A Level Geography - Severity of the Impacts of Tsunami

Assess the severity of the various impacts of tsunami (12 marks)

A tsunami is a series of waves from the sea which are triggered by an earthquake, landslide or volcanic eruption. A sub-marine earthquake can cause a tsunami due to the sudden release of pressure when one plate subducts. The uplifted fault leads to the water column to be displaced which leads to waves radiating in both directions. They increase in height as the water gets shallower and can reach 600mph.

Perhaps the most severe impact of a tsunami is the degree of coastal development and its proximity from the coast as this can lead to the destruction of infrastructure. If roads and services are affected, it can drastically change how quickly the most in need receive help. Destroyed hospitals and roads makes it extremely difficult for the affected country to send help, and so it is forced to rely on an overseas ally to provide aid. This may also be a struggle, as tsunamis can wipe out communication systems which may make it difficult for countries to identify the areas most in need. As well as the effects on people, it can also affect the country as a whole as it can costs billions of dollars to fix. It can also take a lot of time to heal the country back to it's original status as the damage could, potentially, be very bad. These problems which stem from the destruction of infrastructure make it the most severe impact.

In addition to this, the wave amplitude can make the impacts of a tsunami a lot worse. The height can greatly affect how many people can find safety as it may be harder to flee. It can put places further in land at risk also, which makes it increasingly difficult to reach a place which is safe. Tall waves can wipe out towns and cities easily as they have great strength and can leave thousands without a home. The Boxing Day tsunami in 2004 left 1.7 million people homeless as the wave was able to pick up buildings and wash them away with ease. This is a severe impact of a tsunami as it can reverse the development of an area in a matter of seconds and can leave a country rebuilding for years and years.

Thirdly, the timing of a tsunami can greatly affect a place. The impacts of a tsunami are likely to be a lot worse if it strikes during the night. This is because many people are asleep and will therefore not be aware of warnings. People may struggle to find safety before the tsunami hits which can leave many stranded and stuck in their homes. Locals will have very little time to prepare and get to safety which will means that many more people will die. The time the tsunami hits can heighten it's severity as thousands of lives can be lost which can affect the working population and the emotional state of families.

The physical geography of the coast can affect the severity of the tsunami, however it does not have as many devastating effects like shown above. The shape of the ocean floor can, sometimes, lessen the power of a tsunami as some of the force can be taken away due to the geography of the ocean floor. Chasms and islands can deflect tsunami waves in some places around the world which would lessen the severity when it hits land.

Similarly, amount of natural defences can reduce the severity of a tsunami, but it will not stop the tsunami from hitting. Although coral reefs and mangroves can lessen the severity of a tsunami, it will only reduce some of the power and will not stop the tsunami from affecting coastal regions. People will still lose their possessions and could lose their homes and livelihoods, so destroying these natural defences is of lesser importance.

To conclude, perhaps the most severe impact of a tsunami is how much infrastructure is affected. This can have long term effects which can be very expensive to fix and put right. More generally, the size and strength of the tsunami wave causes the most severe impacts as it can affect a larger amount of people and can greatly affect how quickly people get to safety.