1.2.3 Management of Tectonic Hazards

• Why People Live in Areas at Risk

  • It is estimated that by 2025, 600 million people will live in tectonically active areas.
• There are also many economic advantages to living in tectonically active areas, particularly where there are volcanoes including:

  • Fertile soils
  • Tourism
  • Minerals and precious stones
  • Geothermal energy
  • Creating new land area
• • Fertile soils: The ash and cooled lava contain many minerals which lead to high yields of crops
  • Tourism: Many people want to visit areas where there are active volcanoes, this increases the number of jobs available 
  • Minerals and precious stones: These can be mined and sold providing work for local people
  • Geothermal energy: As the magma is closer to the surface the heat can be used to generate geothermal energy
  • Creating new land area: Once the lava and ash have cooled, new land areas are formed
• • There are also social reasons for living in these areas, including:
  • People don't want to leave family and friends
  • They have always lived there and don't want to leave
  • As technologies and prediction improve people are also more confident that they are prepared for the hazard 
• Management of Tectonic Hazards

  • To reduce the risks from tectonic hazards there are four key management strategies
  • Monitoring
  • Prediction
  • Protection
  • Planning
• Monitoring 

  • Active volcanoes are monitored using a range of equipment:
  • Seismometers
  • Lasers and tiltmeters
  • Remote sensing
  • Gas sensors
  • Earthquakes: 
  • Seismometers
  • Gas sensors
  • Ground water levels
• Monitoring

  
  

  Volcano Monitoring: 

  • Seismometers: These record earth movements and can detect the slightest tremor.
  • Lasers and tiltmeters: Used to detect ground deformation, changes in land shape can be a sign of rising magma.
  • Remote sensing: Satellites are used to detect heat increases within the volcano another sign of rising magma.
  • Gas sensors: These detect increases in gases such as sulphur and radon which increase before an eruption.
• Monitoring 

  Earthquakes Monitoring:

  • Seismometers: These record earth movements and can be used to detect foreshocks.
  • Gas sensors: Detect increases in radon gas which some scientists believe is released prior to an earthquake.
  • Ground water levels: Changes in groundwater levels have been recorded before earthquakes.
• Prediction

  • Volcanoes:
  • Monitoring of volcanoes now allows more accurate predictions of eruptions to be made
  • This allows for evacuation and exclusion areas to be put in place
  • Accurate timings for eruptions are not possible 
  • Earthquakes: 
  • Impossible to predict date, time or location
• Protection

  • Volcanoes:
  • Evacuation and exclusion zones move people out of areas at risk 
  • Buildings cannot be protected against lava or pyroclastic flow
  • Strengthening of roofs to support weight of falling ash
  • Earthquakes:
  • Many countries now practice earthquake drills - 'drop, cover and hold on' ensuring people know how to best protect themselves in an earthquake
  • Earthquake resistant building design - such as shutters on windows and reinforced steel cross braces
  • Sea walls to protect against tsunami
• Planning

  • Volcanoes and earthquakes:
  • Hazard mapping and risk assessment are used to identify areas which are at greater risk - this means people can be moved or building restricted in those areas, particularly essential buildings (hospitals) and transport
  • Evacuation plans
  • Education about what actions to take, including drills
  • Stockpile of emergency supplies
  • Training of emergency services
• Question:

  State two ways that planning might help to reduce the damaging effects of an earthquake or volcanic eruption.

  Answer:

  • Any two of the following could be used:
  • Prepare emergency aid and distribution [1]
  • Earthquake/volcano drills [1]
  • Evacuation routes [1]
  • Stockpile blankets/food/water [1]
  • Educate people so they know what to do if an earthquake or eruption happens [1]
  • Prepare hazard maps to identify areas most at risk [1]
  • Planning to avoid new buildings in areas at risk [1]