L8 - Reducing the risk of

• reasons for living with the risk

  volcanoes - brings benefits such as fertile soils, rocks for buildings, rich mineral deposits and hot water
• reasons for living with the risk

  volcanoes - brings tourists to the area and this provides many jobs for local people
• reasons for living with the risk

  volcanoes - brings geothermal energy to the area which is cheaper
• reasons for living with the risk

  volcanoes - extremely fertile soils for farming
• reasons for living with the risk

  volcanoes - more effective monitoring is happening
• reasons for living with the risk

  both volcanoes and earthquakes - they dont happen very often
• reasons for living with the risk

  volcanoes and earthquakes - some people are unaware of risks
• reasons for living with the risk

  volcanoes and earthquakes - some people can’t afford to move
• reasons for living with the risk

  volcanoes and earthquakes - people dont want to leave their family and friends
• reasons for living with the risk

  earthquakes - fault lines allow water supplies to reach the surface which is important in deserts
• reasons for living with the risk

  earthquakes - can be relatively safe if you are well prepared
• reasons for living with the risk

  earthquakes - better building designs mean less risk
• monitoring

  using scientific equipment to detect warning signs of events such as a volcanic eruption
• prediction

  using historical evidence and monitoring, scientists can make predictions about when and where à tectonic hazard may happen
• protection

  designing buildings that will withstand natural hazards
• planning

  identifying and avoiding places most at risk
• monitoring

  • networks of seismometers and lasers monitor earth movements, and can be used in early warning systems to give small (seconds), but vital time before a large earthquake
  • scientists can monitor the tell tale signs that come before a volcanic eruption such as small earthquakes, escaping gas and changes in the shape of the volcano all mean that an eruption is likely
• prediction (important for volcanoes)

  • earthquakes cannot be predicted but by monitoring the movement of tectonic plates, scientists can forecast which areas should be prepared
  • volcanic eruptions cannot be predicted if the volcano is well monitored. predicting when a volcano will erupt gives time for evacuation and reduces the number of injuries and deaths
• protection (important for earthquakes)

  • buildings can be designed t withstand earthquakes
  • existing buildings and bridges can be strengthened so they are less likely to collapse under the weight of falling ash or due to shaking from an earthquake
  • automatic shut off switches can be fitted that turn off gas and electricity supplies to prevent fires if an earthquake is detected by a monitoring ssystem
• planning:

  • future developments can be planed to avoid the areas most at risk from tectonic hazards
  • emergency services can train and prepare for disasters to reduce the number of people killed
  • people can be educated on what to do if something does happen
  • governments can plan evacuation routes to get people out of dangerous areas quickly and safely to reduce the number of people killed by things like fires, pyroclastic flows or mudflows
  • emergency supplies like blankets, clean water and food can be stockpiled
• ways of monitoring and predicting:

  • seismologists can use radon detection devices to measure radon gas in the soil and can be used to measure small tremors or foreshocks before the main earthquake
  • smart phones have GPS receivers and accelerators built in which can detect movements in the ground
  • animals are believed to act strangely when an earthquake ils impending
• planning:

  • furniture and objects can be fastened down so they are secure
  • residents can learn to turn off their gas, water and electricity supplies to their properties
  • preparing emergency supplies such as food, medicine and water are accessed faster
  • practice earthquake drills
  • earthquake safety checklist to help people plan
• protection:

  • buildings made of brick or buildings with no reinforcement collapse more easily during an earthquake
  • characteristics of earthquake resistant buildings include rubber shock absorbers, deep foundations, open areas, fire resistant materials, identification number on roof for helicopters, automatic shutters on windows and interlocking steel frame
  • however they are very expensive
• its easier to predict volcanic eruptions than earthquakes. volcanoes usually give advance warning signals that they are going to erupt, however the exact time and day of the eruption is difficult to predict
• ways of predicting volcanoes:

  • satellites, and tiltmeters monitor ground deformation
  • seismometers measure small earthquakes and tremors
  • thermal heat sensors detect changes in temperature of the volcanoes surface
  • gas-trapping bottles and satellites measure radon and sulphur gases released
  • scientists measure the temperature of water in streams and rivers to see if it has increased
• volcanic eruption signs:

  • water heated by magma causes steam eruptions
  • gases rising from magma
  • heat melts snow
  • sides of volcano swell as magma rises
  • rocks fracture as rising magma causes earthquakes
• protection:

  buildings cannot be designed to withstand the lava flows, lahars or weight of debris and ash falling, so people need to evacuate to a safe location
• the sheer power of a volcanic eruption often means there is little that can be done to protect people and property. however it is possible to use embankments or explosives to divert lava flow away from property.
• how to plan for a volcanic eruption:

  • evacuation plan
  • emergency shelter
  • food supplies
  • exclusion zones
  • practise covering eyes, nose and mouth to prevent inhalation of poisonous gas fumes
• the interlocking steel frame prevents the building falling down and crushing people
• the open area prevents other buildings from being destroyed in case the building does fall down
• the rubber shock absorbers reduce the effect of the earthquake shocks and help prevent the building from getting damaged and crushing people
• the identification number makes it easy for helicopters to locate and help injured casualties