HAZARDS Flashcards
3 types of geological hazards
Geophysical- land
Atmospheric- wind
Hydrological- water
Perception
How people have different viewpoints of how dangerous hazards are and the risk they pose.
Dependant on lifestyle factors.
E.g a wealthy person worries less as they have to money to solve the damage
Fatalism
The viewpoint that hazards are uncontrollable natural events
Losses should be accepted as there is nothing we can do about it.
Prediction
Using scientific research and paste events, to know when a hazard might take place.
So that warnings can be delivered and the impacts can be reduced.
Adaptation
Attempting to live with the hazard
Adjusting lifestyle choices
So that vulnerability of the hazard is reduced
Mitigation
Strategies that help to reduce the severity of the hazard
Management
Strategies to reduce the hazards effects
Risk sharing
Community preparedness: share risks and invest collectively.
Park model
Graphical representation of steps carried out in HAZARD RECOVERY
Rough time frame
Good for comparing hazards
Stages of the park model 1,2,3
1- relief. (Hours and days). Immediate local response: medical age, search and rescue
2- rehabilitation. services begin to be restored. Food and water. Temporary shelters.
3- reconstruction. Restoring the area
Hazard management cycle
Outlines the stages of responding to events, showing the same stages take place after every hazard
4 stages of the hazard management cycle
Preparedness.
Response
Recovery
Mitigation
Inner core
Solid ball of iron or nickel
Very hot due to pressure and radioactive decay
Responsible for earths internal energy
Outer core
Semi- molten
Iron/ nickel
Mantle
Main,y solid
Rocks high in silicone
Top of many,e is the asthenosphere
Asthenosphere
Semi molten
Moves due to convection currents
Lithosphere above
Lithosphere
Broken up into plates
Top is the crust
Crust
Thin top of the lithosphere
Oceanic crust is dense and is destroyed by plate movement
Continental crust is less dense and is NOT destroyed
Destructive plate boundaries direction
Towards
Conservative movement
Along side
Constructive movement
Away from eachother
Landforms made by destructive plate margin
Volacnoes
Fold mountains
Earthquakes
Island arcs
Ocean trenches
Landforms made by conservative
Eq
Landforms made by constructive
Volcanoes
Eq
Ocean ridges
Rift valley
Destructive (continental and oceanic)
Denser oceanic plate subducts below continental
Leave a deep ocean trench
Destructive (oceanic and oceanic)
Heavier plate subducts leaving an ocean trench
Built up pressure causes and underwater volacnoes
Lava cools and causes island arcs
Destructive (continental and continental)
Both plates not as dense
Oceanic is subducted slightly
Fold mountains form
Ridge push
Gravity pushes plates further away
Widens gap
Known as gravitational sliding
Slab pull
When a plate subducts
Plate sinks into the mantle and pulls the rest of the plate
Hotspots
Areas of volcanic activity
Not related to plate boundaries
Hot magma plumes burn though weaker parts of the crust
Creates volcanoes and islands
Hawaii
Hazards caused by volcanoes
Lava flows
Lahars
Floods
Tephra
Toxic gases
Acids
Pyroclastic flows
Primary effects of a volcano
Environ- ecosystems damaged. Wildlife killed
Economic- businesses and industries destroyed
Social- people killed. Homes destroyed
Political- government buildings destroyed
Secondary effects of a volcano
Environ- acid rain. Greenhouse effect
Economic- jobs lost. Profit from tourism
Social- fires can start. Mudflows or floods. Trauma. Homelessness.
Political- conflicts about government response
Shockwaves
Energy released from sudden jolt that vibrates through the ground
Tsunamis
Caused when water is displaced by plates moving underwater. Creating a large wave
Liquefaction
When soil is saturated, the vibrations cause it to act like liquid
Soil becomes weaker and more likely to move.
Causes landslides and avalanches
Primary effects of a seismic hazard
Environ- cause fault lines. Destroy the environment. Liquefaction
Economic- businesses destroyed.
Social- buildings collapse. Traps people
Political- government buildings destroyed
Secondary effects of seismic hazards
Environ- saltwater flood freshwater ecosystems. Radioactive materials.
Economic- money declines as businesses are destroyed. High cost of rebuilding.
Social- gas pipes rupture. Disease spreads.
Political- borrowing money
Tropical storm
Air is heated up from 27* water or more
Air rises and condenses and forms clouds
This releases energy
Moisture is blown out, causing torrential rain
Air spins due to the Coriolis Effect and spirals round the eye.
Cold and denser air sinks in the eye- making it clear and dry.
Hazards caused by tropical storms
High winds
Flooding
Landslides
Storm surges
Condition for a TS to form
At least 27*c
At least 50m deep
Unstable air pressure
What is the magnitude for a TS measured on
Saffir- Simpson scale
Based on 1-5
Regularity of TS
Irregular
Paths do not follow a set route
Predictability of a TS
Form away from land
Satellite tracking
General route can be calculated
Primary effects of a TS
Environ- beaches eroded, sand displaced, coastal habitats destroyed
Economic- businesses destroyed. Agricultural land damaged
Social- drowning, debris can injure or kill people
Political- government buildings destroyed
Secondary effects of a TS
Environ- river flooding, animals displaced,
Economic- high cost of rebuilding, loss of income- sources
Social- homelessness, polluted water supplies spread diseases, food shortages
Political- issues with international aid, pressure from government about global warming.
Prevention of a TS
Cannot be avoided
Preparedness
Education
Evacuation plans
Storm warning systems
Mitigation
Search and rescue
Strengthening home
Clearing loose debris
Adaptation
Move away from risk area
Design better buildings
Flood defences
Wildfire
An uncontrollable fire that quickly spreads though vegetation
Favourable vegetation type of a wildfire
Thick, close together vegetation
Trees and thick bushes
Vegetation with flammable oils- eucalyptus
Dry
Human causes of wildfires
Arson, bbqs, lit cigarettes, agriculture, train lines
Natural causes of WF
Spontaneous combustion
Volcaneos
Lightning
Primary effects of wildfires
Environ- air pollution, water pollution, toxic gases
Economic- businesses destroyed, agricultural land damaged
Social- people killed, homes destroyed, people gone missing
Political- government buildings destroyed
Secondary effects of WFs
Environ- migration patterns of animals, seed germination
Economic- high cost of rebuilding, lost income sources, planes cancelled
Social- homelessness, food shortages, health problems, ptsd
Political- borrowing international aid money, pressure from government about global warming.
Prevention of WFs
Not be avoided
Awareness about human controlled fires
Preparedness
Public awareness
Evacuation plans
Satellite images
Red flag warning
Mitigation
Search and rescue
Removing flammable material- leaves
Spraying water
Adaptation
Move away from risk area
Fire breaks to stop the spread
Reducing carbon footprint
Insurance to cover damage
Ocean ridge
Plates move apart
Underwater volacnoes can erupt and build up to reach surface to form islands
Rift valley
Rising magma that causes the crust to bulge and fracture.
Causes faults
Land between the fault drops down to form a rift valley
Great African rift
Fold mountains
When sediments fold upwards
Himalayas
How often do low magnitude seismic hazards occur
Frequently
Can be 100s of small ones a day
What are TS measured on
Safari-Simpson scale
What is the frequency of TSs
100 per year
How do they predict and track TS
Using satellite imagery and models
What conditions are needed for a wildfire
Vegetation
Fuel
Climate and weather
Fuel
Natural
Human
When did BS happen
Feb 2009
What are the effects of BS
173 deaths
3500 properties destroyed
7000 people displaced
1 million animals killed
Properties were looted
What is a high incidence hazard
Every month
Frequent
What is a low incidence hazard
Every century
Infrequent
Factors of a low incidence hazard
Harder to predict
Less management strategies
Hazard could be more catastrophic when it does occur
More intense
How can a country having a low level of development affect when a hazard is proposed?
Less likely to have effective mitigation strategies as they are costly.
More catastrophic as less prevention in place.
The park model
Graphical representation of human responses to hazards
Shows steps carried out in the recovery afater a hazard.
Gives a rough time frame indication.
Steepness of curve: shows how quickly an area deteriorates and recovers.
Depth of curve: shows the scale of the disaster. Lower curve- lower quality of life.
3 stages of the park model
Stage 1- relief (hours/ days)
Stage 2- rehabilitation (days- weeks)
Stage 3- reconstruction (weeks-years)
How is the park model useful
Control line to compare hazards
Hazard management cycle
Outlines stages of responding to events, showing how the same stage takes place after every hazard.
Hazard management what are the 4 stages in the cycle
Preparedness
Response
Recovery
Mitigation
Evaluating the effectiveness of models
- cannot predict the human responses to hazards.
- does it include factors such as climate change?
Asthenosphere
Semi-molten layer
Constantly moving due to convection currents
Movements powered by heat from the core
Lithosphere is above
Lithosphere
Broken up into plates
Majority is with the mantle
Top is the crust
Oceanic crust
Dense and is destroyed by plate moment.
Continental crust
Less sense
Hotspots
Areas of volcanic activity that are not related to plate boundaries
Hot magma plumes from the mantle rise and burn through weaker parts of the crust
Can create volacnoes and islands- Hawaii.
Causes a chain o9f islands as the plates move
Lava flows
Lava flows quickly or slowly depending on its viscosity
Silica makes lava viscous and slow, which is common in explosive eruptions
Lahars
Mudflows
Cased by ice melting at high latitudes
Tephra
Any type of rock that is ejected by volcanoes
Toxic gases
Released during some eruptions
Co2 even a toxic gas.
Acid rain
Caused when gases- sulphur dioxide are released into the atmosphere
Nuees ardentes
Pyroclastic flow
Clouds of hot burning ash and gas that run down the side of a volcano at high speeds
60-430mph
Tsunami
Oceanic crust is jolted during an earthquake
All water above the plate is displaced
Liquefaction
Soil is saturated
Vibrations of an earthquake caused it to act a liquid
Soil becomes weaker- causing it to subside
E.g Christchurch in New Zealand
What does the Safari-Simpson scale measure
Intensity of tropical cyclones
Scale of 1-5
Based on wind speed and. Thus power of the storm
Storm surges
Large rise in sea levels caused by low pressure and high winds
Pushing water towards the coast
