hazards

• Hazard


  Something that is a potential threat to human life or property.
• Natural hazards


  Are caused by natural processes
• What are the three types of natural hazards?

  Geophysical hazards, atmospheric hazards and hydrological hazards.
• Disaster


  When a hazard actually seriously affects humans.
• Vulnerability


  How susceptible a population is to the damage caused by a hazard.
• Impacts of hazards

  Hazards can have significant impact while they are occurring and often need an emergency response. Impacts can also go on for a long time after the Hazard has passed.
• How do you people circumstances affect their perception of hazards?


  People view hazards in different ways for example some people believe that they will never experience a hazard and some adapt their lifestyle to minimise risk and some accept hazards as being beyond their control
• How do peoples circumstances affect the perception of hazards?


  Their perceptions are affected by their economic social and cultural background. Wealth if they can afford to move away, religion some people feel they are acts of God to punish people, education they have a better understanding of the risks and how they may be able to reduce them past experiences and personality.
• There are many responses to hazards that individuals and the government may take, to try to reduce vulnerability and its impacts.


  People may try to prevent a hazard or juices magnitude for example building flood defences.

  Risk sharing involves sharing the cost of reducing hazard, the benefits of preventing it and the cost of not preventing it.

  People may try to mitigate the impacts of a hazard this could be by protection and adaptation.

  Fatalism

  Governments may coordinate responses to a hazard to manage effectively.
• Hazard incidence

  How often a Hazard occurs.
• Magnitude or intensity


  How powerful the hazard is
• Distribution


  The areal extent of the hazard.
• Low incidence and high magnitude hazards are

  More destructive.
• Level of development can affect how well countries manage hazards affectively


  Because of lack of wealth and technology.
• What does the park model show?


  The park model shows the different phases of response to a hazard.
• The park model - predisaster


  Before the event the situation is normal.
• The park model - disruption


  During and directly after the hazard event occurs there is destruction of property and loss of life before people begin to respond.
• The park model - relief.


  In the aftermath of the event rescue efforts focus on saving people and preventing further damage.
• The park model - Rehabilitation


  Once the immediate impact is under control people can start to resolve longer term problem.
• The park model - reconstruction


  This involves rebuilding permanent houses and infrastructure this results in one of two outcomes buildings being built to the same standard as before and the area returned to normal or buildings are built to a higher standard than before and the area improves.
• How is the park model good?

  Shows how responses progress during a disaster which may help learners predict what resources will be needed for each stage, also helps planners to prepare for future hazard events for example the reconstruction phase of the model shows that conditions can be improved after a disaster which will help to mitigate the impacts of future hazard events.
• What are the four phases in the hazard management cycle?


  Mitigation preparedness and response and recovery
• What are the four phases in the hazard management cycle for?


  Mitigation aims to minimise the impact of future disasters, preparedness is about planning how to respond to hazard, response is how people react when a disaster occurs and recovery is about getting the affected area back to normal.

  It's a cycle because hazard events keep happening so efforts to prepare for them or mitigate them are ongoing.
• Geophysical hazards


  Caused by land processes such as earthquakes and volcanoes.
• Atmospheric hazard


  Caused by climatic processes such as tropical cyclone storms and droughts
• Hydrological hazards


  Caused by water movement for example floods in avalanches
• The inner and outer core contain lots of


  Iron and nickel
• The inner core is


  A solid ball
• The outer core is


  Semi molten
• What is that is the asthenosphere?

  The upper bit of the mantle that is below the lithosphere it is semi molten.
• What is the lithosphere?

  The rigid top part of the mantle and the crust.
• Which type of crust is thicker?

  Continental crust is thicker at 30-70km but is less dense than oceanic crust which is thinner at 6-10 km but more dense.
• What is the earths main internal source of energy?


  Some of the heat energy is leftover from when the earth formed and some is left over from radioactive decay of elements such as uranium.
• What are the theories of how tectonic plates move?

  Convection Currents, Ridge Push and Slab Pull.
• How do convection currents move tectonic plates?


  The core is very hot and lower parts of the asthenosphere heat up and slowly rise. As they move towards the top of asthenosphere they cool down and become more dense and slowly sink. The circular movements of the semi molten rock create drag on the base of the tectonic plate causing them to move.
• How does Slab Pull move tectonic plates?


  At Destructive plate margins, denser crust is forced under less dense crust.
• How does Ridge Push move tectonic plates?


  At constructive plate margin magma rises to the surface and forms new crust. This heats the surrounding rocks which expand and rise above the surface of the surrounding rocks forming a slope. As the new crust cools and becomes denser, gravity causes the denser rock to move down slope away from the plate margins, this puts pressure on the plate margins, causing them to move apart. ( also know as gravitational sliding )
• Seafloor spreading


  As tectonic plates diverge, magma rises up to fill in the gap created this then cools to form new crust. Over time the new crust is dragged apart to form more new crust. When this happens at a plate margin under the sea the plate margin gets wider.
• What does seafloor spreading create?


  Mid ocean ridges.
• What are the three types of plate margins?

  Constructive destructive and Conservative