hazards mock Flashcards
park model stage 1
- pre disaster = before event
park model stage 2
- disruption = during and directly after hazard, there is destruction of properly and loss of life
park model stage 3
- relief = rescue efforts in the aftermath focus on saving people and preventing further damage
park model stage 4
- rehabilitation = people resolve longer term problems and provide temporary shelter and aid
park model stage 5
- reconstruction = rebuilding permanent houses and infrastructure, area could return to normal or improve and vulnerability to hazards decreases
how many stages does the park model have?
5
positives of park model
- clear visualisation of stages
- allows areas to be compared
- links to how developed/ prepared an area is
negatives of park model
- too general and simple
- doesn’t account for the difference in recovery time in urban and rural areas
- doesn’t consider multiple hazards
hazard management cycle phase 1
- mitigation = aims to minimise impacts of future disasters e.g. building flood defences (before or after event)
hazard management cycle phase 2
- preparedness = planning how to respond to a hazard e.g. warning systems
hazard management cycle phase 3
- response = how people react when a disaster occurs e.g. emergency services rescue people
hazard management cycle phase 4
- recovery = getting the affected area back to normal e.g. rebuilding houses
how many phases are in the hazard management cycle
4
positives of the hazard management cycle
- covers all phases
- shows long term planning
- can be applied to multiple hazards
negatives of the hazard management cycle
- too simple
- does not account for economic inequality
- assumes that governments will address all phases equally
hazard mitigation is…
anything done to reduce the severity or impacts of a hazard through short term or long term responses
3 main categories of long term responses
- prevention
- preparedness
- adaptation
prevention
- not possible to prevent volcanic eruptions
- risk could be prevented if authorities do not develop on the land around a volcano
preparedness
- happens before to minimise risk or vulnerability
- monitoring systems and evacuations
- stop people from entering area
- emergency kit and finding emergency shelter
- search and rescue units set up and fire response units
adaptation
- how people change their behaviour to minimise risk
- buildings can be strengthened to reduce chance of collapse under ash
- people can capitalise on opportunities such as farming (fertile ash soil) or tourism
primary impacts are…
a direct result of the eruption
secondary impacts are…
a result of the primary impacts
social impacts of volcanic eruptions
- people killed and infrastructure destroyed
- pyroclastic flow and lava can cause fires
- lahars and flooding from ice melt can cause damage and death
environmental impacts of volcanic eruptions
- ecosystems damaged or destroyed by volcanic material
- acid rain can enter water and kill organisms
- acid rain damages trees and removes nutrients from soil
- volcanic gases can add to greenhouse effect
- ash clouds can block sunlight, lowering temperatures
economic impacts of volcanic eruptions
- destroy businesses, damage crops, prevent air travel
- damage can be expensive to repair
- eruptions can attract tourism and boost economy
political impacts of volcanic eruptions
- food shortages due to damaged land can lead to conflict
- government spending money on reparations rather than services so development slows
soufriére hills volcano
- montserrat, caribbean
- destructive plate margin, NA plate subducting below caribbean plate
- series of eruptions 1997
- 5 million m^3 of material released in 20 mins
- pyroclastic flow and large ash clouds
economic impacts of soufriére hills eruption
- £1 billion in homes and investments lost
- over 20 villages lost
- businesses destroyed lowering economy (more tourism now)
- schools, hospitals, airport and port destroyed
social impacts of soufriére hills eruption
- 19 died
- hundreds lost homes
- fires destroyed government offices and police headquarters
- 8000/12000 inhabitants left
environmental impacts of soufriére hills eruption
- plymouth (capital city) buried under 12m of mud and ash
- vegetation and farmland destroyed
- volcanic ash has improved soil fertility
8 responses to soufriére hills eruptions
- people evacuated to safe areas north
- shelters built for evacuees
- temporary roads and electricity supplies
- UK provided £17 million emergency aid
- local services provided search and rescue
- risk map created with exclusion zone
- UK provided £41 million of long term aid to develop new port, airport and houses
- montserrat volcano observatory set up to predict future eruptions
convection currents
- lower parts of asthenosphere heat up and rise
- as they reach the top, they cool down and become more dense and sink
- circular movements create drag on the base of the tectonic plates and move them
slab pull
- at destructive margins, denser crust subducts below less dense crusts
- sinking of plate edge pulls the rest of the plate towards boundary
ridge push
- constructive margins, magma rises to form new crust in a slope shape
- denser rock moves away from plate margin which puts pressure on plates below causing them to move apart
sea floor spreading
- as plates diverge, magma fills gap
- sea flood gets wider
- creates mid ocean ridges
