Geography FA(80%) + CA1 ( 48%)

Hazard

Hazard is an event that causes a threat or damage to people, their surroundings and their properties.

Geological (natural )

Volcanoes

Earthquakes

Avalanches

Climatic (natural)

Tropical storm

Thunder storms

Droughts

Biological (natural)

Diseases

Pandemics

Pests

Technological

Climate change

Hazards in Cyprus

Droughts (not enough water)

Natural events that become hazards in indirect ways

If a volcano happens at a remote location (ocean ) away from cities and islands could trigger a tsunami or a big ash cloud.

Types of plate boundaries

Destructive

Constructive

Conservative

Collision zone (Fold mountain margin)

What determines the type of plate boundary ?

Direction

Destructive

1. Where Oceanic and continental crust are moving together

2. The denser oceanic crust sinks under the lighter continental crust

3. The oceanic crust is melted and directed under the friction , pressure and heat created by the surroundings

4. The melted molten rock might rise through the crust as hot magma leading to volcanic eruptions

5. If the friction and pressure is released it causes earthquakes.

6. (Nanzca plate- South American plate )

Constructive

1. Where plates move away from each other (normally under the ocean)

2. convection currents pull plates away from each other

3. Some cracks form between the plates and there is not solid crust

4. Magma rises through the gaps , reaching the surface where it causes volcanic eruptions

5. When lava cools down ,solid is formed (land / lithosphere )

6. (Pacific plate - Nanzca plate )

Conservative

1.Two plates slide past each other moving in the same direction , at different angles or speeds

2. due to their different speeds they tend to split or stay locked together building pressure

3. As one plate slips the pressure is released forming an earthquake

4. ( Pacific plate - North American plate)

Collision zone ( fold mountain margin)

1. Convection currents cause plates to collide with each other but as they have they same density none of them sinks , instead the ground is pushed upwards forming fold mountains

2. as continental crust gets compressed pressure builds up causing earthquakes

   (Eurasian plate - Into Australian plate )

   
   

Hotspot

A place on the Earth’s surface where is volcanic activity , but is not on a plate boundary . It is where hot magma rises to the earth’s surface to create basic volcanoes .

Earthquakes and their 3 scales

1. Richter scale

2. Mercalli scale

3. Moment Magnitude scale

Richter

Measures amount of energy released by the earthquake

Mercalli

Based on what people experienced and the amount of damage done

Moment magnitude

Best assessment for energy on the amount of rock movement (most common and accurate)

The magnitude of the earthquake on the Richter scale drops…

As the distance from the focus increases

Factors that show how big the damage could be

• Size of area affected

• Population density in that area

• How long event lasts

• If people are prepared or not

• Ability of country to deal with aftermath

• If people are warned in an advanced

Earthquake

A sudden and brief period of intense shaking of the ground caused by earthquake movement at plate boundaries

Primary earthquake impacts ( immediate effects )

• Downed power lines

• Collapsed buildings

• People killed

• Broken water , gas and sewage pipe lines

Secondary impacts

Tsunamis

Aftershocks

Fires due to gas pipes

Flooding

Trauma

Population decrease

Size of area affected

Greater damage

Density of population

More buildings are likely to collapse so more people affected

Depth of earthquake

More shallow damage

Education of what to do at an emergency

Fewer injuries

Planning of location of housing

Building away from earthquake areas to reduce damage

Strict anti seismic building codes

Most likely for buildings to survive earthquakes through the years

Earthquakes happen without warning

Caught people off guard so it increases damage

Level of economic development

Business afford to buy insurance and build earthquake resistant building

Why are impacts more severe in poor countries

• Low quality houses

• Infastructu Is bad , roads make it harder for vehicles to pass causing more deaths

• Not enough money to protect themselves

• Healthcare is worse , hospitals don’t have supplies causing people to die

Why people continue to live in those areas

• They’ve always lived there

• Employment

• Confident that the government will support them

• Confident that earthquakes will not happen again

Lava flow

Molten rock which can be thick , slow or runny . It can destroy farmland buildings and transport routes

Flood

Fast moving mudslide caused by ash mixed with rainwater or melted ice from the top of the volcano

Pyroclastic flow

SUPERHOT (700 degrees ) flow of she’s and volcanic rock at very fast speeds . They can drawn or bury anything in their path

Lahar

Large chunks of lava thrown out of the crater by the force of volcano

Volcanic bomb

When shot into the sky it can cause darkness , casuing distribution to air travel . Blankets crops roads and buildings can be collapsed .

Volcanic gas

When breathed it can cause health problems , breathing problems deaths . Can cause acid rain

Volcanic ash

Caused when hot ash or lava from a volcanic eruption rapidly melt snow at the summit of a volcano

Placement of each effect

Effusive eruptions

Occur along constructive plate boundary (magma rises through the gap)

Shield volcano

A gentle sloping volcano which thin and runny lava that flows quickly around the sides of the volcano

Primary impacts if volcanic eruptions

Lahars

Deaths and injuries

Destruction of buildings

Secondary impacts of volcanic eruptions

Trauma

fires

contaminated water

measuring explosiveness of a volcanic eruptions

VEI The Volcanic Explosivety Index

Measures the volume of erupted tephra (ash cloud ) (km3)

The height of the emotion cloud (km)

USED ONLY FOR EXPLOSIVE ERUPTIONS

Is a tropical cyclone an area if high or low pressure

Low

What part of the world tropical storms star

On either side of the equator (centre) between 5 and 20 degrees north and south

At what time tropical storms occur

Late summer

Tropical storms form over

warm oceans

Where temperature must be over

26 degrees

Suns energy

Condenses the sea water

Warmed ,moist air

Rises rapidly

Creating what kind of pressure ?

Low

The air moves away from where ?

The equator

Air starts to begin because of

Coriolis force

Coriolis force

A force cause by the earths rotation causing winds to deflect

Air by moving at different speeds and levels causes wind to

Shear

All the effects together create a

Vortex

Rising air cools until water vapour

Condenses

The condensed water vapour creates

Huge clouds (cumunoligous clouds ) and rain

Condensation releases energy to provide energy for

Hurricane

Winds move at least

120 km per hour

Hurricane travels towards

Poles

storms / hurricanes stop when

Reach colder areas or if it moved over land

Causes of tropical storms

• Warm and humid air

• Constant supply of energy from the sea ( that’s why it’s formed above warm seas)

• A Circulatory motion of the air that will shape the storm and make it spin

• Low wind shear (small changes of direction and speed )

How to measure tropical cyclones

Simpson hurricane scale

Short term impacts for tropical cyclones

• Damages property caused by heavy winds

• Destruction of business

• Form landslides , soil erosion ,flooding

Killing people

Tropical storm diagram

Diagram of composite volcano

Storm surge

Winds pick up water and push it towards shore which causes eroded beaches and damaged buildings ( above normal sea level)

Subduction

When two plates are moving towards each other . The edge of one plate margin is being destroyed as it plunges beneath the other plate