Tec

• What is a hazard?

  A potential threat to human life and property
• How does an event become a hazard?

  It must be a threat to people
• What is an example of a situation where a hurricane is not a hazard?

  When it hits an uninhabited desert island
• What differentiates a disaster from a hazard?

  A disaster occurs when a vulnerable population is exposed
• What is a hazard?

  A potential threat to human life and property caused by an event
• How does a hazard differ from a natural disaster?

  A disaster will only occur when a vulnerable population is exposed to a hazard
• What are the three major types of geographical hazards?

  Geophysical, atmospheric, and hydrological
• What is a hydrometeorological hazard?

  A hazard that is both atmospheric and hydrological in nature
• What factors affect how people perceive hazards?

  Wealth and experience
• How can wealth affect a person's perception of hazards?

  Wealthier people may perceive a hazard as smaller as they are less vulnerable, but also view it as greater due to risk of property damage and financial loss
• What are the stages of the hazard management cycle?

  Preparedness, response, recovery, and mitigation

  
• What are some questions that can be used to evaluate the effectiveness of hazard models?

  Can they be applied to every hazard? Do they account for level of development and timeframe? Are they vague or could they be improved to account for climate change?
• What are the main components of the Earth's structure?

  Inner core, outer core, mantle, and crust
• What is the asthenosphere and how does it relate to plate tectonics?

  The asthenosphere is a semi-molten layer of the mantle that constantly moves due to convection currents, which drive the movement of the overlying lithospheric plates

  
• What are the three main types of plate boundaries?

  Destructive, constructive, and conservative

  
• What type of landforms are created at a destructive plate boundary where an oceanic and continental plate meet?

  Deep ocean trenches, fold mountains, and composite volcanoes

  
• How does sea floor spreading provide evidence for plate tectonics?

  Paleomagnetism shows symmetrical bands of rock with alternating magnetic polarity on either side of constructive plate boundaries, indicating the plates are moving apart and new crust is being formed
• What is a hotspot?

  An area of volcanic activity not related to plate boundaries, caused by a plume of hot magma rising from the mantle
• What are some of the hazards associated with volcanic eruptions?

  Lava flows, lahars (mudflows), glacial floods, tephra (ejected rock), and toxic gases
• What factors influence the viscosity and explosiveness of volcanic eruptions?

  The amount of silica in the lava - higher silica content makes the lava more viscous and leads to more explosive eruptions
• What are the key differences between the three main types of plate boundaries?

  Destructive:

  • Plates converge, one subducts under the other
  • Forms deep ocean trenches, fold mountains, volcanoes

  
  

  Constructive:

  • Plates move apart, new crust is formed
  • Forms rift valleys, underwater volcanoes, sea floor spreading

  
  

  Conservative:

  • Plates slide past each other horizontally
  • No new crust formation, but can cause earthquakes and faulting

  
• How does the process of sea floor spreading work?

  • At constructive plate boundaries, magma rises in the gap between separating plates
  • This new magma cools and solidifies, forming new oceanic crust
  • The new crust pushes the older crust away from the boundary, causing the seafloor to spread
  • This creates symmetrical bands of rock with alternating magnetic polarity on either side of the boundary
• What are the forces that influence plate movements at convergent boundaries?

  • Ridge push: Gravity acting on the higher elevation at the plate boundary pushes the plates apart
  • Slab pull: The subducting plate pulls the rest of the plate down with it, causing further subduction

  
• How do hotspots form and what features are associated with them?

  • Hotspots are areas of volcanic activity not related to plate boundaries
  • They are caused by plumes of hot magma rising from the mantle and burning through the crust
  • This can create volcanoes and chains of islands as the plates move over the stationary hotspot
• Where do volcanoes typically occur?

  On plate boundaries and hotspots
• What are the primary hazards associated with volcanoes?

  Lava flows, lahars, glacial floods, tephra, toxic gases, acid rain, pyroclastic flows
• How does lava viscosity affect its flow?

  Higher viscosity makes lava flow slower
• What causes lahars?

  Melting ice at high latitudes
• What are jökulhlaups?

  Glacial floods caused by melting ice
• What is tephra?

  Rock ejected by a volcano
• Why can CO₂ be toxic during eruptions?

  It can replace oxygen due to its weight
• What causes acid rain during volcanic eruptions?

  Release of sulfur dioxide into the atmosphere
• What are nuées ardentes?

  Clouds of hot ash and gas
• What is the average speed of pyroclastic flows?

  Around 60 mph
• What does the Park Model represent?

  Human responses to hazards over time
• What does the steepness of the Park Model curve indicate?

  How quickly an area deteriorates and recovers
• What is the first stage of the Park Model?

  Relief
• What happens during the relief stage of the Park Model?

  Immediate local response and foreign aid appeal
• What is the second stage of the Park Model?

  Rehabilitation
• What occurs during the rehabilitation stage?

  Restoration of services and temporary shelters