With Reference To At Least Two Case Studies, One Each From An MEDC and An LEDC, Explain Why LEDC's are More Vulnerable Than MEDC's to Earthquake Hazards.
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With Reference To At Least Two Case Studies, One Each From An MEDC and An LEDC, Explain Why LEDC's are More Vulnerable Than MEDC's to Earthquake Hazards. An Earthquake is defined as 'A series of vibrations and shock waves which are initiated by volcanic eruptions or movements along the boundaries of oceanic and continental plates.'1 The point of origin is called the focus, with the epicentre being the place on the surface directly above the focus. There are three types of shock waves: Primary; Secondary; and Surface. The energy released by an earthquake, the magnitude, is measured on the ten point Richter Scale. The severity of Ground Movement, the intensity of the earthquake, is measured on the twelve point Mercalli Scale. Figure 1 shows a comparison between the Richter Scale and the Mercalli Scale. Figure 12 Modified Mercalli Scale Richter Scale Earthquakes Per Year <III IV-V VI-VII VIII-IX X-XI >XI <3.9 4-4.9 5-5.9 6-6.9 7-7.9 >8 830,000 62,000 500 100 20 >0.5 The reasons why an LEDC might be more vulnerable to an earthquake are fairly numerous. These factors, that make it more vulnerable to earthquake hazards, could be seen as what classify it as an LEDC.
Economic realities usually determine the goal, not of preventing all damage in all earthquakes, but of minimizing damage in moderate, more common earthquakes and ensuring no major collapse at the strongest intensities. An essential part of what goes into engineering decisions on design and into the development and revision of earthquake-resistant design codes is therefore seismological, involving measurement of strong seismic waves, field studies of intensity and damage, and the probability of earthquake occurrence. The training and experience that emergency services have is also a major factor to assessing how vulnerable LEDC's are to earthquake hazards. This needs careful organisation and planning, with a clear specification of the role of each group of people. Responsibility for decision-making needs to be identified. One of the key issues for emergency services is where to deploy their people and equipment in an area, which may have suffered disruption of transport and communication lines. New computer developments are helping to make emergency response more effective. The Tokyo Gas Company has a seismic network, which transmits information to a computer using a radio network. This informs the company about pipeline damage so that gas can be switched off and fires and explosions reduced.
The factors listed above all help to explain why LEDC's are more vulnerable to earthquake hazards, although they also affect MEDC's. This was true for the 1995 Kobe earthquake, which killed 5,500 people. All the modern earthquake prediction techniques and machines did not help to predict this earthquake. The earthquake caused buildings to collapse, railways and roads to split and fires to break out. All the modern techniques for protecting an MEDC, and reducing the hazards, only helped to reduce the impact, which was still enormous. Japan is positioned on the margin of the Eurasian Plate. The Philippine Sea Plate is subducted below the Eurasian plate, resulting in Japan having greater than average seismic and volcanic activity. Immediately south of Osaka Bay is a fault called the Median Tectonic Line, and it was sudden movement along this fault that triggered the earthquake that hit Kobe. The cost of the 1995 earthquake was estimated at being about $200 million. It could be true to say that loss of life is greater in LEDC's but the loss of capital is much greater in an MEDC. 1 The Complete A-Z Geography Handbook - Malcolm Skinner, David Redfern & Geoff Farmer. 2 Advanced Geography - Nagle 3 Adapted From Hazards and Responses - Victoria Bishop 4 Adapted From Hazards and Responses - Victoria Bishop 5 Map provided from http://www.allworldmap.org/pic/armenia.gif O.Armitstead Page 1
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