Hazards

• Crust


  Earth's outermost layer.
• Mantle


  The layer of hot, semi-molten rock between Earth's crust and core.
• Outer core


  Liquid iron and nickel
• Inner core


  The solid ball of iron and nickel at the centre of the earth
• Continental crust


  Crust that is 30-50 km thick and less dense
• Oceanic crust


  Crust that is 5-10 km thick and more dense
• Tectonic plate


  Sections of the Earth's crust that move due to convection currents.

  
• Destructive margin


  Where two plates move towards each other. When this happens with a continental and oceanic plate, the denser oceanic plate is pushed underneath the less dense continental plate, creating volcanoes and ocean trenches. If this happens to two continental plates, a folded mountain range is created

  
• Constructive margin


  Where two plates move away from each other, causing magma to rise from the mantle and fill the gap, creating new land

  
• Conservative margin


  Where two plates move sideways past each other, or at different speeds in the same direction. Crust isn't created or destroyed.

  
• Volcanoes


  Found at destructive and constructive plate margins and hotspots in the mantle (e.g. Hawaii)

  
• Earthquakes


  Found at destructive, constructive and conservative margins

  
• Formation of volcanoes at destructive plate margins

  When the oceanic plate sinks beneath the contintal plate and melts. This creates magma which then rises up through cracks in the earth called vents and erupts out forming a volcano
• Formation of volcanoes at constructive plate margins

  Magma rises into the gap created by the plates movinv apart and a volcano is formed
• Cause of eathquakes


  When plates move, and eventually jerk past eachother, it sends out shock waves that are the earthquake
• Epicentre


  The point on the Earths surface straight above the focus

  
• Focus


  The point in the Earth where the earthquakes start. This is where the shock waves are stongest
• Moment magnitude scale


  The measurement of an earthquakes strength
• Primary effects of earthquakes

  Buildings and bridges collapse; people injured/killed by collapsed buildings; infrastructure is destroyed; electricity, gas, water and communication networks are cut off
• Secondary effects of earthquakes

  Earthquakes trigger landslides and tsunamis; leaking gas can be ignited; people are left homeless and may die; shortage of clean water; lack of sanitation; aid can't be provided if roads are blocked; unemployment; reduced tourism; expences
• Immediate responses to earthquakes

  Rescue people who are trapped; recover dead bodies to prevent disease; extinguish fires; set up temporary shelters; provide temporary supplies; foreign countries and charities send aid workers, supplies and money; record damage.
• Long-term responses to earthquakes

  Re-house people; repair and rebuild damaged buildings, roads, railways and bridges; reconnect broken electricity, water, gas and communications connections; improve building regulations; set up initiatives to provide economic recovery
• Primary effects of volcanoes

  Buildings and roads are destroyed by lava flows; ash causes roofs to collapse; people and animals are injured/killed by lava and falling rocks; crops are damaged; water supplies are contaminated; people, animals and plants are suffocated by volcanic gases
• Secondary effects of volcanoes

  Mudflows form as volcanic materials mix with water; flooding is caused as ice and snow is melted; transport networks are blocked or destroyed; people are left homeless; tourism decreases during the event but can increase afterwards; ash makes fields more fertile; recovery can cost lots
• Immediate responses to volcanoes

  Evacuation; provision of food, water and shelter; medical aid; rescue stranded people; provide temporary electricity, gas and communications; foreign aid; record damage
• Long-term responses to volcanoes

  Repair and rebuild buildings, roads, rail, power lines, communication networks; improve, repair and update monitoring equipment; attract tourists to boost the economy
• L'Aquila, Italy earthquake


  A case study earthquake in a HIC that happened on the 6th April 2009

  
• 6.3


  Magnitude of the L'Aquila earthquake
• 300


  The number of deaths of the L'Aquila earthquake
• 1500


  The number of injuries of the L'Aquila earthquake
• Tens of thousands


  The number of buildings destroyed or damaged in the L'Aquila earthquake
• 60,000


  The number of people made homeless from the L'Aquila earthquake
• Primary effects of the L'Aquila earthquake

  People were injured and killed; buildings were damaged and destroyed; people were made homeless; a bridge near the town of Fossa collapsed; a water pipe was broken near the town of Paganica
• Secondary effects of the L'Aquila earthquake

  Aftershocks caused more damage and hindered rescue efforts; fires; the broken water pipe caused a land slide; electricity and phone services were interrupted
• Immediate responses to the L'Aquila earthquake

  Camps were set up for people made homeless; ambulances, fire engines and the army rescued survivors; cranes and diggers removed rubble; free phones and SIM cards were provided; the goverment provided money to pay for rent; gas and electricity bills were suspended
• Long-term responses to the L'Aquila earthquake

  New settlements were built to accomodate over 20,000 residents of the damaged city centes; most of the city centre is being rebuilt; investigations into why modern buildings were not built to withstand earthquakes
• Reasons to live close to tectonic hazards

  It's where their family and friends are; jobs in the area; confident in government support in case of disaster; don't think a disaster will happen; volcanoes create fertile soil; volcanoes provide tourism

  
• Monitoring of earthquakes


  Networks of seisometers and lasers are used to monitor the earths movement
• Monitoring of volcanoes


  Small earthquakes, escaping gas and bulges in the earth are recorded
• Prediction of earthquakes


  While they can't be reliably predicted, monitoring caan be used to forcast areas in danger