Japan Tohoku earthquake case study

Question 1

Where is Japan located?

Answer 1

An AC in eastern Asia, in the Pacific
Pacific plate subducting beneath the Eurasian plate at a convergent plate boundary just east of Japan - ever-present risk of tsunamis due to movement of plate boundaries just offshore

Question 2

When did the earthquake occur and what was its magnitude?

Answer 2

March 21st 2011 100km of the coast of Japan, magnitude 9.0 - largest ever recorded in Japan - caused the Earth to shift on its axis. Lasted 6 minutes (a very long time for an earthquake - Haiti’s lasted less than 1 minute)

Question 3

Give some more information on the earthquake

Answer 3

Caused large parts of Japan’s eastern coastline to drop by up to 1m (lowering the height of tsunami walls)
Caused a tsunami that reached heights of up to 40m when it reached the coast, and travelled up to 10km inland (parts of Japan’s coast is very flat so the tsunami kept moving inland)
Over 500 aftershocks

Question 4

What were the impacts on people?

Answer 4

Impacts caused by tsunami are secondary (tsunami itself was a primary impact)
Killed nearly 16,000 (2/3 over 60 years old, 90% due to drowning)
Injured 6000 more
Problems disposing of dead bodies as crematories, cemeteries, morgues and power infrastructure were destroyed - mass graves to prevent spread of disease
100,000 children separated from families - up to 2000 orphaned
Infrastructure destroyed - including schools, hospitals, health centres, as well as roads and transport infrastructure

Question 5

What were the economic impacts?

Answer 5

Estimated costs of the earthquake, including reconstruction - £181 billion
45,000 buildings destroyed, 145,000 damaged, 230,000 vehicles destroyed or damaged
15 ports destroyed or damaged - disrupting trade and flows of goods
4.4 million houses and many businesses lost electricity (shutdown of 11 nuclear reactors major cause)
2 oil refineries set on fire during earthquake
Train services badly disrupted
25 million tonnes of debris - expensive clean up
Stock market for Japanese businesses (e.g. Sony, Toyota, Panasonic) dramatically fell

Question 6

What were the environmental impacts?

Answer 6

Fukishima nuclear power plant explosion after reactors were flooded - radioactive contamination - soils in surrounding countryside, including farmland, contaminated - 30km evacuation zone around plant
2 oil refineries set on fire
110,000 nesting birds drowned in a wildlife reserve in Midway Atoll (a pacific island) as a result of the same earthquake

Question 7

What were the political impacts?

Answer 7

Japanese government put billions of yen into the economy to bring some stability - increased government debt at a time when reduction was a prime political aim
Popular movement against nuclear power - concerns over safety standards and regulation of the nuclear industry
Political fallout from Fukishima nuclear accident across the world - some anti-nuclear organisations used the incident to support their arguments

Question 8

How was/is vulnerability mitigated?
(Japan’s economic wealth, highly developed education system and stable political environment enable it to cope with the constant threat of high magnitude earthquake events

Answer 8

Research and monitoring - Japan Meteorological Agency (JMA) provides information and warnings of impending earthquakes and tsunamis
Detailed disaster planning involving a wide range of organisations, e.g. governments, medical services, fire, military, transport, power and telecommunications companies
Buildings with aseismic design - counter weights, base isolators etc.
Suspension bridges capable of movement (rather than rigid in design)
Flexible joints in underground utility pipes (gas and water)
Fire-proofing older wooden buildings, common in old districts of Japanese cities
Land-use zoning that provides open spaces where people can assemble after and earthquake (buildings kill people)
Controlling building in locations susceptible to liquefaction or excessive ground shaking
Tsunami warning systems off the coast
Community preparedness - ongoing education, training and earthquake kits

Question 9

How was loss modified?

Answer 9

Vast resources to manage losses caused by earthquakes
Well rehearsed recovery and reconstruction plans, at national, regional and local levels - can be actioned immediately following an earthquake. Aim to rebuild physically, economically and socially as quickly as possible.
Strategies constantly being updated - impacts of earthquake disasters in the short term are more serious and longer-lasting