Hazards

• What are the different types of volcanoes? (How active they are)

  Active -> Currently erupting or can erupt at any point

  
  

  Dormant -> Hasn't erupted in the past 2000 years

  
  

  Extinct -> Will not erupt again, no evidence of magma feeding into it / no magma chamber
• What are the different type of volcanic eruptions?

  Effusive eruptions -> Gentle eruptions such as hotspots or shield volcanoes

  
  

  Phreatomagmatic eruptions -> Caused when eruption meets ice and much more explosive

  
  

  Explosive eruptions -> Very aggressive such as composite volcanoes
• What are some of the impacts of volcanoes?

  Expensive to repair

  Death and injury due to pyroclastic flow or lava flows

  Destruction from pyroclastic, lava, mud flow

  Ecosystems destroyed

  Eruptions can destroy businesses, damaging economy

  Flights stopped due to ash fallout
• What are some of the responses to volcanic hazards? (PPA)


  Preparedness:

  Locals may have emergency shelters

  Educate locals

  Monitoring systems to minimise risk

  
  

  Prevention:

  Evacuation

  Stay indoors

  
  

  Adaptation:

  Some may adapt and attempt to capitalise on certain opportunities such as farmers; volcanic ash makes soil fertile so farming will grow exponentially.
• What are pyroclastic flows?


  Super heated gasses, ash and volcanic rock which flows quickly down the sides of the volcano. They come without little warning and can causes death and mass destruction.
• What are lava flows?

  Magma flowing out the mantle and down the volcano, how fast it flows depends on temperature and viscosity (low = runny, high = slow). Usually, flows slow so people can evacuate, but will destroy anything in its path.
• What is tephra?


  Rock fragments that are ejected into the atmosphere during the eruption. Larger fragments are referred to as volcanic bombs.
• What are lahars? (Mudflows)


  When volcanic material mixes with large amounts of water (from ice melting or precipitation). This can travels for tens of hundreds and bury or destroy natural habitats and infrastructure.
• What is acid rain?


  When volcanic gasses mix with water vapour in the atmosphere it creates acid rain which can destroy ecosystems and can cause chemical weathering.
• What is ash fallout?


  Ash which can travel for thousands of kilometres and cause harm to humans or animals when inhaled.
• What are volcanic gasses?

  Gases such as C02 and Sulfur dioxide are released during the eruption, which can cause health risks for humans and animals when inhaled.
• How is Eyjafjallajökull a volcanic example? (Iceland volcano)

  Located on mid-atlantic ridge (constructive boundary)

  
  

  Eruption took place in April 2010 and finally stopped in October.
• What were the impacts of Eyjafjallajökull?

  Ash fallout delayed flights internationally, closed their airport.

  800 people evacuated

  Animals kept indoors

  Roads and schools were kept indoors

  Mudslides occurred due to ice caps melting

  Ice caps melting also caused floods
• What were the responses to Eyjafjallajökull?

  Schools closed to prevent health problems

  
  

  Gaps left in roads / bridges to let meltwater through

  
  

  Animals kept indoors

  
  

  Iceland had the technology to mitigate the hazard and didn't require aid.
• What is the park model?

  A graph split into 4 segments: Pre-disaster, relief, rehabilitation and reconstruction. It focuses more on the improvement of quality of life rather than management strategies.

  
  

  Helps planners know what resources are needed at each stage and how to prepare for any hazards that may occur in the future.

  
• What are the advantages and disadvantages of the park model?

  Advantages:

  Shows if quality of life improves after hazard

  Gives general idea how detrimental the hazard was

  It shows the recovery time

  
  

  Disadvantages:

  Doesn't show what quality of life was like before the hazard

  Doesn't say what kind of hazard it was

  Doesn't take into account of secondary hazards
• What is the risk management cycle?

  It is a model split up into mitigation, preparedness, response and recovery.

  
  

  Mitigation is how the area attempts to minimise the impacts of future hazards.

  
  

  Preparedness looks at planning for the hazard such as planning how they would respond.

  
  

  Response is how people react when a hazard occurs.

  
  

  Recovery is how the area returns back to its normal state

  
  

  It is a cycle as the hazards are ongoing

  
• What are the types of hazards?

  Hydrological -> Floods, avalanches, etc.

  
  

  Geological -> Earthquakes, volcanoes, etc.

  
  

  Atmospherical -> Storms, droughts, etc.
• What is the difference between a natural phenomenon and a natural hazard?

  A natural phenomenon is a natural event that doesn't affect humans where as a natural hazard burdens them in instances such as loss of life, destruction of homes, etc.
• What factors affect how people perceive hazards?

  Socio-economic status

  Level of education

  Economic status

  Religion

  Family situation / past experiences

  Personality
• What is fatalism?


  People believe they were meant to be involved in a hazard and that it was an act of God. They do not try to prevent it as it is part of God's plan.
• What is risk sharing?

  Sharing the costs of reducing hazards so that they are prevented in the future. An example would be people getting insurance so that they are covered and can use the insurance to help any repairs of a damaged house in the event of a hazard.

  
  

  Not everybody is affected so not everyone does claim but everyone does contribute into sharing the costs.
• What is integrated risk management?

  A holistic approach to hazard management. The process involves considering social, economic and political factors in the risk analysis.
• What are the responses to wildfires?


  Short term:

  Putting the fire out

  Waters on roofs to prevent embers setting it alight

  Diverting the fire away from settlements

  
  

  Long term:

  Public education about risks of using BBQ's and campfires in vulnerable areas

  
  

  Emergency plans and emergency supplies of food, water and medicine.

  
  

  Use non-flammable building materials and creating firebreaks in the trees
• What are the impacts of wildfires?

  Deaths / injuries

  Homes destroyed

  Health problems

  Governments can face criticism

  Destroys businesses affecting jobs and the economy

  Cost of fighting the fires are huge

  Habitats and soils are damaged

  Discourages tourists
• What are causes of wildfires?

  Human:

  Bonfires

  Lighting fireworks

  Out of control campfires

  Arson

  
  

  Physical:

  Lightning strikes

  Volcanic eruptions
• What are the types of fires?

  Ground fires - the ground itself burns which is slow, with no flame and little smoke.

  
  

  Surface fire - less litter and low lying vegetation burns which can be of low and high intensity

  
  

  Crown fire - is where fire moves rapidly through the canopy and these are usually fast moving and intense
• What conditions are needed for fires to form?

  Closely sourced trees which allow fires to travel quick.

  
  

  Some trees such as eucalyptus trees have oil in them making them able to catch fire a lot easier and enough fuel to help fire burn for longer.

  
  

  Climate and weather needs to be enough rainfall to be able to grow and create fire fuel. However, need a long period of dryness so material can dry out and catch fire. Strong winds can help.

  
  

  Fire behaviour as fires can creep meaning that they travel slowly whereas running is that they are more intense and spread quicker.
• When and where did the Australia wildfire take place?

  Victoria, South-east Australia in February 2009

  
  

  Followed a 10 year drought and had a heatwave of over 40°c with strong winds.

  
  

  Also had a lack of management, which meant that there was a large amount of oil and fuel and several fires were caused by power lines and arson.
• What were the impacts of the Australian wildfire?

  170+ people were killed

  
  

  Millions of wildlife were killed including rare species such as the spotted frog

  
  

  Damage was estimated to cost around 4 billion

  
  

  2000 homes destroyed
• What were the responses to the Australian wildfire?

  Authorities predicted how the fire would spread and warned locals to evacuate or stay and defend their homes

  
  

  More than 2000 firefighters and volunteers helped put out the fires.

  
  

  400 million was donated

  
  

  Looking to build fire shelters, improving warning systems and improving the emergency evacuation strategy.
• What is the focus?

  The point where pressure releases, the deepness of the focus signifies the damage.

  
  

  The focus does not need to be a single point. For example, it can be a fault line (a weakness in the crust).
• How does the depth of the focus affect the magnitude of seismic hazards?

  Deep focus earthquakes tend to be of a high magnitude. However, they tend to do less damage than shallow as shock waves have further to travel to reach the surface, releasing their power.
• What affects the magnitude of seismic hazards?


  Margin type -> Biggest earthquake occur at destructive plate margins where one plate is subducted. Constructive earthquakes tend to be less severe than destructive and conservative.

  
  

  Rate of movement -> Plates move at different speeds.
• How do landslides/avalanches occur?

  Shaking of the ground can dislodge rock, soil and snow which cause landslides and avalanches that move down slopes very quickly.
• How do tsunamis occur?

  Large waves which are caused by the displacement of large volumes of water. For example, they may be triggered by underwater earthquakes.

  
  

  The waves travel very fast in deep water so they can hit the coast with little warning causing a high death toll such as the Japan tsunami in 2011.
• When and where did the Haiti earthquake occur and what is its characteristics?

  Located in the Caribbean Sea next to the Dominican Republic.

  2010 (January)

  7 on the Richter Scale

  Poorest country in the western hemisphere

  Lies on a conservative plate boundary
• What were the impacts of Haiti?

  300,000+ died

  1.5 Million left homeless

  Millions left without electricity

  70% of Port Au Prince was destroyed (capital)

  Airport was unusable due to damage

  Over 4000 prisoners escaped

  Crime, violence and rape took place in the camps
• When and where did the Japan earthquake occur and what are its characteristics?

  2011, Japan

  
  

  Experienced a Richter 7 earthquake which had a knock-on effect and triggered a Richter 9 earthquake in the sea therefore triggering a tsunami.
• What were the impacts of the Japan earthquake?

  16,000 people died

  
  

  1.5M left without water and 4.4M left without electricity

  
  

  People scavenged the streets (caused looting)

  
  

  Tsunami damaged a nuclear powerplant which caused people to be evacuated and caused a widespread of radiation