seismic & multi hazardous environment - TOHOKU Flashcards
how many EQ on average does japan have annually
1500
accounts for 1/3 of the worlds total
order of events EQ and tsunami
- moved the entire island of Honshu 2.4m closer to North America
- shifted the Earth’s axis approx. 10cm
- made earth days shorter by 1.8 microseconds
- calved 125 km2 of iceberg from Antarctica’s coast
- caused visible waves in Norwegian fjords
time, date, location and size of EQ
2.46pm
Friday 11 March
mag. 9.0 EQ
occurred under the Pacific Ocean
why did it happen
a segment of the North American plate that had been dragged down by the subducting Pacific Plate, slipped upwards between 5-10m.
what did the EQ cause
this displaced water resulting in a tsunami at hundreds of km/h
when and where did the first wave hit
1st wave hit the NE coast only 30 mins after the EQ
how many waves were there
10
how far apart were the waves
each 1km apart
as they reached shallower water, they slowed and piled up,
reaching 10m in height.
what did the waves do to the tsunami defence walls
they overwhelmed tsunami defence walls and surged up to 10km inland.
what impact did ground shaking have
buildings collapsed, some set ablaze by broken gas and petrol pipes
when the tsunami swept inland what happened
caused devastation to boats, buildings, vehicles and trees
flooded an area of 500 square km
what happened when the water receded
whole cities were in ruins
trains had vanished
ships and boats had been moved
what happened in tokyo - skyscrapers
in Tokyo, skyscrapers started ‘shaking like trees’ = EQ proof design meant damage was limited
sendai
areas near the sea were badly damaged, but the city centre was largely unaffected
rikuzentakata
almost completely submerged and was almost totally destroyed
minami-sanriku
half the population of 17,000 died
few buildings left standing
how many dead/missing and why
18,000 + were dead/missing, mainly due to the tsunami, although the Japanese tsunami system saved many lives.
how many made homeless
½ million people
what social impact did it have
200,000 children now suffer from precancerous thyroid abnormalities, primary nodules and cysts.
how many lived in shelters for weeks
150,000+
how many homes left without running water
1 mill +
how many homes left without electricity
6 million
there were shortages of x, y, z
food, water, petrol and medical supplies
what happened 2 weeks post EQ
there were more than 700 aftershocks, causing concerns and further damage.
what happened to the fukushima daiichi power plant
explosions and radiation leaks at the Fukushima Daiichi nuclear power plant in the days after the EQ spread fear around the world.
EQ severed the power supply to the
cooling system.
tsunami then destroyed the backup generators.
workers struggled to prevent the meltdown.
what conditions did survivors live in post disaster
in freezing temperatures, survivors huddled in shelters and hoarded supplies as rescue workers searched the coastline of submerged homes.
how many soldiers helped and what did they help do
100,000 soldiers were mobilised to establish order, organised rescue work and distribute blankets,
bottled water, food and petrol.
what did the uk send to aid the process
63 search and rescue specialists
two rescue dogs
a medical support team
where was an exclusion zone set up
an exclusion zone was set up around the Fukushima Daiichi nuclear plant.
homes were evacuated and iodine tablets were distributed – to prevent radiation sickness.
who coped well with the EQ
japan
what was wrong with japans defence system
tsunami defences were inadequate against the height and force of the water.
what will be done in the future to improve japans defence systems
future planning must consider whether
defences should be built to defend the coast against similar high magnitude, low frequency event.
special zones for reconstruction were designated with relaxed planning regulations to encourage
rapid rebuilding and tax incentives
what did japan do in 2013
they unveiled a new upgraded tsunami warning system because many people had
underestimated their personal risk and/or assumed that the tsunami would be as small as others previously experienced.
what happened after the chernobyll incident in 1986
thyroid cancer cases among children started to increase rapidly after four to five years had passed.
some are of the opinion that because of the Fukushima disaster, a similar increase in the incident of juvenile thyroid cancer
may occur.
how much did the damage cost
estimated at $300 bill. making it the most
costly disaster in history
tsunami
a major secondary consequence of the Tohoku earthquake
magnitude of foreshock 2 days before the major earthquake
7.2
how long did it take to repair a motorway damaged by the tsunami
6 days
what plat boundary caused the EQ
destructive/convergent
date of the earth quake
9 march 2011
distance of the coast of japan from the epicentre
70km
what powerplant was badly damaged and was releasing radiation
fukushima
what % of Japan has sea walls; but they were too small for the tsunami
40%
