Hazards Flashcards
what are the three main types of physical categories in natural hazards?
- Geophysical: involving geological processes
> earthquakes, volcanoes, landslide - atmospheric: involving processes acting in the atmosphere
> hurricane, tornadoes, tropical storms - hydrological: processes involving water
> flash flooding,
What is the makeup of the earth’s internal structure?
- 6 different layers each with different viscosity and thickness
- crust, lithosphere, asthenosphere, mantle, outer core, inner core
- crust is thin and ridged
> average 30 km thickness - mantle is dense and semi-solid
> able to be split into upper and lower mantle - upper mantle is split into lithosphere and asthenosphere
> asthenosphere is semi-solid
> lithosphere is rigid - centre is the core
> outer core is liquid, inner core is solid due to pressure
What are the positives of the parks model?
- helps predict resources needed at each stage of
- if improvements made, will prevent further impacts which reduces vulnerability
- curve is able to track progress over time
- able to show the impact on the quality of life due to the hazard
- shows a measurable change in normalily
what are negative of the parks model?
- assumes the country is at normality
> doesn’t factor in other events in quick succession - LIC may not able to return to normal due to lack of money
what are the positives of hazard management cycle?
- as events keep happening, ongoing mitigation may reduce impacts
what are the negatives of the hazard management cycle?
- less suited to unexpected hazards
- not able to track progress over time
- LIC may not be able to afford some stages
what is a disaster?
when a hazard seriously effects humans
what is the vulnerability?
how susceptible a population is to a hazard
what is risk?
the likely hood that humans are effected by a hazard
what are the stages of the Parks Model?
- pre-disaster: normal conditions
- disruptions: during or directly after disaster
> steep decrease in quality of life - relief: aftermath of the hazard, rescue and minimising further disruptions
> curve settles out, starts to go back up - rehabilitation: once immediate impacts are under control, long term
- reconstruction: rebuilding from the damages
> same or improved standard of life
what are the stages of the hazard management cycle?
- preparedness: planning how to respond to the hazard
> warning systems, education - disaster
- response :how people react when a disaster occurs
> rescue, - recovery: getting area back to normal
> rebuilding - mitigation: minimising impact of future disasters,
what are the responses people can have to hazards?
- fatalism: there is nothing able to be done to avoid the hazard
- adaptation: adjusting how to life with hazards
- mitigation: reduce impact of the hazard
- prediction: predicting when an where the hazard is going to be
- risk share: reducing the cost of the hazard
> insurance
what can change a person’s perception to a hazard?
- wealth
- education
- experience
- religion
- age
what are the economic impacts of a hazard?
- businesses destroyed
> loss of employment which effects the economy - may need to rely on imports
- cost of repairs/rebuilding
- agricultural land damaged
> loss of food - insurance premiums increase
what are the social impacts of a hazard?
- death/injuries of people due to hazard
- destruction of homes/temples
- breathing problems due to air quality/smoke
- disease due to lack of sanitation due to contamination of water supply
- debris blocking evacuation/emergency services
- lack of food/supplies/energy
what are the political impacts of a hazard
- anger at the government due to lack of supplies
- criticism of preparedness
- government spending money on repairs rather than development
what are the environmental impacts of a hazard?
- habitats destroyed
- loss of species
-soil damage/ eroded - air and water pollution
> due to sewage or salt - may be an increase in GHG
- acid rain
- leak of chemicals/ radioactive material
How are mid-ocean ridges formed?
- the mid ocean ridge forms when the (constructive) diverging plates are under the ocean
- As the plates move apart, magma rises up to fill the gap and this accumulates over time to become taller and wider
How are rift valleys formed?
- rift valley forms when the diverging plates are beneath the land (continental)
- As the plates move apart, the crust / lithosphere stretches and fractures
- Areas of crust drop down between faults to create a valley
what happens when an oceanic plate meets continental plate? (destructive plate boundary)
- subduction of the dense oceanic plates under continental
> forms a deep ocean trench
> at 100km the oceanic plate starts to melt, fully melt at 700km
> melting zone is called benioff zone
> melting oceanic plate creates magma which will rise in plumes in the fold mountains (volcano) - continental plate is lifted and compressed and forms fold mountains
what happens when a oceanic and oceanic plate meets
- one plate which is faster or denser subducts beneath the other
> forms a deep ocean trench - rising magma from the Benioff Zone forms submarine volcanoes along the plate margins which make island arcs
what happens when a continental plate meets a continental plate
-Two plates of similar density move towards each other
- Neither is dense enough to subduct so the land is pushed upwards
- This forms fold mountains
- Earthquakes are the main hazard at this type of plate boundary
- There is no volcanic activity because there is no subduction
what are the hazards at the three types of plate boundaries?
- constructive plate boundary
> mild and shallow earthquakes
> volcanic eruptions but tend to less
explosive - destructive plate boundary
> Friction and pressure build up in the
Benioff zone causing strong
earthquakes
> Volcanic eruptions tend to be explosive - conservative plate boundary
> Plates can stick causing a significant
build up of pressure and powerful
earthquakes
