Tsunami casestudies

When was japan tsunami

11th March 2011

what time was japan tsunami

2:46pm

plate boundary that happend for japan

subduction of the pacific plate under the eurasian (destructive)

How long was JP earthquake

2 minutes

how far was the epicentre from the coastline (JP)

72km

How deep was JP’s focus

24km

How long did it take for the tsunami to develop and innundate the coastline JP

20 minutes

How many aftershocks did JP face 5 weeks after the disaster

420 aftershocks greater than 5.0

Political/human factors explaining the high vulnerability of the area JP

Prime minister had accepted that the gov. was “too complacent” and had come to believe in technological infability

How many died in Jaoan

20,000

What agegroup where 65% of the dead from

over 60

What is Japan’s GDP per capita in 2011

$48,700

Interesting note on Japan’s GDP per capita post tsunami (?)

in 2013, it fell by 9,000 USD - downward pattern… possible after-effects from the damage to supply chains?

Physical factor influencing Japan’s vulnerability (related to earth’s crust)

Near Sendai, the crust is oceanic and very old - therefore cool and dense. Assumed that it would readily slide into the mantle, so only small earthquake prediction

How was the physical factor an example of misjudgment (JP)

Poor research/assumptions lead to further damages, prevailing pattern for the JP tsunami.

How did the pacific plate’s shape influence the sixe of the earthquake

It is warped/got warped and so got stuck rather than sliding smoothly, building strain/pressure

What % of JP is mountainous, and what does this mean for vulnerability

70% is mountainous; urban and industrial development is forced into narrow, lowlying coastal areas

How has the urbanisation of japan impacted the vulnerability of areas

Reclaiming land (creating new land from oceans/riverbeds). This land is very soft and susceptible to ground shaking, causing land slides

Political human factor influencing the extent of the impacts (JP)

Prime minister verbally accepted gov. officials were too complacent; too reliant on ‘technological infalability’

What was significant about Otsuchi (most heavily affected town)’s impacts

Many of the disaster relief officers were killed, proving near impossible to set up recovery op for a week.

Example of industrial supply chain affected (JP)

6 sony factories shut down, losing $2.6 billion

Physical secondary hazard generated from the earthquake (JP)

Landslides were triggered from the steep slopes, causing ‘slope failure’ (collapse) of flood/earth walls

How was the reclaimed land in Japan affected from the earthquake

It suffered liquefaction on the soft alluvial plains.

How many of Japan’s estimated 20,000 deaths were from the original earthquake alone

1,000

What did the Japanese predict for the tsunami and earthquake

Predicted a magnitude 7.5 earthquake and 4-5m tsunami

What was Japan’s magnitude

9.1

How large was Japan’s tsunami

almost 40 metres

What was the tsunami wall that JP built prepared for

Tsunami wall was 8m high. Prepared for 4-5m tsunami (IRL it was 10m)

What was the overall success of Japan’s preperations

• local communities were prepared to an extent with drills & programs.

• Vertical evacuation in Sendai saved many lives

• JP Early warning system provided up to 90 seconds warning for SOME tokyo residents

What did some schools in Kamiashi do

evacuated 3000 children to high ground before hearing official alerts