Year 11

GCSEPLATE TECTONICS

Learning intentionT

he 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• The Earth’s structure has 3 parts:

1. Core – at the centre

2. Mantle – a large mass of molten rock surrounding the core

3. Crust – the surface of the Earth. A thin layer ‘floating’ on the mantle.

Crust•T

wo 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•P

lates move apart eg. N. American and Eurasian plates•G

ap filled by rising magma from the mantle•R

ising magma forms shield volcanoes•M

ost 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 marginThis 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 boundariesSubduction 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 marginsCollision 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 marginsAt 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•P

lates 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

Andes

Rockies

Alps

Himalayas

Appalachian

Urals

http://www.platetectonics.com/book/page_11.asp

Copy diagram of fold mountains into books

Fold Mountains

Large depressions called Geosynclines form between plates. Seas filled the geosynclines.

Over millions of years, the sediments were compressed (squeezed), by their own weight, into sedimentary rocks eg. Sandstone, limestone.

Rivers flowing into the geosynclines carried sediments (sand and silt) which built up on the sea bed

Compression

Geosyncline

Sea Plates Plates

Sediments compressed and folded into Fold

Mountains

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•F

old 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•F

old 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

VolcanoesTy

pes of volcanohttp:/

/video.nationalgeographic.com/video/player/environment/environment-natural-disasters/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.

VolcanoesTh

ey 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•U

se 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 volcanoesC

haracteristics:•S

teep 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

Examples: Mount Etna, Vesuvius, Mount St Helens

Shield (basic lava) volcanoes•E

xamples: 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•T

hese 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•T

ake down notes from notebook•D

efinition 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 VolcanoesTiltm

eters – 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.•S

cale – 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 SupervolcanoeShape Steep sided, cone

shape. Has a crater.Supervolcanoes are flat, surrounded by higher mountains.

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

Eg.

All life gone within a few miles. Can effect local climate. May kill 100’s of people

Mt St Helen’s, USA

Devastating effects within 200km – all life gone. Will affect climate globally. Affect heat of planet. Will affect sunlight.

May kill Billions of people.

Yellowstone, USA

Geography Homework•D

raw 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 20th October

•Handouts on MT ST Helen’s

•Handouts on KOBE Earthquake

•Handouts on Sicuchan Earthquake – China

•TSUNAMI’s

Case Study - MontserratE

ffects of the Eruptions•P

lymouth, 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•E

vacuation 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•E

arthquakes 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•T

he 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•R

ecap

•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•T

his 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•L

earn a Case study of an Earthquake in a MEDC•P

rimary and Secondary effects•I

mmediate and Long term responses

Why did it happen?

Case Study – Kobe, Japan 1995C

auses

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•P

rimary (the immediate damage)•O

ver 100,000 houses collapsed•L

oss of life – 5500 people killed•3

0,000 people injured•R

oads and railways wrecked•E

lectricity, gas and sewerage systems destroyed

•10% schools destroyed

•12% industry and 14% services destroyed

•Emergency services disrupted

Secondary (the after-effects)300,000 people homelessLandslidesHuge firesStress and shock2 million homes without power1 million homes with no water for 10 daysHealth hazards in the makeshift sheltersA flu epidemic

ResponsesE

mergency Action•E

mergency 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•T

he Sichuan Earthquake•W

hen did it happen and how?•1

2th May 2008 at 2.28pm. •T

he 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

•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

•.•I

mmediate 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 PreparationThe 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).

••J

apan 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•F

or 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

KeywordsKeyword 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

Compressional margin Where 2 plates are moving together (destructive)

Earthquake A shaking of the Earth’s crust

KeywordsKeyword Definition

Fold mountains Mountains formed by plate movements

Richter Scale 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•h

ttp://www.classzone.com/books/earth_science/terc/navigation/visualization.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•S

an Andreas fault - http://blip.tv/play/AajDCoW6bw•K

obe 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)