Tsunami case studies Flashcards
What is the plate tectonic background of the 2011 Japan tsunami? 4
RICH.
- 3 tectonic plates - Eurasian, Pacific and Philippines - DESTRUCTIVE boundary.
- 7.2 earthquake on the 9th of March, 2 days before the 9.0 magnitude earthquake of the 11th.
- Large sized aftershocks - 6.0.
- Focus - underwater depth of approx. 32 km.
Why did the 2011 Japan tsunami happen?
Stress build up - Pacific plate subducted under the Eurasian plate.
Pressure released as earthquake waves.
Eurasian plate was warped as the Pacific plate descended.
Strain energy released - Eurasian plate bounced back upwards.
Water displacement above in the Pacific Ocean - tsunami wave.
Megathrust earthquake.
How vulnerable was Japan regarding the 2011 tsunami? 4
- Japan - 30% of the world’s earthquakes every year.
- Upper 10m of the soil - vulnerable - waves amplified in this soil/caused liquefaction.
- The Fukushima nuclear power plant also faced directly the epicentre of the Earthquake.
- Vulnerable coastline - vast majority live on the coast.
What is Japan’s ‘capacity to cope’ like? 4
- 40% of Japan’s coastline - 10m high sea walls.
- JMA detected the earthquake/issued TV warnings after rapid P-waves that arrived, but before more damaging S waves.
- Tsunami predicted just 3 minutes after the major earthquake - 20 minutes to get to safety.
JMA broke this news on live television.
Messages went out on Japan’s mobile network. - Specially designed buildings.
What was Japan’s institutional capacity like? 6
- Quick emergency response from the army and aid workers.
- Buildings are earthquake proof.
- Japan population are taught yearly on the 1st September on earthquake education.
- Big GDP; $34,000 in 2011 – more planning.
- JMA has 200 seismographs and 600 seismic intensity meters.
- Earthquake occurs - JMA sends the epicentre, magnitude and observed seismicity information.
What were the social impacts of the 2011 Japan tsunami? 7
- 12,000+ died.
- 2,000 injured.
- 530,000 displaced.
- 4,700 damaged homes.
- 500km2 coastal plains hit, destroying farmland, settlements and communications.
- Ruptured gas pipes led to fires.
- Harbour boats were destroyed.
What were the economic impacts of the 2011 Japan tsunami? 4
- £90 billion lost in shares.
- The World Bank estimated cost was US$235 billion.
- Insured losses - $14.5 to $34.6 billion.
- 10% of the fishing ports were damaged.
What were the environmental impacts of the 2011 Japan tsunami? 2
- Dam north of Fukishima burst its banks.
2. Radioactive materials escaped; radioactivity levels increased by 40,000 times (long term impact on health).
What was the short term response to the 2011 Japan tsunami like? 6
- Reasonably good reaction response.
- Tsunami reaction response – 20 minutes didn’t allow enough time for evacuation.
- JMA did a good job of monitoring and warning people – helped saved lives.
- Japanese government sent in the specially trained Self-Defence Force.
- Japanese Red Cross reported $1 billion in donations.
- 100,000 started a rescue relief mission.
What was the long term response to the 2011 Japan tsunami like? 3
- The Bank of Japan offered 15 trillion Yen (US$183 billion) to the banking system to normalize market conditions.
- The government reviewed predicting methods, as well as improving sirens and communications.
- The flood gates and Tsunami walls were also questioned.
What is the background of the Indian Ocean 2004 tsunami?
POOR. Indo-Australian subducts under the Eurasian plate. Boxing Day 2004. 9.0 magnitude. 25km wave in height.
What are the social impacts of the Indian Ocean 2004 tsunami? 7
- 300,000 died.
- Tens of thousands injured.
- Tourist destinations - hundreds dead/missing from Europe.
- 1,500 villages destroyed.
- Fear of disease e.g. cholera from contaminated water.
- 5 million homeless.
- Fear of disease led to rapid burials/burnings - limited outbreaks.
What are the economic impacts of the Indian Ocean 2004 tsunami? 4
- Tourist infrastructure damaged e.g. hotels.
- Coastal communities/economies damaged.
- $5 billion total cost.
- 60% of the fishing fleet/industrial infrastructure in Sri Lanka’s coastal regions were damaged.
What are the environmental/political impacts of the Indian Ocean 2004 tsunami? 3
- Lots of medical aid.
- Contaminated water by salt water.
- Damaged ecosystems e.g. mangroves.
What were the short term responses of the Indian Ocean 2004 tsunami?
Western side - warning was received.
E.g. Kenya reacted quickly - moved thousands off beach.
Broken communication links - poor aid distribution.
World Food programme - food aid to 1.3 million.
$7 billion promised for damaged regions - but problems delivering financial help.
March 2005 - the Asian Development Bank reported promised $4 billion hadn’t been delivered.
Sri Lanka - had received no foreign government aid.
British public donated £330 million.
