CS: Tohoku, Japan Earthquake 2011

Question 1

General

Answer 1

• on March 11th 2011, a 9 magnitude EQ, w a 30km epicentre, struck off Eastern coast of Japan, on main island of Honshu, severely impacting region of Tohoku
• most powerful recorded EQ in Japanese history, + most expensive natural disaster in history (est. $235B)
• Japan is a dev. country, w a GDP of $4.97 trillion

Question 2

What were Japan’s methods of preparedness for the EQ?

Answer 2

• prediction
• hazard mapping
• monitoring
• planning

Question 3

What prediction strategies helped Japan prepare for EQ?

Answer 3

• although EQs + their magnitudes are impossible to predict, bc their strength is random, Japan uses historical data + seismic activity (e.g. frequency + magnitude of EQs) to predict probability of an EQ occurring in specific areas
• seismic gaps, which are areas along a fault line that haven’t experienced recent EQs, are also used as a forecasting method, bc suggests stress is building up, inc risk of an EQ

Question 4

How did hazard mapping help prepare Japan for the EQ?

Answer 4

• Japan used EQ hazard maps, which predict severity + frequency of EQs in specific areas, for land-use planning, to design buildings + dev infrastructure, ensuring they’re resistant to seismic activity

Question 5

How did monitoring help Japan prepare for the EQ?

Answer 5

• Japan’s EQ Early Warning System, which detects initial shock waves, provided Ms of ppl w a few seconds warning, before stronger shacking occurs + so allowed many to evacuate buildings + trains to stop, mitigating impacts
• Japan Meteorological Agency issued tsunami warnings 3 mins after EQ, enabling effective evacuation + response measures that mitigated impacts + minimised casualties
  
  • tsunami warning system involves a network of buoys in ocean, that have sensors to detect offshore EQs + monitor tsunami waves, allowing it to predict areas most at risk + send alerts to these areas

Question 6

What planning strategies helped Japan prepare for the EQ?

Answer 6

• Japan has v strict building codes, in which buildings are designed to be EQ resistant so can withstand intense shaking from EQs
  
  • they’re often designed w strong, flexible frames + shock absorbers, enabling energy to be absorbed + dispersed, so buildings can move w/o collapsing, + strong, deep foundations w reinforced concrete, to stabilise buildings + prevent shifting when ground shakes
  • e.g. in Sendai, >70% of buildings were EQ resistant, helping mitigate impacts
• Japanese gov. ensured public were education on EQ + tsunami safety, by carrying out evacuation drills + campaigns, to inform public ab safety measures like having emergency safety kits
• Japan invested heavily in constructing large sea walls along 14,000km of its coastline, to protect inland from tsunami waves

Question 7

Primary impacts

Answer 7

• EQ generated shock waves that caused severe ground shaking in Tohoku region
  
  • led to heavily damaged, or collapse of buildings + infrastructure in major cities like Tokyo (e.g. 30 homes + buildings were destroyed + 1000 were damaged)
  • caused minor soil liquefaction, resulting in further damage to buildings, roads + infrastructure
  • led to landslides in Mt regions, which buried villages, farmlands + transport routes, further disrupting communication + causing a delay in aid + emergency response
  • caused several nuclear power stations to suffer from fractures, causing them to shut down + lose power
• despite large magnitude of EQ, damage + deaths (ab. 700 ppl) from EQ itself was low

Question 8

Secondary impacts

Answer 8

• EQ triggered a massive tsunami w waves reaching 40m in some areas, + so exceeded protective sea walls built on experience of past smaller tsunami’s
  
  • led to widespread flooding + destruction of infrastructure, resulting in death of 16,000 ppl + injury of 6150 ppl, w 450,000 ppl left homeless from destruction of 12,000 buildings
  • caused a power failure at Fukushima Daiichi Nuclear Power Plant, disabling back up generators needed for cooling reactors, + so led to meltdown of 3 plant reactors
    
    • this released radioactive materials into air + ocean, causing widespread contamination of surrounding areas, + so >200,000 ppl were evacuated from the vicinity

Question 9

How did Japan respond to + recover from the EQ?

Answer 9

• was highly organised + efficient w local gov. + international organisations working together to address immediate needs + ensure sustainable reconstruction
• within hrs of tsunami, rescue workers + 100,000 members of Japan Self-Defence Force were sent to help in search + rescue operations, provide medical care + deliver supplies
• those evacuated from areas surround Fukushima Daiichi nuclear meltdown, had radiation lvls checked + health monitored, + many were given iodine tablets to stop radiation poisoning
• although rebuilding took yrs, affected areas were rebuilt w stronger infrastructure + stricter measures to improve Japan’s preparedness for future disasters

Question 10

Conclusion/Evaluation

Answer 10

• although Japan was relatively well-prepared for EQ, sheer scale of event revealed limitations in its disaster preparedness systems, highlighting that even sophisticated plans can be insufficient when facing such extreme natural disasters
• however, Japan was successful in mitigating impacts + diverting social impacts to eco. impacts
• also, this led to further strengthening of Japan’s preparedness + disaster planning, ensuring resistance is improved for future natural disasters