Japan Earthquake and Tsunami 2011

Thursday, 26 November 2015

Minimising Damage and Risk

Minimising Damages:

Damage to buildings is a concern of all earthquake prone areas and new technology and policy has been introduced in Earthquake prone areas to attempt to keep buildings and other infrastructure from collapsing, which would cause casualties in cities if buildings began to collapse.

Regulations and Earthquake Resistant Buildings:

Regulations are an important part in combating casualties from infrastructure. Areas such as Japan have strict rules on the reinforcement that needs to be implicated for buildings of certain heights. This minimises the effects that earthquakes have on buildings and also keeps the people of an area safe. In addition to this there are various ways in which a building can be engineered so that it is resistant to the effects of disasters. Resonance frequency of building refers to the amount of vibration a building naturally has. If an earthquake is able to equal the resonance frequency of a building the building will collapse. Therefore, creating supports made from rubber or teflon that absorbs the shock makes it harder for the earthquake to reach the resonance frequency of a building. In addition, the taller the building the lower the resonance frequency of a building is and therefore they fall easier, hence more attention is paid to taller building. In new high rise buildings engineering has allowed the building to be flexible and move at the time of the earthquake helping to dissipate the shock of the earthquake. As well thick-oil can be used to move in the opposite direction of shaking to combat the movement as well.

Liquefaction:

Defending against liquefaction is also important. Areas that contain water saturated soils when shaken causes the ground to give way and buildings sink into the now liquid mud type soil. To defend against this, it is advisable to not build in the areas that are known to be saturated, weak soils. Adding more soil to the top of the existing soil can also be done. Liquefaction can cause huge damage to buildings and property.

Regulation and Tsunami Resistance

The protection of buildings and infrastructure from tsunamis is hard to manage as they are such a powerful force of nature. Tsunami walls are seen as the primary option for stopping the wave. These walls made of solid concrete can be over 10 metres with the latest wall being constructed in Japan reaching a height of 12.5 metres to prevent tsunamis from rushing through the cities and towns. Tsunami resistant buildings can also be created and though the building will still be damaged the damage is minimised. The idea behind the technique is that the walls of the ground floor around able to be destroyed and hence water can pass through the building, though the structural frame can withstand the tsunami and hence support any other floor above. Though there are limitations as water levels from the Tsunami in Japan were as tall as ten metres and so combatting against the disaster is hard.

How can lives be saved:

The forces created by natural disasters especially tsunami are hard to combat against. Infrastructure can be put in place to minimise the damage of both earthquakes and tsunami and sea walls can be erected to try and prevent the damaging waves from moving through towns. These are good ways of minimising damage to towns though these events will still happen and sometimes defence like sea walls will be breached just like in 2011 in Ofunato Japan and so it can be seen that the most relevant way to minimise death and injury is through education and warning. As stated earlier only 58% of people moved to safety when alerts were sent out in Japan during the 2011 Earthquake and Tsunami. Hence education needs to be wide spread about the dangers of the disaster and what to do in the case of an emergency. As well as this, warning systems need to be continually developed and new avenues such as electromagnetic anomalies need to continue to be explored as the best way to save lives is through early warning and education.

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