Tsunamis Flashcards
How do tsunamis happen?
Tectonic activity causes water to be displaced.
A wave starts from where the water was displaced before moving outwards.
What are the consequences of tsunamis?
Tsunami waves do not ebb and flow like normal waves - they travel far inland before retreating.
Tsunamis can surge up to 30 m high and cause devastation when they hit land.
How high can tsunamis reach?
Up to 30m
What caused the Japan tsunami?
There was an earthquake with a magnitude of 9.0 in northeast Japan on the 11th March 2011.
The earthquake is known as the Tohoku earthquake.
What were the primary impacts?
1 million buildings were damaged and over 120,000 buildings were completely destroyed.
Many buildings sunk into the ground because of liquefaction, which is when waterlogged soil acts like a liquid.
What were the secondary impacts?
The tsunami that was caused by the earthquake caused thousands of deaths (it is hard to know how many people died in the earthquake or the tsunami and lots of people are still missing.
More than 150,000 people became homeless and in 2017, 6 years on, 50,000 people still had no homes.
The tsunami damaged the Fukushima nuclear power station. Electricity could no longer reach Fukushima and there was a nuclear meltdown at the plant, releasing toxic nuclear waste into the local area.
Railways lines were destroyed by the tsunami.
What was the long term impact and response?
Economists estimate that the total damage done by the earthquake and tsunami is $200 bn. This is the largest amount of damage caused by any natural disaster ever.
Japan was a high income country and had a new tsunami warning system. But, studies suggest that only 58% paid any attention to the tsunami warning.
In the 12 months after the Tohoku earthquake, there were 5,000 aftershocks in Japan.
What was the magnitude of the Japan earthquake?
9.0
