Hazardous Earth: Climate Flashcards
(133 cards)
1
Q
Atmospheric Circulation/ Coriolus Effection
A
> Earth rotates, so air doesn’t flow in a straight line. As air moves above the Earth’s surface, planet rotates, so winds follow a curved path.
2
Q
Effect of jet streams on climate
A
> Position of jet stream determines weather we get.
They are mostly at main circulation cells’ boundaries.
If the polar front jet is positioned north of the U.K = warmer weather.
If the polar front jet is positioned south of the U.K = colder weather.
If the polar front jet is positioned in the middle of the U.K= windier and wetter weather.
3
Q
Jet stream
A
> A current of rapidly moving air that is usually several thousand miles long but relatively thin.
4
Q
Cyclones
A
> A tropical storm that occurs over warm seas and oceans. Smallest type of tropical storm, but winds can still reach over 250 mph.
Occur between 20’S and 30’N of the Equator, over 27’C, 60m deep water as they take heat from oceans.
Low pressure.
Small - 650km across.
High wind speeds 300kmph as don’t use much energy.
Formed over small areas as well.
Die out over land because doesn’t get enough warm, moist air.
Cyclones formed in the Indian Ocean and South Pacific move in a westerly direction towards Asia.
5
Q
Cyclones 2
A
> Mb = measurement of air pressure.
Lower pressure = heavy air.
Storm surge = flooding from the sea.
1. Warm air currents rise from the ocean and updrafts of rushing and rising air condense quickly into cumolonimbus clouds.
2.The cyclone tracks away from its source.
3. If it goes over landmass, it will lose mass and slowy die.
Track of cyclone = way it’s heading.
Eye of cyclone = centre of cyclone, mostly free of a storm.
6
Q
Cyclone Alia
A
> 2009, Bangladesh.
7
Q
Bangladesh (Cyclone Alia)
A
> Bangladesh is in Asia.
Flat country with majority of country less than 10m above sea level.
One of the poorest countries - GDP per capita = $3,600.
Flat country so floods can spread very quickly.
Build up of sediment makes sea floor rise, so floods will be more common in the future.
On average, Bangladesh receives around 2911mm of rainfall a year.
8
Q
Cyclone Alia - Case Study
A
> Started in the Bay of Bengal, 25th May 2009.
120mm of rainfall in just a few hours.
Wind speeds reached 360km/h 120 (80km/h for cyclone to start).
Air pressure was very low (967mb), causing rise in sea level and storm surge.
Total fatalities: 339
Highest wind speed: 120 km/h
Date: 26 May 2009 – 27 May 2009
Damage: $295.6 million (2009 USD)
Category: Category 1 Hurricane (SSHWS)
3,500,000 were affected.
750,000 homes were destroyed.
200,000 still living in temporary after 1 year.
A cyclone-proof house in US$ = $1500.
45,000 cyclone warning volunteers in Bangladesh.
LEDC country longer recovery period after cyclone.
9
Q
Impacts of Cyclone Alia
A
> SHORT-TERM IMPACTS:
-No one can work to earn money to rebuild homes + belongings.
-Humans + animals were killed.
-Flooding and no clean water, trees uprooted.
LONG-TERM IMPACTS:
-Education disrupted, government couldn’t fund repairs, 1 classroom for 200.
-People died and homes destroyed.
-Many couldn’t regrow crops because land and water was salty.
-Lack of wood as many trees were dying.
10
Q
Cyclone Alia (Disaster and response)
A
> Oxfam, Christian Aid, Water Aid gave relief aid to victims.
Aid is vital - countries who deal with regular crisis can’t afford to keep rebuilding people + houses.
Soap, food, clothes and temporary shacks given out.
11
Q
Cyclone Hazards
A
> HIGH WINDS:
-Cyclones can produce 250kmph winds.
-People and animals hit by flying debris.
-Trees uprooted.
STORM SURGES:
-Sea rises in low mb.
-Houses are damaged and people injured.
-Erodes beaches, damages coastal defences and flow inland and contaminate.
Intense rainfall, landslides, coastal flooding.
12
Q
Hurricane Katrina
A
> Left $150 billion’s worth of damage.
Passed through Florida, 25th August 2005.
1836 people died and 10,000 were made homeless.
3,000,000 people were left without electricity.
53 breeches of levees and flood walls.
80% of New Orleans flooded up to 3m deep.
Homes and businesses were looted.
Roads and bridges were damaged.
13
Q
Reducing the impacts
A
> WEATHER FORECASTING:
-Sends out weather reports and warning on TV, radio and phones.
-Allows people to prepare for storm, households with radio had a lower death rate.
-Not everyone has access to radio etc.
SATELLITE TECHNOLOGY:
-Digital images from space to see if storm is brewing.
-Warning to meteorologists to tell people to prepare.
-Expensive, but Bangladesh is developing it’s own $150 million one.
STORM SURGE DEFENCES:
-Walls built in sea to stop sea level rising and flooding land.
-Stops major floods in flood-prone areas.
-If they break can’t get water back out to sea as they block it.
14
Q
USA Preparation
A
>Weather forecasting >Satellite technology >Warning systems >Evacuation strategies >Storm surge defences
15
Q
USA Preparation (Weather forecasting)
A
> Very reliant
Can warn millions
If inaccurate satellite recordings then the weather forecast is wrong.
16
Q
USA Preparation (Satellite technology)
A
> There’s over 20
They aren’t perfect
They break
17
Q
USA Preparation (Warning systems)
A
> SMS (103phones/100people)
>Poor might not be aware.
18
Q
USA Preparation (Evacuation strategies)
A
> Evacuation.
>Some might not evacuate.
19
Q
USA Preparation (Storm surge defences)
A
> Prevents potential flooding (levees)
Levees can break eg 700 people drowned in one small suburb when one broke.
Government spending cuts left them poorly maintained.
20
Q
Saffir-Simpson Wind Scale
A
> Most common scale used to classify tropical cyclones.
Based on wind speeds generated by tropical cyclones.
Estimates amount of damage on property and environment.
Tropical cyclones over category 3 have potential to cause major life loss and significant damage.
21
Q
Category 1
A
> 119-153km/h
Minimal
1.2m-1.7m storm surge.
22
Q
Category 3
A
> 178-208km/h
Extreme
2.7-3.8m storm surge
23
Q
Category 5
A
> 250+km/h
Catastrophic
5.4m+ storm surge.
24
Q
Key events: Hurricane Katrina: August
A
- 23rd: Tropical depression forms off the South-eastern Bahamas.
- 24th: Upgraded to tropical storm - Katrina.
- 25th: Became hurricane, making landfall in Florida.
- 26th: Intensified to category status 2 when crossing Gulf of Mexico.
- 27th: Doubled in size, category 3, heads towards Mexico.
- 28th: Peak category 5, approaches U.S coast, 282km/h wind speed,902mb.
- 29th: Land fall eastern edge of New Orleans.
- 30th: Follows course of Mississippi downgrading to a tropical depression near Clarkesville, Tennesse.
25
Evidence for tectonic plates
1. Study of fossils - similar fossils are found on different continents. This is evidence that these regions were once very close or joined together.
2. Pattern of rocks - similar pattern of rock layers on different continents is evidence that the rocks were once joined together.
3. Shape of continents - jigsaw.
26
Layers of the Earth
```
Inner core
Outer core
Lower Mantle
Upper Mantle
Oceanic Crust
Continenantal crust
```
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Lithosphere
>The uppermost layer of the Earth.
>It's cool and brittle.
>It includes the very top of the upper mantle, the oceanic crust and continental crust.
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Asthenosphere
>Top layer of the mantle.
>35-250km.
>3.4-4.4g/cm^3.
>Partially molten.
>Composition: peridotite.
>Temp: 900-1600 degrees.
>The movement of tectonic platers is evidence that there is a 'lubricating' layer underneath the lithosphere. This is the asthenosphere.
>Geologists think the asthenosphere is partly molten rock and partly solid rock.
>We need to learn more from research like that done on drilling ships.
29
Continental Crust
```
>Density: 2.7g/cm^3.
>Solid, thick - 30-50km.
>Lighter rocks, cannot subduct into the mantle.
>Old.
>Granite
>Temp: Air-900 degrees.
```
30
Oceanic crust
```
>Density: 3.3g/cm^3.
>Dense basalt, can subduct into the magma of the mantle.
>Young.
>Thin: 6-8km.
>Temp: Air - 900degrees.
```
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Mantle
>The mantle is the largest of the Earth's layers by volume, and is mostly solid rock.
>We know this because sometimes you can see the top of the mantle attached to an overturned piece of crust.
>Upper mantle: 700km.
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Lower mantle
```
>Density: 4.4-5.6g/cm^3.
>Solid.
>Composition: Peridotite.
>Temp: 1600-4000 degrees.
>2900km
```
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Outer core
```
>Density:9.9-12.2g/cm^3.
>Liquid.
>Iron and nickel.
>4000-5000 degrees.
>5270km
```
34
Inner core
```
>Density: 12.6-13.0g/cm^3.
>Solid.
>Iron and nickel
>5400 degrees.
>6370km
```
35
What do earthquake waves tell us?
>Earthquake waves tell us about the physical state of the Earth.
> They speed up, change direction or stop when they meet a new layer in the Earth.
>Some waves travel easily through the crust, mantle and inner core, but not through the outer core. This suggests that the outer core has a different physical state and may be liquid.
36
Clues from space
>Evidence for Earth's composition can come from meteorites.
>Most come from the asteroid belt between Mars and Jupiter.
>Metorites come in several types:
-stony meteorites,with a similar composition to basalt.
-stony-iron meteorites, containing a lot of the mineral olivine.
-iron meteorites, which are solid lumps of iron and nickel.
>These meteorites may be fragments of the lithosphere, mantle and core of a shattered planet.
>Iron meteorites may show that the Earth's core is made up of iron and nickel.
37
Meteorite - definition
>Fragments of rock and metal that fall to Earth from space.
38
Convection currents
>Convection currents contribute to plate movement:
1. The core heats the molten rock in the mantle to create a convection current.
2. Heated rock from the mantle rises to the Earth's surface.
3. At the surface the convection current moves the tectonic plates in the crust.
4. Molten rock cools and flows back to the core to be reheated.
39
Where does the earth get its heat from?
1. Primordial heat: created during the great bombardment, meteorites hit the Earth and this kinetic energy was transferred to heat. Which is still keeping the planet warm today.
2. Radioactive Decay: the process by which an unstable atom loses energy by emitting particles of radiation and heats the planet.
40
Magnetic field
>The Earth is surrounded by a huge, invisible magnetic field called the magnetosphere.
>This is a force field which you can sometimes see, better known as the northern lights or aurora boreails.
>These form when radiation from space hits the magnetosphere and lights up the sky.
>The magnetosphere protects the Earth from harmful radiation from the space and sun.
>The Earth's magnetic field is made by the outer core. As liquid iron in the outer core flows, it works like an electrical dynamo. This produces the magnetic field.
41
Hot rocks
>Inside the Earth is hot. We know this because of:
-molten lava spewing from active volcanoes.
-hot springs and geysers.
>Heat from inside the Earth is called geothermal.
>The heat is produced by the radioactive decay of elements such as uranium and thorium in the core and mantle.
>This raises the core's temp to over 5000 degrees.
42
Geothermal- definition
>Heat from inside the Earth.
43
Radioactive decay - definition
>Atoms of unstable elements release particles from their nuclei and give off heat.
44
Plumes - definition
>The parts of convection cells where heat moves towards the surface.
>These are concentrated zones of heat.
45
Plumes
>In a plume, the mantle is less dense.
>Plumes bring the magma to the surface.
>If magma breaks through the crust, it erupts as lava in a volcano:
-some plumes rise like long sheets of heat. These form divergent plate boundaries at the surface.
-other plums are like columns of heat. These form hot spots. Hot spots can be in the middle of a tectonic plate, like in Hawaii and Yellowstone in the USA.
46
Moving plates
>Today, the Earth's lithosphere is split into 15 large tectonic plates and 20 small ones.
>The plates move very slowly on the asthenosphere.
>Where 2 plates meet there's a plate boundary.
>There's 3 types of plate boundary.
>Most earthquakes and volcanoes are found on plate boundaries.
47
The 3 types of plate boundary
1. Divergent plate boundaries - formed when 2 plates move apart.
2. Convergent plate boundaries - formed when 2 plates collide.
3. Conservative plate boundaries - formed when 2 plates slide past each other.
>Also collision zones
48
Conservative Plate Boundary
>Here the two plates are sliding past each other. When the plates stick it causes tension to build up. When this is released an earthquake occurs.
>An example of this is on the San Andreas fault line in Los Angeles.
>Here crust is neither created nor destroyed.
>Rare, but destructive, because they are shallow.
>Destructive earthquakes up to magnitude 8.5 with small tremors alsmost daily.
>No volcanoes.
>Pacific and North American Plates.
49
Collision Zone
>Here, 2 plates are moving towards each other.
>As both plates are continental neither of them can be subducted.
>Therefore the crust is crumpled upwards to form fold mountains.
>An example of these would be the Himalayas, where the Indian plate has collided with the Eurasian plate.
>Destructive earthquakes up to magnitude 9. Landslides are triggered too.
>Volcanoes are very rare.
>Earthquakes happen on faults in collision zones, e.g. 2015 earthquake in Nepal.
50
Divergent Plate Boundary
>Here, two plates are moving apart from each other.
>This causes the magma to rise up from the mantle and form new oceanic crust.
>This process normally occurs under oceans, and results in the formation of underwater volcanoes.
>Some of these become so large they appear above sea level such as Iceland. Iceland on North Atlantic Ridge, Eurasian and North American plates are moving apart.
>Small earthquakes up to 5.0-6.0.
>Not very explosive or dangerous volcanoes, they occur in fissures, erupt basalt lava at 1200 degrees, which is very hot and runny.
>It forms lava flows and shallow sided volcanoes.
>Small earthquakes due to friction as plates tear apart.
51
Convergent plate boundary
>Here the 2 plates are moving towards each other.
>However the oceanic crust is being pushed underneath the continental plate as it's far denser.
>This forms a deep sea trench.
>Oceanic crust is melted into magma by the mantle.
>This then rises along the fault lines to form volcanoes.
>Very destructive earthquakes up to 9.5, tsunami can form.
>Very explosive, destructive volcanoes, steep sided, cone-shaped, erupt andesite lava at 900-1000 degrees.
>Andes Mountains in Peru and Chile.
>As plates push together, oceanic plate is subducted. As it sinks, it melts and creates magma called andesite.
52
Fissure - definition
Cracks in the crust
53
Active volcano
liable to erupt e.g. Mt Etna
54
Dormant volcano
a volcano which has not erupted for many years e.g. Mt Pinatubo erupted in 1991 after 500 years of dormancy.
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Extinct volcano
a volcano which has not erupted for many thousands or millions of years e.g. Edinburgh. No longer have a supply of magma.
56
VEI
>Volcanic Explosivity Index.
| >Measures the destructive power of a volcano from 1 to 8 - humans have never experienced any over 4.
57
Ash - definition
fine material thrown out by a volcano
58
crater - definition
a bowl shaped opening in a volcano
59
erupt - definition
when a volcano erupts its magma
60
lava - definition
molten rock flowing out of the ground
61
magma - definition
molten rock below the earths surface
62
magma chamber - definition
where molten lava is found below the earths surface
63
pyroclastic flow - definition
a mixture of extremely hot ash, rock and lava blasted out of a volcano at very high speeds.
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vent - definition
an opening in the earths surface
65
volcanic bomb - definition
large rock fragments thrown out by volcano
66
lahar - - definition
a river of mud, ash and debris
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volcano - definition
a cone shaped mountain that is made from layers of rock and ash
68
Hot spot theory
>Volcanoes and earthquakes occur at plate boundaries except at hot spots.
>Hot spots occur when superheated plumes of magma rise up through the mantle. As it reaches the crust due to the high temperatures it melts through the crust, which magma rises through forming a volcano.
>Tectonic plate will move breaking away the volcano's magma chamber and a new volcano will form.
69
Two types of volcano
1. Composite
| 2. Shield
70
Composite volcano
>Are found on destructive plate boundaries.
>Are formed by eruptions of viscous, sticky lava and ash that don't flow far.
>Have steep sloping sides and a narrow base.
>Are made up of layers of thick lava and ash.
>Contain andesitic magma which is less hot then basaltic magma but but which contains lots of silica and gas.
>Erupt infrequently but violently, including pyroclastic flows (mix of ash, gases and rock).
>Explosive with ash cloud.
71
Shield volcanoes
>Are found on constructive plate boundaries or hot spots.
>Are formed by eruptions of thin, runny lava which flows a long way before it solidifies.
>Have gently sloping sides and a wide base.
>Contain basaltic magma which is very hot with low silica and gas content.
>Erupt frequently but not violently.
>Not explosive - no ash cloud
72
List of dangers of an earthquake
1. Gases
2. Pyroclastic flows
3. Ash clouds
4. Lahars
5. acidic lava
6. basic lava
7. bombs
73
Dangers of an earthquake - gases
>Sulphur dioxide, carbon dioxide and hydrogen sulphide.
74
Dangers of an earthquake - pyroclastic flows
>At a convergent plate boundary, viscous lava.
>Glowing cloud of burning hot ash, rosks, steam and gases.
>It can move in excess of 200mph and can reach 1000 degrees Fahrenheit.
>Usually destroys everything in sight.
75
Dangers of an earthquake - ash clouds
>Fine clouds of dust which can be blown a long way.
>In extreme circumstances they can cause asphyxiation.
>Majority of them just make the day seem gloomy and of course stop air travel.
76
Dangers of an earthquake - lahars
>Occur when water and volcanic ash mix - they are mud-flows which can reach very high speeds and be extremely dangerous.
77
Dangers of an earthquake - acidic lava
>Highly acidic and full of gas.
78
Dangers of an earthquake - basic lava
>Flows a long way
79
Dangers of an earthquake - bombs
>These are red hot boulders and rock fragments which are blasted out of volcanoes along destructive margins.
>Can travel hundred of meters and can kill instantly.
80
Developed world example of an active volcano
>Mount Sakurajima, Japan.
81
Sakurajima, Japan
>Japan is on a convergent plate boundary where the Pacific plate is subducted beneath the Eurasian plate, causing active volcanoes.
>This causes active volcanoes with high VEI's.
>Sakurajima has been erupting violently since the 1950s, however people continue to live there due to the benefits the volcano can bring.
>Also, as Japan is a developed country, it's able to afford money on monitoring, protection and evacuation.
>People can afford insurance against damage and the government helps.
>In developed countries with protection and prediction, the costs are mainly economic not social.
82
Mount Sakurajima
>Volcano type: steep-sided stratovolcano over 1000m high.
>Magma type: andesite. High gas content, high viscosity.
>Explosivity: VEI 4-5.
>Hazards: Lava flows, volcanic bombs, pyroclastic flow, ash fall. Erupts almost continually, but with a major eruption every 200-300 years.
83
Benefits of volcano - Sakurajami
>40% of land is fertile volcanic soil growing tea and rice.
>There are lots or urban areas around the bay.
>7000 people live at the base of volcano.
>Hot springs and lava flows are popular attractions; the area is a national park.
>The sheltered bay makes a good port and fishing is an important industry.
84
problems of volcano - sakurajima
>Kogoshima has a population of 650,000: a big eruption could devastate it with ash, lava bombs and pyroclastic flows.
>Today, the volcano hurls volcanic bombs over 3km from its crater. Pyroclastic flows are 2km long. 30km^3 of ash erupt each year.
85
How sakurajima is monitored and evacuation process
>Aircrafts are used to measure the amount of gas the volcano gives off.
>Tiltmeters detect when the volcano swells up as it fills with magma.
>Boreholes measures water temperatures as magma heats it up.
>Hot springs are monitored.
>Concrete shelters protect against volcanic bombs and ash.
>Evacuation routes clearly sign posted; regular evacuation drills.
>Concrete lahar channels divert dangerous mudflows.
>A tunnel in the volcano has seismometers. There monitor earthquakes, which increase as magama rises so scientists can predict an eruption.
>Protection and prediction.
86
Developing world example of a volcano
Mount Nyiragongo, Democratic Republic of Congo.
87
Mt. Nyiragongo - background
>It's a large active volcano, found at a divergent plate boundary, where continental crust is being pulled apart.
>This has caused the Great African Rift Valley (where crust has sunk) and magma has risen, creating volcanoes.
>N has some of fastest running lava in world, and also releases large amounts of CO2 both of which threaten the city of Goma below.
>Goma and the surrounding areas rely heavily on aid from NGOs to manage and recover from the effects of this volcano.
88
Mt. Nyiragongo
>Volcano type: stratovolcano over 3400m high but less steep than Sakurajima, shield volcano.
>Magma type: basalt. Low gas content, very low viscosity.
>Explosivity: VEI - 1.
>Hazards: lava flows and gas emissions. contains a lava lake within its crater, which can drain causing huge, fast-moving lava flows.
>In January 2002, a fast flowing river of basalt lava poured out of Mt. Nyiragongo and into the city of Goma.
89
Social impacts of nyiragongo eruption
>100 people died, mostly from poisonous gas and getting trapped in lava.
>12,500 homes destroyed by lava flows and earthquakes. Eruption was predicted so 400,000 evacuated to overcrowded refugee camps.
>Over 120,000 left homeless.
>Disruption to mains water supplies caused concern about spread of diseases.
>Destroyed 40% of Goma.
>Water and electricity supplies cut off, including schools and half of airport was covered in lava.
90
Economic impacts of nyiragongo
>poisonous gases - acid rain which affected farmland and cattle - many farmers lost income.
>Due to poverty, most couldn't afford to rebuild their homes.
91
Relief effort - nyiragongo
>With little clean water and shelter, diseases like cholera could spread. The UN and Oxfam relief effort to help:
- UN sent in 260 tonnes of food in 1st week. Families got 26kg of rations.
- In UK, a TV appeal asked people to give money to help.
- governments around the world gave $35 million to get aid to refugees.
- emergency measles vaccinations were carried out by the World Health Organisation.
92
Recovery lengths - nyiragongo
>It was months before many could start building new homes.
>By June 2002, however, some roads had been cleared of lava and water supplies and been repaired.
>Mt. N is still active and could erupt at any time.
>Threats different to Mt. Sakurajima. Gases like CO2 and sulphur dioxide rise into the lake and get trapped in lake bottom muds. Earthquakes shake these gases free.
>In 1986, this happened to volcanic Lake Nyos in Cameroon, and also in Africa.
>1,700 people suffocated from breathing in too much CO2.
93
Nyiragongo - protection/prediction
>volcano observatory, which assesses volcanic activity and teaches people about dangers of living near a volcano.
>Practice drills have taken place to assess effectiveness of policing, charity and people.
>Built Goma on lava flows and volcanic material.
94
Eathquakes
>Caused by plate movements and friction.
>Measured on the Richter Scale.
>Not possible to predict.
>Nearer the surface, the more damage.
>Occur along fault lines.
>Huge masses of rock are being scraped together.
>When pressure gets too strong, one rock mass gives way.
>The energy released is in seismic waves.
95
Focus - definition
>The point of origin of an earthquake.
96
Epicentre - definition
>The point on the ground directly above the focus of an earthquake.
97
Relationship between focus and epicentre
>The shaking is worse on the surface if the focus is shallow.
>The closer the focus and epicentre, the more destructive the earthquake.
>Energy travels outwards from the focus as earthquake waves.
>Epicentre experiences most shaking.
98
Magnitude - defintion
power of an earthquake
99
Seismometer - defintion
a machine for recording and measuring an earthquake using the richter scale.
100
The Richter Scale
>0-2: not felt.
>2-4: minor.
>4-5: small (damage begins but deaths are rare).
>5-6: moderate.
>6-7: strong.
>7-8: major (lots of devastation and deaths).
>8-9: great (huge devastation).
>Every 1 up on scale = 10 times stronger.
101
Developed World Earthquake
>On 11th March 2011, an earthquake hit the region of Sendai in Japan.
>Magnitude: 9.0.
>Focus: 30km deep on a convergent plate boundary.
>Epicentre: 70km from coast in Sendai Bay.
>Subduction zone between Eurasian and Pacific plates.
>Triggered 40m tall tsunami, which flowed 10km inland.
102
Japan Earthquake 2011 - primary effects
>1 dam collapsed, 2 nuclear power stations fractured, and an oil refinery set on fire by damaged gas pipes.
>Tohoku motorway badly damaged in northern Japan. Sendai airport closed. One rail link near Sendai badly damaged.
>Fukushima Nuclear power plant.
>Fires - north-eastern Japan.
>US$235 billion of damage caused by earthquake and tsunami combined - costliest disaster in history.
103
Japan Earthquake 2011 - secondary effects
>These were caused by tsunami.
>15,900 people died, 2600 missing, 6150 injured and 350,000 homeless.
>Most were at work or at school when it struck at 2.46pm.
>93% of deaths caused by drowning.
>2 nuclear reactors went into meltdown because flooding damaged the cooling systems. Local people were evacuated and had not returned until 2015.
>Businesses disrupted by damage, clearance and rebuilding.
>Homelessness, disrupted schooling, unemployment and increased stress lasted for years as the authorities struggled to cope with damage.
104
Japan - long-term planning
>The secret of survival is planning. Japan is a developed country, so it can afford to do this, There's a 70% probability of a magnitude 7.2 earthquake hitting Tokyo in the next 30 years. There is no way of predicting when this might happen, but planning helps.
>Each year Japan has earthquake drills. Emergency services practice rescuing people. People keep emergency kits (water, food, a torch and radio) at home.
>Many buildings are earthquake-proof. Gas supplies shut off automatically, reducing fire risk.
>Tsunami walls have been designed to protect the coast.
105
Japan Earthquakes - responses, general
>Everyone receives a text.
>Computer operated announcements.
>Shut-down reactors automatically. Emergency diesel generators started to try and cool nuclear core of reactors.
>Japan Meteorological Agency provides warning systems on radio, phones and TV.
>Uses speed difference between P and S waves in warning system. Technical limitations - only matter of seconds if you are close to epicentre = not enough time + not always accurate.
>Traffic control centre orders train to stop.
106
Developing World earthquake
>On 12th January 2010, a magnitude 7.0 earthquake hit Port-au-Prince, Haiti.
>Magnitude:7.0
>Focus: 13km deep on a conservative plate boundary.
>Epicentre: 25km from Port-au-Prince (pop=2.5 million).
107
Haiti earthquake - primary effects
>316,000 people died and 300,000 injured.
>Many homes were poorly built and collapsed instantly.
>1 million made homeless.
>The port, communication links and major roads were damaged beyond repair. Rubble from collapsed buildings blocked road and rail links.
108
Haiti earthquake - secondary effects
>The water supply systems were destroyed - a cholera outbreak killed over 8000 people.
>The port was destroyed - making it hard to get aid to areas.
>Haiti's important clothing factories were damaged. These provided over 605 of Haiti's exports. 1 in 5 jobs were lost.
>By 2015, most people displaced by earthquake had been re-housed.
109
Haiti - background
>LR = 48.7%
>GDP per capita = $1300
>80% of people live on $2 a day or less.
>Most business and services were located in the capital.
>Lies on Caribbean and North American plates. There was slippage along a conservative plate boundary that runs through Haiti.
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Haiti - short-term response
>$100 million in aid given by the USA and $330 million by the EU.
>810,000 people placed in aid camps.
>lack of immediate aid through poor planning, management and access meant that people had to try and rescue each other.
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Haiti -long-term response
>98% of the rubble on the roads hadn't been cleared restricting aid access.
>1 million people were still without houses after 1 year so still had to live in aid camps.
>Water and sanitation eventually supplied for 1.7 million people.
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Japan Earthquake, 2011 response
>Tohoku earthquake
>Many people had got outside during the earthquake and the response to the Earthquake was reasonably good.
>The warnings from the JMA also helped save lives.
>Many people didn't react quickly enough to the tsunami alert and even if they did, the 20 minutes or less warning was insufficient for the people to escape.
>The JMA and government did a good job of monitoring and getting a warning out to people, this probably saved lives.
>Over 340,000 displaced people in the region needed catering for and issues included shortages of food, water, shelter, medicine and fuel for survivors.
>The Japanese government responded by sending in specially trained people such as the Self-Defence Forces, a domestic response.
>Many countries, e.g. UK, sent search and rescue teams to help search for survivors.
>NGOs and other Aid agencies helped too, with the Japanese Red Cross $1 billion of donations.
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How can we limit earthquake damage?
1. Prediction
2. Plan
3. Protect
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How can we limit earthquake damage - prediction
>A tiltmeter can check any movements within the rock.
>Water levels can rise in wells and lakes because of cracks in the rocks.
>Animals can act strangely before the earthquake.
>Foreshocks before the main quake can be detected by a seismometer.
>Seismic 'gap' theory.
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Seismic 'gap' theory
>There are 2 'gaps' where no earthquakes have happened for many years.
>Pressure moves along.
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Building preparation and planning - developed country
1. Cross-bracing: to give added strength and prevent twisting.
2. Computer-controlled, movable roof weights: to counter the shock waves.
3. Automatic window shutters: to prevent falling glass.
4. Automatic sprinkler system and gas shut off to prevent fires.
5. Strengthened steel and reinforced concrete rod supports.
6. Rubber shock absorbers.
7. Base isolater: allows sideways motion.
8. Foundations set deep: into the ground.
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Preparing people - earthquake
>Earthquake drills.
>Emergency service practise rescuing people.
>Emergency kits - food, medicine, torch and radio.
>Text warning.
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Preparation in developing countries - buildings
>Building regulations in earthquake zones in developing countries.
1. Cross-braced wood or bamboo frame.
2. Lightweight thatch roof.
3. Walls made of mud and straw packed between wooden slats.
4. Simple steel rod foundations.
5. Concrete rings tie the walls to the foundations.
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Atmospheric Circulation - definition
>The large scale movement of air by which heat is distributed on the surface of the Earth.
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Emerging country - typhoon
>Typhoon Haiyan, Philippines.
>2nd November, 2013.
>Was the one of the strongest tropical cyclones on record which a was a category 5 on the Saffir-Simpson Scale.
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Typhoon Haiyan - preparation
>The Philippines was assisted with tracking the typhoon by Japan.
>The Government used the Public Storm Warning System (PSWS) to warn people across the country.
>Originally only a level 1 warning was given.
>Those that were in areas at risk of flooding or landslides (e.g. Samar and Leyte) were evacuated to safer areas.
>The military were ordered to send planes and helicopters to the region to help with the aid effort.
>5m high storm surges.
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Typhoon Haiyan - response
>7 provinces were placed under a 'state of national calamity'.
>The relief effort was slowed by blocked roads and damage to airports.
>Some areas were isolated for days.
>No sources of clean water available due to burst pipes and contamination.
>People in cities such as Tacloban needed evacuating as there was no electricity, clean water, food or shelter.
>However this could only happen during daylight hours.
>More aid went to Tacloban than any other areas meaning other areas felt abandoned.
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Vulnerability to cyclones
physical
social
economic
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Vulnerability to cyclones - physical
>Coastal areas are at a significant risk to hazards created by tropical cyclones as they form in oceans and seas.
>This does not mean inland areas don't suffer from the effects.
>Island nations such as the Maldives and the Philippines are more vulnerable as they are surrounded by warm water and have low relief.
>Therefore, they are more likely to suffer from flooding, storm surges and high wind speeds.
>However, areas of high relief are at risk of heavy rain and landslides.
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Vulnerability to cyclones - social
>Social inequality can make some areas more vulnerable.
>Areas with high poverty are more vulnerable as the houses and infrastructure will not be as stable, therefore it will be easily damaged or destroyed.
>The after-effects are also felt more in poorer regions as people may not have access to food, water and shelter or medical supplies.
>Therefore, more people are likely to suffer and die compared to people in more affluent areas.
>Areas with higher or lower average ages are more vulnerable.
>Older people and younger people are more likely to suffer an injury during disasters and have more difficult evacuating.
>The younger and old are also more vulnerable to catching illnesses and diseases as their immune systems are not as strong.
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Vulnerability to cyclones - economic
>Countries with higher levels of development are likely to have access to accurate weather prediction and monitoring systems so they can predict the tropical cyclones, landfall and evacuate people.
>They may also have more coastal defences meaning that storm surges pose less of a hazard.
>Affluent countries will also have well-established evacuation procedures and disaster response teams prepared for any impacts.
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tropical cyclones - what they need
>Need warm water to form, they also need the Coriolis effect for them to rotate hence, they are not located at the Equator. Also need:
- high humidity = there must be a lot of moisture in the atmosphere.
- rapid cooling = rising air must condense quickly to form the rainbands.
- low wind shear = if winds are blowing in different directions in the atmosphere a cyclone can't form/
- pre-existing low pressure = for the air to rise and generate a storm.
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ITCZ influence on tropical cyclones
>Main source are for tropical storms as the air rises and travels towards the poles in the Hadley cell.
>As what cyclone needs.
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When do cyclones dissipate?
1. Land
2. cold water
3. When it runs into another weather system where the wind is blowing in the opposite direction.
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ITCZ
Inter Tropical Convergence Zone
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Intensity of cyclones
>Powered by heat energy that is released as warm air condenses.
>The majority of this air is used to force air upwards into the atmosphere.
>Only a small amount is used to create a cyclone.
>Therefore, the warmer the water the more intense the storm.
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Seasonal distribution of cyclones
>June - Nov in Northern Hemisphere.
| >April - Nov in Southern Hemisphere.
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Convection currents
>The plates are continually moving on the asthenosphere due to rising hot currents called
convection currents in the mantle.
>Rock heated in the lower mantle by the core, rises slowly towards the crust.
>As it rises, it cools. When it reaches the asthenosphere it is forced sideways as it is blocked by the lithosphere above.
> It then sinks slowly towards the core and is
forced sideways due to the dense iron and nickel.
