The Physical and Human Factors Which Affect the Location and the Impact of the Earthquake Hazard

The Physical and Human Factors Which Affect the Location and the Impact of the Earthquake Hazard
Earthquakes are natural hazards that have occurred since the dawn of time. They are products of the Earth?s ever-changing face and lead to the movement of the world?s tectonic plates. An earthquake is a hazard resulting from major geological processes and the release of energy within the earth leading to catastrophic incidents such as earthquake and volcanic eruptions. The effects of earthquakes can have considerable damage to the physical and human environments and the impact and location of an earthquake can alter the damage of the process. Earthquakes are most likely to occur at the boundaries of the lithospheric plates. They occur from movements along fractures in rocks called faults. Movements occur along the faults because of the stress put upon the area due to crystal movement, the stress is not released gradually but it builds up and becomes so great until the rocks are forced to shift suddenly along the fault. Once the fault moves the shock waves produced results into an earthquake, the point of break is called the focus. The physical factors that effect the location and impact of the earthquake can have a large impact upon the hazards the process causes.
The location of the earthquake is most likely to occur at plate margins thus if a settlement is located alongside these plate margins it is more likely that they are going to receive earthquakes than settlements not located upon the plate margins. The city of San Francisco located above the San Andreas Fault is one of the most earthquake prone cities in the world and receives small earthquakes everyday. The location of the focus is also very decisive when considering the impact that the earthquake might yield, if the focus is located far below ground then the shock waves will be absorbed by the ground and the impact that the earthquake will have will be minimal. But if the focus is located several meters below ground such as during the Loma Prieta earthquake in 1989 then the impact will be devastating. If the focus is located out at sea like it was during the Mexico City earthquake in 1985 then the shock waves will enchanted by the water thus increasing the strength of the hazard and also it will create tsunamis which means that the amount of damage that the hazards brings will be increased. Another physical factor that can effect the impact of the earthquake is the foundation material that the area above the focus is developed upon. If the foundation rock is granite then the shock waves will become absorbed more reducing the damage that the earthquake brings, but if the rock type is weaker such as limestone then the shock waves will not reduce in strength and the impact of the earthquake will increase in destruction. Another physical factor which can effect the impact of an earthquake is the duration of the shaking, the longer the shaking the more damage the earthquake will cause. This will mean that the impact of the hazard will increase in damage if it occurs for long stretch rather than occurring in small shakes. The human factors differ greatly from the physical factors but exert the same or more amount of damage. There are not a lot of human factors that can effect the location of an earthquake but a known example that has caused an earthquake to occur is because of the construction of a reservoir and dam. This occurred in the middle of the Indian subcontinent well away from the Himalayan collision belt at Killari. The construction of a dam and reservoir meant that the weight of the water in the reservoir and the increase of pressure in the rocks lubricated the fault line so that it could move easier and thus triggering off an earthquake. There are a lot of human factors that can effect the impact of an earthquake, such as the quality of buildings, population density and level of warning system. The quality of buildings is very important very considering the impact that an earthquake can have upon a city, if buildings have strong foundations are earthquake resistant then the impact that a earthquake will bring about will be minimal as damage will be restricted as buildings are earthquake resistant. Population density determines the amount of people living within a given area, if the population density within an earthquake-hit region is high then the amount of human deaths and injuries would be high and thus the impact that the earthquake would be great. How well a warning system can save many human lives and thus restrict the impact of an earthquake, thus in MEDC?s as they are more economically stable are able to spend upon high-tech warning systems and thus people will be saved from the damage of the earthquake. But in LEDC?s the government is not as rich and thus cannot spend money on warning systems thus the impact of an earthquake would increase. How developed a nation is will determine how much will be spent upon decreasing the impact of an earthquake, although MEDC?s cannot stop earthquakes from occurring they can restrict the amount of damage that occurs. LEDC?s are not able to spend highly upon earthquake resistant infrastructure and thus the impact of the earthquake would be greater at LEDC?s than MEDC?s. Thus in conclusion it can be said that the location of an earthquake is most likely to be determined by physical factors. But the impact that an earthquake can be determined by both human and physical factors, thus the impact of an earthquake cannot be solely related to either human or physical factors.

The Physical and Human Factors Which Affect the Location and the Impact of the Earthquake Hazard 8.2 of 10 on the basis of 1261 Review.