Volcanic Activity: Hazards to People

Only available on StudyMode
  • Topic: Volcano, Volcanic Explosivity Index, Lahar
  • Pages : 5 (1696 words )
  • Download(s) : 1
  • Published : April 25, 2013
Open Document
Text Preview
Volcanic activity can present a hazard to people and property in various ways and with varying degrees of severity. Whether or not these represent a significant danger to people is dependant on how well prepared the area surrounding the volcano is. The level of preparation is often linked to the overall wealth of the country which the hazard is in. This also impacts how effectively the volcanic even is managed before and after the eruption takes place. The timing of an eruption throughout the day, week or year can greatly change the number of deaths which occur. It is also worth mentioning that the intensity of a volcanic eruption has a great impact on its potential to damage people and property.

It is commonly thought that . Iceland is situated on the Mid Atlantic Ridge in the Atlantic Ocean, the mountain chain created by the North American and Eurasian plates moving away from each other. As magma rises to fill the gap created by the plates moving apart, it solidifies creating a mountain chain. In some places the mountain chain rises above the level of the sea to form volcanic islands. In the case of Iceland, volcanic activity is something which occurs frequently. For example in January 1973, the island of Heimaey was the focus of a fissure opening and releasing vast quantities of lava and ash were erupted. As Iceland is a relatively rich country, it had the resources to evacuate the nearby port town of Vestmannaeyjar (population 5,300) in under 7 hours. Furthermore, the state had the resources to pump water onto the lava flows, solidifying up to 20,000m3 of lava every hour. This prevented much of the town from being completely destroyed. This shows that in rich countries, it is very much possible to evacuate an area and prevent all human deaths. In contrast, however, in 1783 the Laki fissure opened, releasing lava which covered 565km2 of land, which itself presented little risk, just 40 farmstead were damaged. However poisonous gases killed half of the cattle and a quarter of the population of Iceland at the time (9,000 out of 36,000). This shows that depending on the nature of the hazard, the effect on human life can be very different i.e. lava flows may not necessarily kill, but poisonous gases (such as carbon dioxide) couldn’t have been avoided at the time. This ties in nicely with the time element of the hazard. In 1783, no practical methods of detection poisonous gases existed, however with modern technology it would be possible to detect gas clouds and thus issue an evacuation warning, which would have prevented the deaths of most if not all of those killed by the toxic gas.

Generally, whether or not a country’s government has the facilities to predict and manage a volcanic eruption greatly affects the total death toll. However this is not always the case, as is shown in the eruption of Mt Pinatubo on the island of Luzon in the Philippines in June 1991. The Philippines is an LEDC, however the American run Clark Air Base had many geologists and vulcanologists stationed there. They were able to predict the eruption and recommend the staged evacuation of over 70,000 locals and 15,000 Americans in the air base. Had these specialists not been stationed in the region then it would have been likely that little warning would have been given and potentially everyone in the area killed, rather than the 800 or so who are believed to have been killed.

A country which does not have the influence of a MEDC is likely to suffer much greater casualties due to lack of warning and poor management after a volcanic eruption. A good example of an eruption which could have been managed much more effectively is the 1985 eruption of Nevada Del Ruiz. Here 25,000 people were killed and the entire town of Amero was submerged under 5m of mud due to lahars, however the majority of the death toll could easily have been avoided, the eruption itself was not particularly violent and the primary hazards of the eruption were not particularly...
tracking img