much more ash Much
more violent eruptions. More
magma and ash given off.
Impact
All life gone within a few
miles. Can effect local
climate. May kill 100’s of
people
Devastating effects within 200km –
all life gone. Will affect climate
globally. Affect heat of planet. Will
affect sunlight.
May kill Billions of people.
Eg.
Mt St Helen’s, USA
Yellowstone, USA
Geography Homework
• Draw Map on page 23 with a key. Mark all the
attractions on it
• Write out the Mercalli scale for Earthquakes on page
25
• Write out the key terms on page 24 (and learn them)
• Homework for Wednesday 20 th October
• Handouts on MT ST Helen’s
• Handouts on KOBE Earthquake
• Handouts on Sicuchan Earthquake – China
• TSUNAMI’s
Case Study - Montserrat
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•
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•
•
Effects of the Eruptions
Plymouth, the capital city,
covered in ash – became a ghost
town
Villages destroyed – people
made homeless
23 people killed
Forest fires
Floods as valleys were blocked
by ash
Airport and port closed
Farmland destroyed
Tourist industry stopped
Industries crippled
Responses to the eruptions by the
local people
• Evacuation of over 5000 people
abroad, some to Britain
• Others moved to the north of
the island where they lived in
makeshift camps
• Riots occurred as locals
complained that the British
government was not doing
enough.
Responses to the eruptions by the Montserrat
and British governments
•£41 million of aid given
•Temporary shelters provided
•Money given to the people to help
them move to other countries
•Free flights out of the island.
Earthquakes
• Earthquakes are vibrations in the Earth’s crust. The vibrations
usually occur along a fault or plate boundary. The plates become
jammed together. The pressure builds up until eventually the
friction is overcome and the plates jerk past each other. These
sudden movements cause the earthquake.
Earthquake - Focus and Epicentre
• Focus – where the earthquake occurs
• Epicentre – the point on the ground surface directly above the
focus
Focus - The place where Earthquakes begin deep in the crust
Deep focus earthquakes cause less damage than shallow focus ones
(because they are further from the surface).
Epicentre – the point above the focus where the earthquake is most
strongly felt.
Coming out of this point are Shock waves.
Measuring Earthquakes
• The magnitude (size) of an earthquake is recorded using an
instrument called a seismograph, and given a value between 1 and
10 on the Richter Scale. The scale is logarithmic: an earthquake
measuring 6 is 10 times more powerful than one measuring 5.
Class Today
• Recap
• Richter Scale – damage sheet (Picture for each)
• Homework Using case studies of volcanoes in rich and poor parts of the
world, compare and describe the immediate responses. (8 marks)
• Primary and Secondary effects of Earthquakes - notes
• Difference between Effects and Responses to Natural Hazards
• Factfile of Kobe Earthquake - draw simple map (Check Kobe homework)
Tomorrow
• Factfile of Sichuan Earthquake – draw simple world and China map
• Effects and Responses sheet on Sichuan Earthquake
•Homework Using case studies of volcanoes in
rich and poor parts of the world, compare and
describe the immediate responses. (8 marks)
•Nyiragongo Volcanoe and Mt St Helen’s
•Compare – look at the similarities and
differences
•Describe the immediate responses
Emergency Action Plan
•This is planning what to do if an earthquake
hits again
• Hospitals spread out so not all damaged
• Everyone has helmets and gas masks in case
• People know how to evacuate buildings, to not run
and panic
• Store of aid, canned food in houses
• Emergency services – fire brigade, doctors etc all
know what to do
The effects of earthquakes
An earthquake causes both primary and secondary effects
Primary effects (the immediate damage)
• Collapsing buildings and bridges
• Cracked and twisted roads and railways
• Loss of life
• Shock and panic of people affected
Secondary effects
(the after effects of the earthquake)
• Fires caused by fractured gas mains and broken electricity cables.
Broken water pipes often mean there are no water supplies to put fires
out
• Tidal waves and tsunamis often result from an earthquake under the
seabed eg. In 1960 a tsunami killed 165 people in Japan
• Landslides in steep-sided valleys where the rocks are weak sands and
clays
• Disease and famine due to lack of clean water and medical facilitices
• http://www.disastervideo.net/earthquake-what-causes.ph
• http://science.howstuffworks.com/earthquake.htm
Kobe earthquake, Japan
Learning Intention
• Learn a Case study of an Earthquake in a MEDC
• Primary and Secondary effects
• Immediate and Long term responses
Why did it happen?
Case Study – Kobe, Japan 1995
Causes
Kobe lies close to a short fault between the Philippine
and south Japan tectonic plates. The two plates are
sliding past each other. This is called a passive plate
boundary. In January 1995 about 50km of the fault
moved causing the Great Hansin earthquake.
Effects
• Primary (the immediate damage)
• Over 100,000 houses collapsed
• Loss of life – 5500 people killed
• 30,000 people injured
• Roads and railways wrecked
• Electricity, gas and sewerage systems destroyed
• 10% schools destroyed
• 12% industry and 14% services destroyed
• Emergency services disrupted
•
•
•
•
•
•
•
•
•
Secondary (the after-effects)
300,000 people homeless
Landslides
Huge fires
Stress and shock
2 million homes without power
1 million homes with no water for 10 days
Health hazards in the makeshift shelters
A flu epidemic
Responses
• Emergency Action
• Emergency services and the army brought in from
other areas to help.
• Heat seeking equipment to find people.
• Emergency shelters
• Mobile telephone systems
• Water and food supplies brought in
• Hospitals set up in schools
• Putting out fires
•
•
•
•
Medium/long-term plans
Bulldozing unsafe buildings
Rebuilding homes, schools, roads, hospitals etc
Repairing water, electricity, phone and sewerage
systems
• Provide help for those in shock
• More monitoring equipment
• Introduce an emergency action plan
Causes
•
Kobe lies close to a short fault between the
Philippine and south Japan tectonic plates.
•
The two plates are sliding past each other. This
is called a passive plate boundary.
•
In January 1995 about 50km of the fault moved
causing the Great Hansin earthquake.
Effects
•
•
•
•
•
•
Primary (the immediate damage)
Over 100,000 houses collapsed
Loss of life – 5500 people killed
30,000 people injured
Roads and railways wrecked
Electricity, gas and sewerage
systems destroyed
• 10% schools destroyed
• 12% industry and 14% services
destroyed
• Emergency services disrupted
Secondary (the after-effects)
300,000 people homeless
Landslides
Huge fires
Stress and shock
2 million homes without power
1 million homes with no water for 10
days
Health hazards in the makeshift
shelters
A flu epidemic
Responses
Emergency Action
• Emergency services and the
army brought in from other
areas to help.
• Heat seeking equipment to find
people.
• Emergency shelters
• Mobile telephone systems
• Water and food supplies
brought in
• Hospitals set up in schools
• Putting out fires
Medium/long-term plans
• Bulldozing unsafe buildings
• Rebuilding homes, schools,
roads, hospitals etc
• Repairing water, electricity,
phone and sewerage systems
• Provide help for those in shock
• More monitoring equipment
• Introduce an emergency action
plan
Siuchan Earthquake
• The Sichuan Earthquake
• When did it happen and how?
• 12th May 2008 at 2.28pm.
• The pressure caused by the Indian Plate colliding with the Eurasian
Plate was released along the Longmenshan Fault line that ran
beneath Sichuan.
• This made an Earthquake measuring 7.9 on the Richter Scale.
• Tremors last 120 seconds.
Effects
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Initial deaths were 8,700.
11 days later death toll was 55,000.
2 months later death toll was 69,000.
18,000 were missing.
374,000 injured.
Between 5-11 million homeless (Secondary Effect)
80% of buildings collapsed in Beichuan County (a rural area – built before
building codes introduced).
5 million buildings collapsed – including a number of schools.
900 Pupils were killed in Juyuan Middle School in Dujiangyan city.
Anger among parents about cheap building materials used to build these
schools.
Communications (roads, rail, airports, buses/Transport) brought to a halt.
Neither land nor mobile phones worked in Wenchuan.
Roads and some rivers were blocked by landslides. The blocked rivers led
to fears of flooding. (Secondary Effects)
Cost predicted at $75 million.
Immediate Responses
• Dismay that areas in Wenchuan not reached within 30 hours of quake –
access was impossible.
• 20 Helicopters sent to rescue and start relief efforts immediately after
disaster.
• Troops parachuted in to assess situation, while others hiked on foot Thousands of army troops deployed after Earthquake.
• Large scale efforts made to free trapped survivors from collapsed buildings
•.
• Immediate needs were clean water, food supplies and tents for shelter from
the spring rains.
• Increased the making of tents to meet the 3.3 million needed - Land
flattened to allow tents to be set up.
• On 14 May China requested International help (why so long? 2 days later) –
teams from Japan, Russia, and South Korea joined the rescue effort (but
cash donations were the preferred option to help).
Long Term repsonses
• Donations to Red Cross were over £100 million 2 weeks after the
disaster – most monet went to:
• Run camps, ensure food, medicines and doctors available, tents had
mattresses and blankets and volunteers were available.
• 1 million temporary small homes will be built to house those made
homeless.
• Vice Governor of Sichuan hoped rebuilding would be done in 3
years.
• Chinese Government pledged a $10 million rebuilding fund.
• Banks wrote off debts (money owed to banks) owed by survivors
who did not have insurance.
Prediction, protection and Preparation
The three P’s (Prediction, Protection and
Preparation) provide the key to trying to
reduce the damage of Earthquakes.
• Prediction – Attempts top predict where and when an
Earthquake will happen (based on current knowledge).
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• Japan tries this in belief a warning can be given, but did not happen with
Kobe.
• Foreshocks do occur (shocks before main shaking), but not in enough
time to evacuate.
• Experts know where Earthquakes are likely to happen but struggle with
when.
• Looking at time between earthquakes does not help
• Experts have difficulty in pinpointing exactly where along margin it will
hit.
• Animal behaviour has been used in the East to predict. People sceptical in
the USA about this.
• China evacuated Haicheng (1 million people) in 1975 partly due to strange,
unexplained animal behaviour – earthquake, 7.3 on Richter Scale hit days
later. Few deathgs but 150,000 would have died without evacuation.
Protection – Constructing buildings so that they are safe to live in
and they will not collapse.
• Build to an appropriate standard. Use designs to stop movement.
Preparation – Organising activities and drills so that people know
what to do in the event of an earthquake.
• Hospitals, emergency services and all local people practice for
major disasters. Have drills in Public buildings eg. Schools.
• Have a code of practice – people know what to do to reduce
impact/damage to people/buildings and increase chance of living.
Impact of tectonic activity
The impact of earthquakes and volcanoes is often more severe:
• In urban areas rather than rural areas
• In LEDCs rather than MEDCs
Other factors important
The magnitude of the earthquake is often less
important than where the earthquake occurs.
You need to know why!
Think about:
1. the population density,
2. the types of buildings,
3. the availability of emergency services and early
warning systems and communications
Impact of tectonic activity
Why do so many people choose to live in earthquake zones or
near volcanoes?
Near volcanoes there may be many advantages:
• Fertile soils when the lava weathers
• Jobs in tourism eg. Trips to see the crater, souvenir shops
and hotel accommodation
• Minerals, eg. Sulphur and pumice
• Hot springs for bathing and heating
• Heat used to generate electricity
Case study for advantages of living near
volcanoes
Vesuvius and the Plain of Campania
• Fertile soils – for wheat, tomatoes, peaches, almonds and
vines with yields 5 times higher than the national average
• Tourism – trips to Vesuvius and hot springs, museums at
Pompeii and Herculaneum
• Minerals – the sulphur wasteland nearby at the Phlegraean
Fields
Remember
• For some people it may be the best farmland available eg.
Montserrat and near Vesuvius
• Some people may not be able to afford to move anywhere else
• Others may believe that an eruption or earthquake will never
happen in their lifetime
Keyword Keywords Definition
Acid lava
Thick, viscous lava with a
high silica content, flows
short distances
Basic Lava
Thin, ‘runny’ lava, low silica
content, flows long distances
Composite volcano
Steep-sided cone with layers
of ash and lava
Where 2 plates are moving
together (destructive)
Compressional margin
Earthquake
A shaking of the Earth’s
crust
Keyword Keywords Definition
Fold mountains
Richter Scale
Mountains formed by plate
movements
Measures the strength of an
earthquake
Shield volcano
Gentle sides, wide base made of
basic lava
Tectonic Plate
A huge section of the Earth’s crust
Volcano
A cone-shaped mountain created
by lava from repeated eruptions
Tensional margin
Where 2 plates are moving apart
(constructive)
Volcanoes Videos
• http://www.classzone.com/books/earth_science/terc/navigation/vis
ualization.cfm
• http://blip.tv/play/AZ6XNIW6bw
• http://blip.tv/play/AavAK4W6bw
• http://blip.tv/play/AafFf4W6bw
• Montserrat - http://blip.tv/play/gbAAn9tThbpv
• Volcanic eruption -
Earthquakes
• San Andreas fault - http://blip.tv/play/AajDCoW6bw
• Kobe earthquake – http://www.youtube.com/watch?v=vi9iRbC7He0
Tsunami’s
http://news.bbc.co.uk/1/hi/4136289.stm
At-a-glance: Countries hit
(see handout for Tsunami notes)