hazardous earth 4 - tohoku Flashcards
physical and human setting of japan
physical: convergent boundar: pacific subducting underneath eruasian, reverse fault. March 11th 2011 2:46pm = earthquake time, 9.0 on richter scale,shallow focus of 24 km, epicentre = 80 miles east of sendei, submarine earthquake, 420 aftershocks for 5 weeks afterwards
HUman: HDI: 0.9 (ranked 17), GDP = $41,300, 94% people inurban areas, literacy rate of 99%, population of 120 million
hazards
1 - ground shaking and liquefactionL soil liquefaction occured in areas around Tokyo, damagin >1000 buildings. 420 aftershocks afterwards in 5 weeks after earthquake.
2 - tsunami: warning issues 3 minutes after the EQ, travelled oevr 500 mph and reached coastline within 20-30 minutes, waves were 15 metres high and it travelled 8 miles inland. Arrived in California after 11 hours with 2 metre high waves. 95% of deaths due to drowning.
3 - nucleardisaster:Fukushimaa nuclear plant reactors automatically shut down, but it went into meltdown when supplies of old water were blocked by debris. The failed cooling system caused nuclear fuel rods to melt, 4/6 reactors damaged.
impact of the earthquake
economic: 300,000 buildings destroyed, erthquake cost of $300 billion, caused a 3.5% drop in GDP, most expensive natural disaster in history, shipping disruped, waves affected california: $10 millionin damage, by june over 200 companies forced into bandrupcy.
environmental: shut down nuclear plants for maintainence and improtted fossil fuels: wont meet kyoto targets, radiation in atmosphere, flooding due to tsunami, transported sediment 5km inland blocking roads.
political: protests about nuclear plants, international debate over nuclear plants led to germany closed all its nuclear plants, kyoto targets not met.
social: 20,000 died, 6000 injured, 90% of deaths due to drowning, 140,000 within 20km of nuclear evacuated, 500,000 homeless.
mitigating the vulnerability
strengths: early warnign system on bullet trains stopped bullet trains before the shaking by detecting P waves - over 1000 seismometres used for it. Aseismic building design: 87% of Tokyos buildings built to withstand earthquakes via base isolaters, Tokyo skytree has a 500ft core column. Japan has lots of historical data and uses hazard planning maps so important bildings e.g. hospitals and schools arent destroyed. Pacific tsunami warnin centre in Hawaii has buoys across pacific ocean to detect Eqs and send warning via satellites.
limitations: 10 metre high seawall failed to prevent 15m waves, fukushima failed, aseismic desgin is ver expensive: $600 million for a core column.
mitigating the losses short term
strengths:
- within 30 min, 11 military aircraft deployed, 140,000 within 20km of Fukushima evacuated. JSDF moved in on the ground and within 2 days all debris was cleared
- 163 countries including LIDCs offered assistance, as of march 2012, donations to affected areas otalled 520 billion yen, almost a million assisted in recovery efforts.
- 500,000 in evacuation shelters within days of disaster, construction of temporary shelters started, therapists and social workers also dipatched.
weaknesses:
- bodies buried in mass graves as quickly as possible to reduce disease spread. Evaciuation shelters inadequater comfort, temps fell to -4 degrees C, shelters were damp due to flooding.
mitigating the losses long term
strengths:
- the priority was reopen transport, within a fortnight expressway was repaired and reopeed, sendai airport was reusable within 3 weeks.
- Japanese gov set up reconstruction design council to plan a long term strategy for a stronger economy and society- budget of 23 trillion yen
- wihin 6 months, 96% electricity restored. 98% of water supply and 99% of landline networks restoyred. HOme owners can buy earthquake insurance now.
weaknesses:
- 6 months later the port was operating at onl 68% of capacity.The japanese governments reconstruction design council meant budget was very exppensiver and caused debt.
