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Seismic hazards - Coggle Diagram

- - - - Large concrete counter weight
      - shock absorbers
      - Cross bracing
      - Retro fitting of older buildings
- - - - A segment of the North American plate shifted upwards between 5 and 10 metres sending tsunamis travelling in all directions at 100 km/h
      - Japan's Tsunami warning system kicked in along the 3000km stretch of the coastline but only gave people minutes to escape
      - there were 10 waves each around 1km apart and they overwhelmed the tsunami defence walls
  - - - Ground shaking caused buildings to collapse and some were set ablaze by broken gas and petrol lines
      - The Tsunami swept inland mainly along the North East coast and obliterated everything in its path
      - flooded an area of around 500km
      - In Tokyo the skyscrapers started shaking like trees however the earthquake proof design meant that damage was limited
      - over 18 000 dead or missing mainly due to tsunami, although the warning system saved many lives
    - - Half a million people were homeless
      - 1 million homes without water and 6 million without electricity
      - shortages of food, water, medical supplies and petrol
      - Fukushima power plant
        
        The fukushima power plant became overwhelmed when the tsunami waves had breached the sea walls that were thought to be indestructible. The earthquake severed the cooling system and power supply and the tsunami destroyed the back-up generators
        
        Fears of a nuclear meltdown caused panic-selling across global stock markets
  - - - Helicopter crews plucked survivors from rooftops and flooded farmland
      - 100 000 soldiers were mobilised to establish order and aid essential supplies
      - an exclusion zone was set up around the power plant - effects of this hard to measure
      - no reports of looting or violence
    - - Japan coped well with the high magnitude earthquake but the tsunami defences were inadequate to cope with such monstrous waves
      - Future contingency planning must consider whether defences should be built against a similar high magnitude, low frequency event
      - in 2013 there was a new upgraded warning system
      - The Japanese government set up an advisory board called the reconstruction design council
      - 5 years after the fukushima explosions 100 000 residents have still not returned home
      - the total cost was around 300 billion dollars which makes it the most costly natural disaster ever, Japan was already heavily indebted and this repair bill had to be met with more borrowing
- - - - effective warning systems do exist for example in hawaii which gives hours of warning following different levels of seismic events
- - - - Destructive plate margins have the largest magnitude earthquakes
        
        deeper focus earthquakes higher mag less damage