To what extent is magnitude the main factor to influence the type and level of challenge posed by tectonic hazards?

by matt1113 (student)

Introduction

Garret Nagle in 1998 defined a tectonic hazard as “A perceived natural event in the environment which poses a threat to human life and property”. Also adding to this we have a definition of a Natural hazard as “an event or process that has the potential to cause damage to people and their settlements” (Ross, 1998). These two definitions infer that in order for a tectonic process to become a hazard it should happen in proximity of human beings or have a direct impact on them. Following on from this Em-Dat states that in order for a hazard to turn into a disaster it has to meet at least one of these criteria: 10+ people killed, 100+ affected, State of emergency declared or International assistance called for. The aim of this report will be to analyse the effects that Magnitude has on a tectonic event and if it is the most influential in determining the impact of the event. I will do this by analysing relevant case studies where magnitude seemed to play influential role and weather it was the main factor in the disaster. The two case studies that seem to stand out are Japan 2011 and Haiti 2010 as both where hit with different magnitude earthquakes but the impact it had varied considerably. In determining if magnitude is really the main factor I will examine a range of factors that play a role in these events and thereby, examine the legitimacy of this statement. The other factors I will evaluate are Level of development where I will consider if the country’s economic standings have an affect on there vulnerability to the hazard and to do this I will use examples from Haiti in 2010 and Chile in 2010. Another factor that could be as influential as magnitude or maybe even more could be Duration, where how long the event lasts for could have a significant impact on its damage to the physical and natural environment and to explore this I will use examples from the Iceland volcano 2010. A further, factor which plays its part in the outcome of tectonic events is Frequency. In this I will examine how influential it is for an earthquake to constantly occur or to never occur in a certain area and what impacts that may have. In order to do this I will go through the case studies from Chile 2010. The final factor I will go through is Geographical Characteristics where I will examine how the outlay of the land has an impact on the size of the event and to properly asses this I will use the case study of the earthquake in Haiti 2010. I will do this to properly evaluate if magnitude is really the main factor that influences the challenge posed by tectonic events or if it’s helped on by other factors.

Methodology

The evidence used in these case studies has been taken from a wide array of reliable sources including books, academic journals and the internet. These sources all help provide up to date knowledge and information. However, I am aware of the inconsistencies in some of these sources such as the internet. Consequently, in order to counter this I have cross referenced any information I have gained online in order to ensure it is accurate and reliable. This is done to avoid any inconsistent references or inaccuracies which could undermine the validity of the report and its conclusions and to ensure the information is both reliable and reliable.

Analysis

This is a preview of the whole essay

Analysis

The first factor that I will go over is magnitude as the statement claims it is the most influential. This statement has its true points; if the magnitude of the event was severely large on the Richter scale then the level of challenge it will pose will be far greater. This could be seen in the Japanese earthquake in March 2011. Although Japan seemed to have a high level of preparedness to such a hazard, with defences such as earthquake proof buildings where buildings would sway with the earthquake in order to prevent collapsing and concrete barriers to prevent flooding as well community preparedness where people knew what to do in such an event. To further their defence warning systems where in place to help prevent a disaster from a hazard (BBC, 2011). However, due to such a huge tectonic process, earthquake detection systems where only able to warn people as early as 80 seconds before the impact. As the earthquake also occurred out in sea it set off a trigger of events that caused in a Tsunami to wreck even more damage. From this one 9.0 magnitude earthquake Japanese police confirmed a death toll of around 15,700 and around 6000 injured (BBC, 2011) with further thousands missing. As well as 125,000 buildings destroyed from both earthquake and tsunami (Guardian, 2011). The earthquake also caused damage to one of Japans main nuclear power plants which lead to the evacuation of millions from the area. Although Japan seemed relatively prepared for this sort of event the sheer scale of such a event was not predicted, this rendered most of Japans defences useless, as people where only given 80 seconds to retreat to safety (smartplanet.com,2011). As well as this the events that followed also added to the destruction where if people survived the earthquake they were left venerable to the tsunami. All this was set off from one high level tectonic process. However, if the magnitude of the earthquake is a significantly lower one then the level of challenge is also lower. For example, the 5.3 magnitude earthquake that occurred in Lebanon, Israel 2008 that occurred 60km underground. Although Israel is not as prone to earthquakes as Japan which could result in them having a higher vulnerability, as people do not perceive there to be a risk and less is invested into managing such a hazard. However, as the magnitude of the earthquake was such a low one there was almost next to no impact on the human population and the physical environment. As the only reported results of the earthquake were a few houses shaking for a few seconds and minor damage to a main road (ytnews.com, 2008). Also as the earthquake was so far the underground the magnitude of the initial shake would not be felt on the surface as it had to travel so far which reduces the magnitude significantly. Consequently, as the tremors of the earthquake where so weak in force any potential hazard that was there didn’t occur simply as there was no energy behind the tremors to cause harm to anyone or anything. This helps support the statement as changing the magnitude of the earthquake has a major effect on the level of challenge is poses.

Another factor worth examination is the level of development. This is where a countries economic standing has the potential to impact on level of vulnerability of an area and the potential of turning a hazard into a disaster. It could be the case where a country is so poor that it simply cannot afford to maintain or start up hazard management or defence schemes as it would mean taking funds away from things that are perceived as important by the public such as: Healthcare. A perfect example of this could be seen in Haiti, January 2010. Where a 6.9 magnitude earthquake struck the capital city of Port-au-Prince. Haiti is seen as one of the poorest countries on the western side of the hemisphere, with 80% of the country’s population living below the poverty line. It has no natural resources and is largely dependent on agricultural farming. Also there is a major lack of emergency services with there being no military or air force. Due, to such severe conditions people are forced to build their homes on marginal land and on top of other people’s homes creating large shanty towns (BBC, 2010). They are also not able to keep to any building regulations due to a lack of resources and funding their homes are extremely venerable to any hazard. But, people are almost forced to live in such conditions as they have no other option. When the earthquake struck and although it’s a relatively lower magnitude than the one in Japan, its impacts are hardly comparable. With a death toll of over 316,000 and a further 300,000 injured due to collapsing buildings such as the hospital which left any aid available almost obsolete (Em-Dat, 2010). Adding to this as there were no internal emergency services Haiti had to call for International aid, which took a day to arrive. If emergency services arrived earlier many lives could have been saved. As well as this due to the complete destruction of the city search and rescue teams had to move very slowly searching every area of rubble. This also left nearly all of Haiti’s commercial buildings out of use further damaging the economy to a state where it still hasn’t recovered (BBC, 2011). However, if a country has a relatively high level of development then they are in a better position to have community preparedness projects, earthquake proof designed buildings and emergency services. This could be seen in February 2010 in Chile when an 8.8 magnitude earthquake struck. Although the magnitude of the earthquake was an extremely high one compared to Haiti the impact it struck was a significantly lower one. The earthquake left a death toll of 525 and 370,000 homes destroyed (Independent, 2010). This significantly lower impact was largely due to the residents of Chile perceiving there to be a hazard as Chile is prone to earthquakes. This meant that the Chilean government taking this into account and investing in earthquake preparedness schemes which resulted in many of the people trapped in homes being rescued by their neighbours as they knew what to do and where to go in such a event which is what the Haitian’s lacked. These examples are perfect for showing why Magnitude might not be the most influential factor in a tectonic event as Haiti had a lower magnitude then Japan or Chile but the impact they received was much greater and Chile received a high magnitude earthquake but the impact was relatively low in accordance. This contradicts the main statement, perhaps when Magnitude and Level of Development are mixed it is the most influential factor as magnitude is needed to have any impact.

Another factor that could have influential impact on a tectonic event is Duration. Where the amount of time an event lasts for could cause it to have a higher impact also means it is harder to respond to and manage. An example of this could be seen when a volcano in Iceland erupted in April 2010. The following eruption, interacted with the weather conditions at the time pushed a huge cloud of ash east over Britain and Europe which delayed flights in and out of Europe for as long as 11 days forcing 20 countries to close their airspace. Due to the severe length the ash cloud lasted companies lost billions in revenue due to cancelled flights, also as there was no way to respond to a crisis until It is over. Meaning countries and tourists could do nothing but wait. This shows that Magnitude is not always the main factor as it has barely any effect on this hazard and it’s sometimes its due to various other factors. So, in some cases the main factor varies and is not always magnitude.

A further factor that has an influence on the level of challenge posed by tectonic hazards is the Frequency in which the hazard occurs. By this it is meant that If the hazard occurs more often in a certain area, then the inhabitants are more likely to perceive there to be a threat and counter that by setting up management schemes and having earthquake prone structures. An example, of this could be seen in Chile 2010, where the land is prone to earthquakes that the population are taught ways to lessen there vulnerability to the hazard and to reduce any impacts by evacuating at first instance of the hazard. This was seen by a very percentage of the population that was effected by the disaster which where recued by their neighbours and the number of lives that where saved from people knowing how to react to the hazard. This shows us that magnitude might not be the most influential factor as if a country is used to such a event then they will take measures to lessen the impacts that it will have to prevent a hazard becoming a disaster. Whereas if the country is not prone to earthquakes such as Haiti where people perceived there not to be a threat then the death toll is considerably higher. References? Linking back to title?

The final factor I will examine is Geographical Characteristics, where the outlay of the land and its surrounding infrastructure has an influential role in determining the impact of a geographical event. Where, the landscape is hilly or muddy and as a result of the earthquake becomes hard to navigate through. An example of this could be seen in Haiti 2010 were due to the countries low economic status and a significant percentage of its population living below the poverty line they were forced to build their homes on marginal land and not follow any building regulations, due to a lack of resources(BBC, 2010). Also as the homes are all packed together it created a harder job for any emergency services to reach people trapped in mountainous areas (Guardian, 2010). Due to the high levels of debris of mud. The geographical characteristics could also have an effect on the impact of the earthquake as if the land is flat it won’t be as hard hitting as if it was mountainous. This shows us again that it magnitude might not be the most influential factor in determining the challenge posed by tectonic hazard and it may be a mixture of factors.

Conclusion

To conclude, I believe the overall statement that magnitude is the most influential factor in influencing the level of challenge posed by tectonic events is true in some aspects. As it is needed for any tectonic event to actually become a hazard as in order for it poses any threat to human life it must have the energy to do so. This can be clearly seen in the case study of Japan 2011, where even though the country seemed appropriately prepared for such a hazard the sheer size of the event bypassed any defences. Whereas, if it was a lower scale event it would not have caused so much damage. However, I don’t believe that magnitude in itself is the most influential factor. Although, it is needed in the process I believe that in each individual case a mix of factors is used to determine the level of challenge. For example, in Haiti where the magnitude was not really an important factor in the outcome and most influential factor was actually Level of development. To sum up, I believe that Magnitude is an influential factor but no factor by itself is the most influential and that a mixture of factors add up to determine the level of challenge posed by a tectonic event.

Are you suggesting that the combination of factors might actually vary depending on where the event takes place and the specific characteristics and combination of factors in each location? You could reach this conclusion and include it to really round your argument off.

This is a big improvement Mert. You have structured your essay more clearly and have more robust use of evidence and references. You do need to make sure this is consistent, and you should make sure you cover more than earthquakes; you don’t seem to make any mention of volcanoes in what you’re doing here. You need to make sure you have a range of case studies and hazards. You also need to make your conclusion more rigorous and explain more clearly why one, or a combination of factors are more important. You again only make mention of a small range of hazards types in your conclusion.

8 + 9 + 14 + 8 + 6

45/70 (C)