Hazards Flashcards
Natural Hazard-What?
A natural hazard is a natural event that is a potential threat to human life or property
Classification of Natural Hazards-Geophysical
A geophysical hazard is a hazard that is driven by the Earth’s own internal energy sources like Plate Tectonics
Classification of Natural Hazards-Atmospheric
Atmospheric hazards are driven by processes that are weather or climate related
Classification of Natural Hazards-Hydrological
A hydrological hazard is a hazard driven by water bodies, normally the ocean
Common Characteristics of Natural Hazards
- Dangerous affect to human life
- High in energy
- Has a rapid or short warning
- Has primary/secondary impacts
- Hazard causes people to adapt and mitigate
Impacts-Primary
Primary impacts are impacts that have an immediate effect on the area
Impacts-Secondary
Secondary impacts are the result of the primary impacts eg: Homelessness caused by destruction of buliding
The Dregg Disaster Model
According to this model, a disaster is when a hazard affects a vulnerable population
Factors that create a vulnerable population
- Lack of/Bad healthcare
- Bad preparation
- Young children
- Elderly Population
- Poor living conditions
- Steep slopes
- Lack of education
- Bad Water/ Lack of clean water
- Poor buliding quality
- Poor emergency services
- Less Income Country-Less money
Vulnerability-What
How susceptible a population is to the damage caused by a hazard
Perceptions of Hazards-Wealth
Richer people can move away from hazard affected areas, or build home to withstand hazards-Smaller risk for rich, High risk for Poor
Perception of Hazards-Religion
Some people adopt a fatalistic view towards hazards-Less risk for them
Perception of Hazards-Education
Those who are educated about the hazards have a better understanding of them, they can try to reduce the damage caused-Less risk for them
Perception of Hazards-Past Experience
Those who lived in hazard prone areas are more experienced-Less risk for them
Perception of Hazards-Personality
Some people do not fear them, they find them exciting-Less risk for them
Risk Perception-What
The subjective judgement that people make about the characteristics and severity of a risk
Risk-What?
The probability of a hazard event causing harmful consequences
Fatalism-What?
People accept that hazards are a natural occurrence. Loses are inevitable and people remain where they are. “God’s Will”
Adaption-What?
People see that they can prepare for the event so they will survive
Fear-What?
People feel so vulnerable to an event that they move away to areas with no hazards
Factors that increase risk perceptions
- No control over hazard
- Many deaths
- No understanding of Hazard
- Lack of awareness
- Large Scale
Factors that decrease Risk Perception
- Controllable Hazard
- Few deaths
- Understanding of Hazard
- Not being aware of hazard-“Ignorance is Bliss”
- Small scale impacts
- “It will never happen to me” attitude
Responses to a hazard
- Prevention of hazard or reduce the magnitude of the hazard
- Mitigation of the impacts of the hazard
- Government intervention
- Do nothing-Fatalism
The Hazard Management Cycle
Once a hazard happens, the authorities respond to it. Then, the area is reconstructed. Mitigation, which reduces the severity of the hazard is next, which increases the areas preparedness for a disaster. Then, a disaster strikes and the cycle begins again
The Hazard Management Cycle-Mitigation
Actions aimed at reducing the severity of an event and lessening the impacts. Examples of mitigation are: buliding earthquake proof bulidings or educating people on what to do during a hazard. Mitigation can occur before or after the hazard event
The Hazard Mangement Cycle-Preparedness
Planning what to do during a hazard and how to respond to it. Examples:Warning systems, a risk management plan
The Hazard Mangement Cycle-Response
How people react during and immediately after the hazard event. Examples include hiding in a safe place, rescuing people who are trapped
The Hazard Management Cycle-Recovery
Getting the area back to a state of normality. Examples include: Rebuilding houses and restoring the key services in the area
The Hazard Mangement Cycle-Why a cycle?
It is a cycle as hazard events keep happening. Preparation and mitigation is a constant process
The Park Model-Pre Disaster
Before the hazard event, all is normal
The Park Model-Disruption
During and directly after the event, there is destruction of property and loss of life, before the people begin to respond
The Park Model-Relief
The immediate local and possibly global response in the form of aid,expertise and search and rescue
The Park Model-Rehabilitation
The resolving of longer term problems, including temporary housing solutions and the restoration of services
The Park Model-Reconstruction
The rebuilding of permanent houses and infrastructure
The Park Model-Reconstruction-Same
If buildings are the same as they were pre event, the area returns to normal
The Park Model-Reconstruction-Higher
If the buildings are to an improved standard than pre event, the area improves and the vulnerability to hazards decrease
Plate Tectonics-Core
The area of the centre of the Earth. It is the hottest part and is divided into the inner core and the outer core
Plate Tectonics-Core-Inner Core
A solid ball that is 1300KM thick and has a temperature of 7200degrees Celsius. It is made of iron and nickel
Plate Tectonics-Core-Outer Core
A semi molten area that is 2200KM thick. It contains lots of iron and nickel
Plate Tectonics-Mantle
The mantel is above the core, and is made out of silicate rocks.
Plate Tectonics-Crust
The outer layer of the Earth. There are two types of crust
Plate Tectonics-Types of Crust-Continental
The thicker and less dense type of crust
Plate Tectonics-Types of Crust-Oceanic
The thinner and more dense type of crust
Plate Tectonics-Spheres-Lithosphere
This sphere consists of the crust and the upper part of the mantle
Plate Tectonics-Spheres-Astenosphere
A plastic layer below the lithosphere. The tectonic plates float on the lithosphere
Plate Tectonics-Spheres-Mesosphere
The remaining part of the mantle which connects to the crust
Plate Tectonics-Moho
The line dividing the upper and lower mantle levels
Movement of Tectonic Plates-Convection Currents
The mantle is hottest close to the core, so lower parts of the asthenosphere warm up,become less dense, and rise. As they get to the top of the asthenosphere, they cool down and sink. These movements are convection currents. They create drag on the base of the plate, causing them to move
Movement of Tectonic Plates-Slab Pull
At a destructive plate margin,the denser crust is forced under the less dense crust. The sinking of the plate edges pull the rest of the plate,causing it to move
Movement of tectonic plates-Ridge Push
At constructive plate margins,magma rises to the surface and creates new crust with a slope. The crust cools and becomes denser,with causes the plates to move apart due to pressure. This process is also known as gravitational sliding
Movement of Tectonic Plates-Sea Floor Spreading
As tectonic plates move apart,magma rises to fill the gap, cools and creates new crust. This new crust is dragged apart and more crust is formed between it. This causes the sea floor to get wider
Plate Boundaries-Constructive
A constructive boundary is when two plates seperate
Plate Boundaries-Destructive
Causes when two plates collide with each other
Plate Boundaries-Landforms-Constructive-Mid Ocean Ridge
A mid ocean ridge is caused by sea floor spreading. Mid ocean ridges can also create transform faults,which cut across the ridges and occur a right angles to the plate boundary. Volcanic eruptions along the fault can create submarine volcanos,which can grow to above sea levels
Plate Boundaries-Landforms-Constructive-Rift Valley
Formed when the lithosphere stretches,causing parallel faults. The land between the faults collapses into deep wide valleys,separated blocks of land called Horsts. Example:Great African Rift Valley
Plate Boundaries-Landforms-Destructive-Oceanic and Continental-Deep Ocean Trench
The oceanic plates subducts under the continental plate as it is denser. The point of collision is when the oceanic plate bends and forms a deep ocean trench.
Plate Boundaries-Landforms-Destructive-Oceanic and Continental-Fold Mountains
The continental plate is uplifting,compressed,buckled and folded to create fold mountains eg:The Andes
Plate Boundaries-Landforms-Destructive-Oceanic and Continental-Magma Creation
The decending oceanic plate starts to melt in the Benioff Zone. This process causes magma to be created
Plate Boundaries-Landforms-Destructive-Oceanic and Oceanic-Deep Ocean Trench
When two organic plate collide, the faster or denser plate subducts beneath the other. This creates a deep ocean trench
Plate Boundaries-Landforms-Destructive-Oceanic and Oceanic-Island Arcs
The collision of plate also causes melting at the benioff zone. This magma rises to create submarine volcanoes, which can grow into island arcs
Plate Boundaries-Landforms-Destructive-Continental and Continental-Fold Mountains
The collision of the plates does not cause subduction. The plates become uplifted and buckled to form fold mountains
Plate Boundaries-Landforms-Conservative
There are no landforms formed on conservative plate boundaries
Magma plumes-What?
A magma plume is a vertical column of extra hot magma that rises up from the mantle
Magma Plumes and the formation of Volcanoes
Volcanoes form above magma plumes. The magma plume remains stationary,the crust moves above it. Volcanoes form in the part of the crust that is above the plume. As the crusts move, a chain of volcanoes is formed,like the volcanic islands of Hawaii
Volcanoes-Viscosity
The thickness of lava
Volcanos-Types of Lava-Basalt
Lava that has 48%-52% viscosity
Volcanoes-Types of Lava-Andesite
Lava that has 52%-63% viscosity
Volcanoes-Types of Lava-Dacite
Lava that has 63%-68% viscosity
Volcanoes-Types of Lava-Rhyolite
Lava that has 68%-77% viscosity
Why is rhyolite lava the deadliest
It sticks to the top of the volcano and builds up pressure and eventually erupts at a high magnitude
Types of Volcanoes-Fissure
Have very liquid lava flows,wide spread, lava is emitted from fractures. Example:River Plateau in Colombia
Types of Volcanoes-Shield
Liquid lava is emitted from central vent. Large in size. Example:Hawaiian Volcanoes
Types of Volcanoes-Cinder Cone
Explosive liquid lava,small, emitted from a central valve. Can become shield volcano. Example:Mount Taylor
Types of Volcanoes-Composite
More viscous lava emitted from a central vent. Example:Mount St Helens
Types of Volcanoes-Volcanic Dome
Very viscous lava,commonly occurs adjacent to craters of composite volcanoes. Example:Mount Lassen
Types of Volcanoes-Caldera
Very large composite volcanoes that collapsed after a explosive period. Example:Yellowstone
Location of Volcanoes
Most volcanoes occur near constructive and destructive plate margins. A small number are formed near magma plumes
Volcanic Eruptions-Constructive Boundaries
Basalt lava is formed here. Eruptions are frequent and long lasting,but not violent. If
Volcanic Eruptions-Destructive Boundaries
Andesitic and rhyolitic lava is formed here. Eruptions are intermittent and short,but violent as viscous lava blocks vents,causes pressure to build, which can be reduced by a violent eruption
Volcanoes-Magnitude
Volcanic events range is size. Magnitude is measured using the Volcanic Explosively Index, which grades companies based on the amount of material ejected and how high the material is blasted
Volcanoes-Frequency
How often an eruption occurs. Less frequent eruptions are normally larger in magnitude
Volcanoes-Randomness vs Regularly
Some erupt at regular intervals, while others erupt at random intervals
What determines eruption type-Crystals
Crystals in magma makes it more viscous. Highly crystallized magma means it is more likely to explode
What determines eruption type-Gases
If gas cannot escape highly viscous magma, it creates explosions
What determines eruption type-Temperature
Low temperature magma flows easily and is more likely to erupt explosively
Types of Eruption-Hawaiian
Basatic lava flows gently from a central vent
Types of eruption-Icelandic
Basaltic lava flows gently from fissures
Types of Eruption-Strombolian
Thicker basaltic lava occasionally flows. Frequent explosive eruptions of tephra and steam
Type of Eruptions-Vulcanian
Thicker basltic,andestic and rhyolitic lava flows. Less frequent but violent eruptions of gas,ash and tephra
Types of Eruptions-Vesuvian
Thick basaltic,andesitic and rhyolitic lava flows. Very violent gas explosions blast ash high into the sky, following long period of inactivity
Types of Eruptions-Peléean
Andesitic and rhyolitic lava flows. Very violent eruptions of nuées ardentes
Types of Eruptions-Plinian
Rhyolitic lava flows. Exceptionally violent eruptions of gas,ash and pumice. Torrential rainstorms causes devastating lahars
Volcanic Hazards-Pyroclastic Flow
A mixture of super heated gas,ash and volcanic rock that flows down the side of the volcano. It travels quickly,can can cause widespread death and destruction
Volcanic Hazards-Lava Flows
Lava flow from a vent down the side of the volcano. Speed and distance travelled depends of viscosity. Low viscosity lava can travel faster than high viscosity. Lava flows destroy everything in their path, but as they are slow,allow time for people to evacuate
Volcanic Hazards-Volcanic Gases
Lava contains carbon dioxide and sulfur dioxide which go into the atmosphere during a eruption. These gases can be harmful to life
Volcanic Hazards-Tephra
Material that has been ejected from the volcano. Materials can be of many sizes and can travel thousand of kilometres from the volcano. Large pieces can damage buildings and kill people,smaller pieces can damage vegetation
Volcanic Hazards-Lahars
A mixture of volcanic material and water mixes. These flow very quickly and travel far. Lahars can bury or destroy habitats,and buildings
Volcanic Hazards-Acid Rain
The reaction of volcanic gases and water vapour from the atmosphere. This falls as acid rain. This can damage ecosystems and cause stone and metal to deteriorate
Volcanic Hazards-Social Impacts
- People killed
- Buildings and infrastructure destroyed
- Fires from pyroclastic and lava flows destroy buildings
- Deaths by mudflow and flooding
Volcanic Hazards-Environmental Impacts
- Destruction of ecosystems
- Acidification of aquatic ecosystems
- Acid rain removes nutrients from soil
- Enhanced Greenhouse Effect and Global Warming
- Reduction of Earths temperature
Volcanic Hazards-Economic Impacts
- Business destroyed-No jobs
- Expensive to repair buliding damage
- Eruption can create a form of tourism
Volcanic Hazards-Political Impacts
- Agriculture damage causes food shortages-Creates unrest
- Government spends money on repairing buliding rather than improving services-Slows down development
Prediction of Volcanic Eruptions-Monitoring-Seismic Activity
Microquakes indicate rising magma cracking overlaying rocks
Prediction of Volcanic Eruptions-Monitoring-Ground Deformations
Bulging of ground caused by rising magma
Prediction of Volcanic Eruptions-Monitoring-Upwards movement of iron rich magma
Changing magnetism means magma levels or rising
Prediction of Volcanic Eruptions-Monitoring-Rising water and ground temperature
An increase in water and ground temperature means magma is rising
Prediction of Volcanic Eruptions-Monitoring-Case Study Location
Iceland
Prevention of Volcanic Eruptions
You cannot prevent a eruption. However, it is possible to prevent eruptions causing a risk for people like preventing surrounding land from being built on
Preparing for a volcanic eruption
- Install monitoring systems to predict a eruption
- Authorities to cordon off areas affected by volcano if eruption is imminent
- Individual Preparedness-First aid kit
- Communities lead search and rescue services
- Drills
Adapting to a Volcanic Eruption
- Strengthen buildings to reduce the risk of collapse
- Living by a volcano gives fertile land and a cheap source of geothermal energy
Preparing for a Volcanic Eruption-Case Study-Vesuvius
- Put trees on banks
- Developed hazard maps
- Harmonic Tremmer-Low frequency means more magma
- Evacuation Plan-Uses tram, 80 ships and 16000 people will assist with the evacuation
Volcano Case study-Montserrat-Causes
Destructive plate boundary on a island arc. The south American oceanic plate subducted beneath the Caribbean continental plate. This created the Chances Peak volcano which erupted
Volcano Case study-Montserrat-Hazards
- Volcanic ash
- Dust
- Pyroclastic flow
- Andesitic Flow
Volcano Case study-Montserrat-Primary Impacts
- South of island was covered in ash
- 2/3 of all ones were flattened
- Airport and Infrastructure was completely destroyed
Volcano Case study-Montserrat-Secondary Impacts
- Fires from pyroclastic flow killed 19 people
- Homelessness
- Businesses destroyed
- Less aid arrived
Volcano Case study-Montserrat-Responses-Short Term
- Montserrat volcano Observatory was set up
- South of island became a exclusion zone
- NGO’s set up temporary schools and provided medical support
- Warning System set up
- UK and US Navy troops came to aid evacuation process
- £17 million of UK aid paid from temporary housing and water purification system
Volcano Case study-Montserrat-Responses-Long Term
- 3 year redevelopment plan was funded by UK
- Monserrateians were given British citizenship-Move if they wanted
- 2005-many people moved back-South part remained an exclusion zone
- Vegetation is slowly regrowing due to fertile land
- Warning system is tested daily at midday
- Rebuilding as a tourist destination with volcano as a attraction
- UK have paided over £420 million in aid
Volcano Case Study-Nevada Del Ruiz-Causes
A destructive plate boundary. The Nazca plate subducted under the south American continental plate
Volcano Case Study-Nevada Del Ruiz-Hazards
- Plinian eruptions
- Pyroclastic flow
- Lahars
- Tephra
- Volcanic Ash
- Andestic and Dacitic lava
Volcano Case Study-Nevada Del Ruiz-Impacts-Primary
- 23000 dead
- 85% of Amero was destroyed
- 35 million tonnes of material erupted
- Lahars
- Pyroclastic Flow
- Infrastructure destroyed
Volcano Case Study-Nevada Del Ruiz-Impacts-Secondary
- 8000 were made homelessness
- Agriculture and Businesses damaged
- No jobs
- Roads blocked-No aid
- People stuck in Lahars
- Diseases spread
Volcano Case Study-Nevada Del Ruiz-Responses-Short Term
- After 3 days,government did not know what to do
- Health workers vaccinated the diseased
- Rescuers were delayed due to damaged
- Army burnt bodies and killed animals to prevent disease
- Aid was not given quickly-Lack of helicopters
- NGO’s gave aid
Volcano Case Study-Nevada Del Ruiz-Responses-Long Term
- Warning systems established
- Evacuation plans made
- Volcano drills
- Public education about volcanoes
- Hazard maps made
Volcano Case Study-Nevada Del Ruiz-Why was it so bad?
Residents did not take the warning seriously, meaning that they were not prepared. Helicopters went to the highest bidder, not those who needed it
Human Responses to a eruption-Case Study-Mount Etna
To prevent damage being caused, the authorities have used a range of methods to prevent or limit the damage caused by the eruption of Mount Etna
Human Responses to a eruption-Case Study-Mount Etna-Methods Used
- Earthworks to redirect lava from important areas
- Earth dam build-Holds lava
- Blocks dropped into lava to plug it
- Explosives used to divert lava into new channels
- Closure of Catania Airport
Earthquakes-How
Earthquakes are caused by the tension that builds up at the plate boundaries. When the plates jerk past each other, it sends out shockwaves. These are earthquakes
Focus-What?
The point where the earthquake occurs
Epicentre-What?
The point on the surface exactly above the focus
Seismic Shockwaves-What?
The waves of energy released as the rock jolts apart. These begin at the focus and spread outwards
Earthquake Formation-Constructive Boundary
The plates move away from each other, creating faults. These can widen and lead to frictional stress building up. A shallow earthquake occurs to release this pressure
Earthquake Formation-Destructive Boundary
Oceanic plate subducts under continental plate and melts in the benioff zone,due to heat and friction. Pressure builds and is released as a medium or deep focus earthquake
Earthquake Formation-Conservative Boundary
Friction from the plates sliding past each other build up. The pressure can be released as a powerful shallow focus earthquake
Earthquake Formation-Collision Boundary
Pressure can build up during the formation of mountains. Released as shallow focused earthquake
Earthquakes-Magnitude and Frequency
Low magnitude earthquakes happen daily. Very high magnitude earthquakes are less frequent
Earthquakes-Randomness
Earthquakes are random when they occur. They occur on or near plate boundaries only
Earthquakes-Predictability
Scientists can monitor the tectonic plates to see which areas are at risk. They cannot predict when or the magnitude
Factors that affect Earthquakes-Boundary type
High magnitude earthquakes occur on destructive boundaries. Low magnitude earthquakes occur on conservative boundaries
Factors that affect Earthquakes-Depth of Focus
Deep focus gives high frequency earthquakes but cause less damage. Shallow focus earthquakes cause more damage-Waves have travelled less distance
Types of Seismic Waves-P Waves
The fastest and reach surface first. They travel like sound waves, through the mantle and core to the opposite side of the earth
Types of Seismic Waves-S Waves
Travel half as fast as S waves. They travel like a skipping rope. They can travel though the mantle but not the core
Types of Seismic Waves-Love Waves
These waves are the slowest and cause the most damage
Types of Seismic Waves-Rayleigh Waves
These waves radiate from the epicentre in low frequency rolling motions
Earthquakes-Social Impacts
- Buildings collapse, people are killed,injured or made homeless
- Gas and power lines break-Fires that kill
- Water pipes break-Flooding
- Diseases spread due to lack of clean water
Earthquakes-Environmental Impacts
- Chemical can damage environment due to destruction of power plants
- Fires can destroy ecosystem
Earthquakes-Economic Impacts
- Destroys business premises-No jobs-Damages regional economy
- Country may have to rely on expensive imports
- Building and Infrastructure damage is expensive to repair
Earthquakes-Political Impacts
- Food,water and energy shortages causes unrest
- Country might need to borrow money-Creates debt
- Money that would have been used for development is used for repairs
Preventing a Earthquake
You cannot prevent a earthquake from happening,but you can prevent it causing damage example:prevention of building houses on ground prone to liquefaction
Preparing for a Earthquake
- Earthquake Warning System
- Earthquake plans
- Community lead search and rescue teams
Adapting to Earthquakes
-Retrofitting buildings-Make them able to withstand a Earthquake
Earthquake Case Study-Haiti-Cause
The North American plate and the Caribbean plate have a conservative plate boundary. They rub together and create friction, then get stuck. This builds up pressure that is released as a Earthquake
Earthquake Case Study-Haiti-Impacts-Primary
- Port-Au-Prince was flattened
- 230000 dead
- 50% of poorly built building made of concrete collapsed including police station
- 180000 homes destroyed
- 5000 schools damaged or destroyed
- Liquefaction caused building foundations to subside
- Infrastructure was severely destroyed
Earthquake Case Study-Haiti-Impacts-Secondary
- Strong aftershocks-6.1 magnitude earthquake
- Government was crippled
- Port Au Prince became lawless due to no police
- After 1 year-Cholera killed over 1500, 1.5 million were homeless
Earthquake Case Study-Haiti-Responses-Short Term
- International search teams struggled in the dense environment
- Local people helped to look for survivors
- US Military took control of airport to speed up aid distribution and reopened the pier
- 16000 UN troops restored law and order
- UN provided basic food necessities-Farmers were supported
- NGO’s provided bottled water and water purification tablets
- Emergency surgeries were set up to perform life saving operations
- 3000 latrines built
- Homeless were placed in emergency camps
Earthquake Case Study-Haiti-Responses-Long Term
- $11.5 billion reconstruction project to be completed in 2020
- Farming sector was reformed-Encourages Self Sufficiency
- Rebuilding of buildings
- Slums were demolished-High risk area
- Affordable New homes
- Economic activities moved from Port Au Prince
- UN strategy developed-creates jobs in clothing manufacturing,tourism and agriculture, reduced uncontrolled urbanization
Earthquake Case Study-Haiti-Why were people vulnerable
- Very shallow focus
- Epicentre close to Port Au Prince
- Poor building quality
- Buildings built on top of buildings
- Haiti is a LEDC
- Crowded housing areas
- 1/2 lived in poverty
- 2/5 were unemployed
Tsunamis-What
Tsunamis are a primary impact of a Earthquake
Tsunami-Formation
First, a earthquake is created on a destructive plate boundary. The fault then ruptures and the sea bed thrusts upwards. This causes giant ripples. The tide then goes out,water forms trough of wave. Shallow water dies, the back of wave is traveling fast, when it reaches the front, a vertical wall of water is formed
Ways to Plan,Predict and Prepare for a Tsunami
- Warning System
- Monitor seismic activity
- Education
- Drills
- Zoning at risk areas-Not developing in high risk areas
- Leaving natural protection
- Planting New natural protection
- Moving villages inland
- Hard engineering around major cities
- Homes on stilts
Tsunami Case Study-Indian Ocean- Impacts-Primary
- 300000 died,thousands of undiscovered bodies
- Removal of vegetation and top soil
- Destruction of Infrastructure
- Destruction of Coastal settlement-Banda Aceh was destroyed
Tsunami Case Study-Indian Ocean- Impacts-Secondary
- Widespread homelessness
- Fishing,Agriculture and tourism sectors destroyed
- Contaminated water and soil
- Increase in gap between rich and poor
Tsunami Case Study-Indian Ocean- Responses-Short Term
- Massive international relief efforts
- Foreign military troops provided assistance
Tsunami Case Study-Indian Ocean- Responses-Long term
- Large scale reconstruction program
- Aid distribution was delayed due to political barriers
- Government prejudices were highlighted-lower class was ignored in India
- Tourist resorts were quickly rebuilt, locals were forced out
- Tsunami Warning System set up
- Education and Drills
- Hazard mapped coastal zones
Earthquake and Tsunami Case Study-Japan-Cause
The Pacific Plate subducts under North American Plate. The Pacific plate suddenly slipped upwards. This caused a earthquake followed by a Tsunami
Earthquake and Tsunami Case Study-Japan-Impacts-Primary
- Buildings collapsed
- Complete destruction caused by tsunami
- 5000 KM² of flooding
- Cities were ruined-Transport links destroyed
- Oil refinery went up in flames
- 17000 died in Sendai area
- 18000 dead or missing due to tsunami
Earthquake and Tsunami Case Study-Japan-Impacts-Secondary
- Half a million homeless
- Over a million without water, over 6 million homes without electricity
- Food,Water,petrol and medicinal supplies shortages
- 700 aftershocks
- Explosions at Fukushima Nuclear Power Plant
Earthquake and Tsunami Case Study-Japan-Responses-Short Term
- Survivors lived in camps
- Rescue Missions
- 100000 soldiers sent to establish order and distribute supplies
- International Aid given
- Exclusion zone around Power plant
- Shut down of all Japanese Nuclear power plants
Earthquake and Tsunami Case Study-Japan-Responses-Long Term
- Unveiled new tsunami warning system in 2013
- Government set up zones to encourage rapid rebuilding
- 2016-Nuclear Power Plants restart
- 100000 residents of Fukushima have not returned home
- Radioactive rubble still awaiting permanent disposal as no prefecture accepted it
- $300 billion was the total cost of the hazard
Tropical Storms-Formation
A cluster of thunderstorms form over a warm ocean . Moisture rises to create clouds. A vertical column hot air rises and begins to spin,AKA the Corvallis effect. The eye is formed, followed by the eyewall. The storm then hits land, and loses energy
Tropical Storms-The eye
The centre of the storm
Tropical Storms-The Eyewall
A area below the eye of towering rainfalls with rising hot air
Tropical Storms-Locations
All tropical storms form between the tropics of cancer and Capricorn
Factors that affect the distribution of Tropical Storms-Oceans
Tropical storms form in oceans as they are formed by moisture and energy from the sea
Factors that affect the distribution of Tropical Storms-Temperature
The sea temperature needs to be more than 26°C for tropical storms to form
Factors that affect the distribution of Tropical Storms-Atmospheric Instability
Tropical storms form in regions of intense atmospheric instability where warm air is forced to rise
Factors that affect the distribution of Tropical Storms-Rotation of Earth
A certain amount of spin is needed to cause the Corvallis effect. This spin increases as you get further from the equator.
Tropical Storms-Hazards-Strong Winds-Characteristics
Wind speeds in excess of 120KpH,stronger winds occur at eyewall
Tropical Storms-Hazards-Strong Winds-Primary Effects
- Tearing off roofs
- Damaging power lines
Tropical Storms-Hazards-Strong Winds-Secondary Effects
- Debris can cause transport disruption
- Widespread power outages
- Fires
Tropical Storms-Hazards-Storm Surges-Characteristics
A huge surge of water sweeps inland from the sea and floods low lying areas
Tropical Storms-Hazards-Storm Surges-Causes
A combination of low atmospheric pressure of the tropical storm and powerful winds
Tropical Storms-Hazards-Storm Surges-Primary Effect
- Loss of life
- Flooding of agriculture land
- Polluted freshwater supplies
- Housing destroyed
- Coastal erosion
Tropical Storms-Hazards-Storm Surges-Secondary Effect
-Diseases spread
Tropical Storms-Hazards-Coastal and River Flooding-Characteristics
An excess of 200metres of rainfall in just a few hours can lead to flooding
Tropical Storms-Hazards-Coastal and River Flooding-Primary Effects
- Urban flash flooding
- Rise in river levels
- Overwhelmed drains
Tropical Storms-Hazards-Coastal and River Flooding-Secondary effects
-Houses,Infrastructure and land destroyed
Tropical Storms-Hazards-Landslides-Formation
Intense rainfall increases the hydrostatic pressure within a slop. This weakens the slop and it collapses
Tropical Storms-Hazards-Landslides-Primary Effects
- Houses,Infrastructure and land destroyed
- Can trigger Earthquakes
Tropical Storms-Frequency
As global temperatures rise,frequency increases. This could be due to an increase in monitoring
Tropical Storms-Magnitude
In theory,if sea temperature rises, magnitude increases
Tropical Storms-Regularity
They will always occur in a season. For example:US hurricane season is August-October
Tropical Storms-Predictability
Can be predicted to an extent by looking at weather patterns. Only hit certain areas due to location of formation
Tropical Storms-Measurement
They are measured on the Saffir-Simpson scale. It measures windspeed, but does not take into account the impacts caused by the tropical storm
The Saffir-Simpson Scale-Tropical Depression
Wind speed-0-38 mph
Storm Surge-None
The Saffir-Simpson Scale-Tropical Storm
Wind speed-39-73 mph
Storm Surge-0-3ft
The Saffir-Simpson Scale-Category One
Wind speed-74-95mph
Storm Surge-4-5ft
The Saffir-Simpson Scale-Category Two
Wind Speed-96-110mph
Storm Surge-6-8ft
The Saffir-Simpson Scale-Category Three
Wind Speed-111-130 mph
Storm surge 9-12ft
The Saffir-Simpson Scale-Category Four
Wind Speed-131-155mph
Storm surge-13-18ft
The Saffir-Simpson Scale-Category Five
Wind speed >156 mph
Storm Surge->18 ft
Tropical Storms-Impacts-Social
- People may drown, be injured or killed
- Destroyed Homes
- Damaged electricity cables
- Sewage outflows-Contaminated water
- Diseases spread due to lack of clean water
- Food shortages-Farmland damaged
Tropical Storms-Impacts-Political
- Unrest and conflict
- Money that would have been used for development is used for repairs
Tropical Storms-Impacts-Economic
- Repairs cost a lot of money
- Due to damage,businesses can’t trade
- Due to damage to agricultural land, commercial farming is destroyed
Tropical Storms-Impacts-Environmental
- Eroded beaches
- Coastal habitats destroyed
- Polluted environment
- Landslides block watercourses,changing their course
Prevention of a tropical storm
You cannot prevent it from it happening,but you can prevent damage from occurring
Preparing for a Tropical Storm-Methods
- Education
- Minor structure improvements
- Preparing emergency supplies
- Plan evacuation routes
- Use models to track hurricanes
Adapting to a tropical storm-Methods
- Land zoning-low value land at coast
- Properties on stilts
- Storm surge elevation markers
- Retrofitting of buildings
Adapting to a tropical storm-Case Study-Darwin
- Mandatory wind resistant building structures
- Regular building inspections
- Regular building maintenance
Adapting to a tropical storm-Case Study-Bangladesh
-Has monitoring centre
Multi use concrete cyclone shelters
-Buildings on stilts
Tropical Storms Case Study-Hurricane Katrina-Primary Impacts
- Communication infrastructure damaged
- Major roads in/out of New Orleans were damaged
- Levees and floodwalls breached
- 80% of New Orleans underwater
- Extensive building damage
- Damage to forestry
- 1464 died
Tropical Storms Case Study-Hurricane Katrina-Secondary Impacts
- 1.7 million without electricity
- Nearly everyone became unemployed-no taxes collected
- Oil production effected-Petrol prices rose
- A Million made homeless
- Evacuated residents were spread across the country, many went to Houston
- Looting and Civil disturbances became a serious problem
Tropical Storms Case Study-Hurricane Katrina-Short Term Responses
- People prepared for it
- Mandatory evacuation-not efficient as 21% had no transport
- Sandbags and boarded up windows
- Insurance payouts
- Evacuated to the Superdome-aid went there
- National Guard handed out aid
- Helicopters helped evacuation
Tropical Storms Case Study-Hurricane Katrina-Long Term Responses
- New education system
- New healthcare system
- Raised the height of Levees
- Flood wall built
- Improved pumps
- Built a 2 mile wall
- Making wetlands
- Built floodgates
- Hurricane preparedness week
- Rebuilt some homes
Tropical Storms Case Study-Hurricane Katrina-Why was New Orleans vulnerable
- By the gulf of Mexico
- Just above the tropic of Cancer
- Lake to north of city
- It’s flat
- Below sea level
- Wetlands to the south of Louisiana
- Low flood wall
- Short and weak levees
Tropical Storms Case Study-Cyclone Nargis-Primary Effects
- 140000 died
- Destroyed power and water supplies
- Damaged homes
- Huge storm surge
Tropical Storms Case Study-Cyclone Nargis-Secondary Effects
- Homelessness
- Businesses destroyed
- No communication network
- No clean water
- Contaminated wells
- Diseases spread
- No food-crops destroyed
- Rice famine
Tropical Storms Case Study-Cyclone Nargis-Short Term Responses
- Military restored basic services
- Basic aid given by Bangladesh and India
Tropical Storms Case Study-Cyclone Nargis-Long Term Responses
- Camps set up
- Aid was rejected
- Myanmar still does not have a adequate warning system
Wildfires-What
An uncontrollable fire
Wildfires-Types-Ground Fire
Where the ground burns. It is a slow smouldering fire with no flame and little smoke
Wildfires-Types-Surface Fire
Where leaf litter and low lying vegetation burns
Wildfire-Types-Crown Fire
The fire moves rapidly through the canopy. Fires are intense and fast moving
Wildfires-Causes-Physical
- Lightning
- Drought conditions
- Extreme heat
- Dry vegetation
- Spontaneous Combustion
- Volcanic lava/ash
Wildfires-Causes-Human
- Arson
- Campfires
- Cigarettes
- Broken glass
- Barbeques
- Matches
- Collapse of Power Lines
The Fire Triangle-What
3 elements that are needed to create a wildfire
The Fire Triangle-Elements
- A source of fuel
- Oxygen
- Heat
Optimum Conditions for a wildfire-Vegetation
- Thick undergrowth or closely spaced trees
- Trees that contain a lot of oil
Optimum Conditions for a wildfire-Fuel
- Fine dry material
- Large amount-Continuous cover
Optimum Conditions for a wildfire-Climate
- Has dry season and wet season
- Strong winds-provides oxygen
Wildfires-Impacts-Environmental-Primary
- Destruction of habitats and ecosystems
- Animals die-impacts food chain
- Increase of carbon dioxide in atmosphere
- Atmospheric pollution
Wildfires-Impacts-Environmental-Secondary
- Lack of trees-decrease of nutrients,increase in flooding risk
- Greenhouse effect strengthen
- Climate change
Wildfires-Impacts-Social-Primary
- Loss of life
- Temporary displacement
- Disruption to power supplies
- Communication services damaged
Wildfires-Impacts-Social-Secondary
- Possible need for New employment
- People may need to obey rules and regulations towards forest areas
Wildfires-Impacts-Economic-Primary
- Damage to buildings and services
- Financial loss
- Businesses lost
- Loss of crops and livestock
Wildfires-Impacts-Economic-Secondary
- Rebuilding and relocation cost
- Replacement of farm infrastructure and livestock
- Cost of future preparedness and mitigation strategies
Wildfires-Impacts-Political-Primary
- Actions of emergency services
- State of emergency declared
- Pressure on authorities to prioritize responses to the wildfire
Wildfires-Impacts-Political-Secondary
- Develop strategies for preparedness and mitigation
- Review laws about the leisure use of the countryside
Techniques to reduce damage of wildfires-Air Drops
- Used in rural areas
- A plane drops water
- Puts out spot fires
Techniques to reduce damage of wildfires-Air drops of flame retardant material
- Dropped from plane
- Prevents part of area from being burned
Techniques to reduce damage of wildfires-Back Fire
- Controlled preburning of area
- Burning of dry vegetation
- Should stop fire-no fuel
- Men who are parachuted in, burn the area to prevent fire spreading
Techniques to reduce damage of wildfires-Fire Breaks
- A gap in the forest,prevents fire spreading
- Doesn’t stop flying embers
Prevention of Wildfires
They can be prevented by:
- Controlled burning of fuel
- Public awareness campaigns
- Fire bans during high risk times
Preparation for a wildfire-Methods
- Early detection
- Volunteer fire service in rural areas
- Weather warnings
- Fire proof homes
Fire proof houses
- Made of non combustible materials
- Concrete flooring
- Sealed windows
- Shades to prevent embers coming in
- All shrubbery removed
- A defensible space around house
- Removal of anything that could burn
- Lawns are wet
Wildfires-Mitigation techniques
- Satellites to detect fires
- Drones to survey wast areas
- Removal of fuel
- Natural barriers-Eg:Rivers
- Disaster aid
- Fire Insurance
Adapting to Wildfires
- They can help and hinder environment
- Planning regulations-Can’t develop at risk areas
- Building Design-Simple,cheap,made of non polluting materials
- You choose to live there
Wildfires-Case study-Victoria,Australia-Causes
- Very strong winds in multiple directions
- Hottest day on record
- Very dry vegetation
Wildfires-Case study-Victoria,Australia-Impacts
- Houses and businesses destroyed
- 450000 hectares of land destroyed
- Spot fires put Melbourne’s power lines at risk
- Bunyip forest burned
- Crops lost
- Trains stopped
- 173 killed
- Over 400 injured
Wildfires-Case study-Victoria,Australia-Responses
- Water dropped by helicopters
- Spraying house with water
- 20000 fire fighters deployed
- People evacuated
- More than AUS$400 million was donated to help rebuild homes
Multi Hazardous Environment Case Study-The Philippines-Volcanoes
The Philippines is near a destructive plate boundary. The Philippine plate subducts under the Eurasian plate
Multi Hazardous Environment Case Study-The Philippines–Volcanoes-Example
Mount Pinatubo erupted in 1991. More than 700 died, 200000 became homeless, buildings collapsed,crops destroyed, agricultural land ruined by ash
Multi Hazardous Environment Case Study-The Philippines–Seismic Hazards
Earthquakes occur along Philippine plate boundary and at fault lines where the plate cracked under pressure
Multi Hazardous Environment Case Study-The Philippines-Earthquake Example
A 7.8 magnitude earthquake hit Luzon island. Over 1500 killed
Multi Hazard Environment Case Study-The Philippines-Earthquake and Tsunami example
A 7.9 magnitude earthquake caused a tsunami which hit the Moro Gulf. Thousands died and cities were destroyed
Multi Hazard Environment Case Study-The Philippines-Tropical Storms
The Philippines has 10 tropical storms a year. They develop in the Pacific Ocean and move westwards over the islands
Multi Hazard Environment Case Study-The Philippines-Tropical storm case study
Typhoon Xangsane destroyed houses, caused flooding,landslides and the loss of power and water. 200 died
Multi Hazard Environment Case Study-The Philippines–Management Strategies
- Preventing development of high risk areas
- Adaptation of buildings to cope with earthquakes
- Building embankment to reduce flood risk
- Increasing public awareness of hazards
- Monitoring hazards
- Early warning system developed
Case Study-Boscastle Floods-Causes
- Intense heavy rain-remnant of Hurricane Alex and through line above Boscastle
- Surrounded by slate valleys-Water runs quickly
- Saturated ground-Prevent water entering ground
- Deforestation
- More water in rivers
Case Study-Boscastle Floods-Social Impacts
- Flooded houses
- Water and power supplies damaged
- People broke bones
- No deaths
- 50 cars lost
- Tourism was affected
- Businesses destroyed
Case Study-Boscastle Floods-Economic Impacts
- Insurance Claims
- Businesses damaged
- Loss of tourism
- Lower bridge was destroyed
Case Study-Boscastle Floods-Environmental Impacts
- Raw sewage was washed out to sea and into river
- Damage to animal habitats
Case Study-Boscastle Floods-Short Term Responses
- Emergency services sent out
- People evacuated to Camelford
- Prince Charles donated a large sum of money
- Sandbags were used
Case Study-Boscastle Floods-Long Term Responses
- Reconstruction project
- Channel was widened and deepened to increase capacity
- Lower bridge replaced by stronger structure
- Buildings reconstructed in a environmentally friendly way
- Tourism increased since the floods-due to the flood
