Hazards

Question 1

what are the three main types of physical categories in natural hazards?

Answer 1

• Geophysical: involving geological processes
  > earthquakes, volcanoes, landslide
• atmospheric: involving processes acting in the atmosphere
  > hurricane, tornadoes, tropical storms
• hydrological: processes involving water
  > flash flooding,

Question 2

What is the makeup of the earth’s internal structure?

Answer 2

• 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

Question 3

What are the positives of the parks model?

Answer 3

• 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

Question 4

what are negative of the parks model?

Answer 4

• 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

Question 5

what are the positives of hazard management cycle?

Answer 5

• as events keep happening, ongoing mitigation may reduce impacts

Question 6

what are the negatives of the hazard management cycle?

Answer 6

• less suited to unexpected hazards
• not able to track progress over time
• LIC may not be able to afford some stages

Question 7

what is a disaster?

Answer 7

when a hazard seriously effects humans

Question 8

what is the vulnerability?

Answer 8

how susceptible a population is to a hazard

Question 9

what is risk?

Answer 9

the likely hood that humans are effected by a hazard

Question 10

what are the stages of the Parks Model?

Answer 10

• 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

Question 11

what are the stages of the hazard management cycle?

Answer 11

• 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,

Question 12

what are the responses people can have to hazards?

Answer 12

• 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

Question 13

what can change a person’s perception to a hazard?

Answer 13

• wealth
• education
• experience
• religion
• age

Question 14

what are the economic impacts of a hazard?

Answer 14

• 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

Question 15

what are the social impacts of a hazard?

Answer 15

• 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

Question 16

what are the political impacts of a hazard

Answer 16

• anger at the government due to lack of supplies
• criticism of preparedness
• government spending money on repairs rather than development

Question 17

what are the environmental impacts of a hazard?

Answer 17

• 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

Question 18

How are mid-ocean ridges formed?

Answer 18

• 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

Question 19

How are rift valleys formed?

Answer 19

• 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

Question 20

what happens when an oceanic plate meets continental plate? (destructive plate boundary)

Answer 20

• 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

Question 21

what happens when a oceanic and oceanic plate meets

Answer 21

• 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

Question 22

what happens when a continental plate meets a continental plate

Answer 22

-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

Question 23

what are the hazards at the three types of plate boundaries?

Answer 23

• 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