Volcanic Hazard Preparedness

To what extent can preparedness and planning mitigate the effects of volcanic hazards?
Volcanic activity happens across the surface of the globe and naturally hazards occur too. It can be said that it’s easier to predict an event than prevent it, however prediction does have a positive impact on the effects of a volcanic hazard. Firstly, the extent to which preparation and planning can decrease effects can only be done by prediction. There are numerous ways in which volcanoes can be monitored but it does mean expense. The technology needed and the expertise in which to predict a volcanic hazard can only be generated by a good economy. Therefore some of the poorer countries cannot afford planning and such things. The impact that is experienced
in LEDC’s is often more severe than that experienced by MEDC’s. This also presents the idea that the severity of an event can never be truly predicted. These poorer countries often experience violent eruptions due to the boundaries they are on. The 2008 eruption of Chaiten in Chile saw the volcano erupt for the first time in 9’400 years. Chile is an LEDC and this meant not a lot of monitoring was done. It was not classed as a high priority due to the long dormancy and low local population density. However the amount of ash had a big impact on the country with flights being cancelled and many thunderstorms as a result of the eruption led to two countries airports being shut. This all does give evidence that if it had more preparation, plans could have been made to mitigate the effects on the country. There are many ways used to study and monitor volcanic activity, including sampling gas and lava emissions, studying geology and studying seismic patterns. However studying patterns and other such things cannot give a definite answer, just an estimation. An example being Yellowstone National Park. It is said to be a super volcano which is due to erupt any time now. Although it erupts around every 68’000 years it cannot be exactly known when it will next erupt. Due to this even though some planning has been done not enough knowledge means we don’t know how extreme it will erupt. Following on from this, volcanic eruptions come in different forms means the severity varies as said previously.
Volcanoes on a destructive plate margin often lie dormant for years but have explosive and violent eruptions with acidic lava, pyroclastic flows and copious amounts of ash. Because of the length of time that they lie dormant prediction isn’t as easy. Montserrat in the Caribbean experienced a violent eruption in the mid 1990’s. The early activity showed signs of a major eruption so many people were able to be evacuated , giving evidence that preparedness and help decreased the effects of the eruption. Exclusion zones were set up leading 7’000 of the 11’000 inhabitants to be resettled in other countries. This prevented a huge loss of life. The capital, Plymouth, was buried in the ash fall, so with the evacuation all of the inhabitants were moved, meaning the largest population density on the island was prevented from being lost. Not only does planning attend to before an event, it provides plans for during and after as well. Therefore the island of Montserrat has provided farming areas for those who resettled in the north, the movement of the capital city of Plymouth to Salem and financial help for those who were resettled. Without the preparation time this planning would not have gone ahead, resulting in a much worse state. The extent of the planning has helped shrink the effects for the people after the
eruption. Furthermore preparedness can also prevent effects. If an event is predicted and known to happen, certain things can be put into place. The eruptions in the 1990’s of Mt. Etna saw the development of protections measures. Firstly a large earth barrier was built which was several tens of metres high and more than 400m long. This held back the lava for several months. Due to the planning there were many strategies to prevent the lava from hitting large towns. As the lava began to spill over the earth barrier the smaller barriers were hit, but were overwhelmed with the amount of lava. Only a few smaller buildings and orchards were lost compared to the hige amounts that would have been lost without the protection methods. Other techniques including dropping concrete blocks to cut off the lava flow from the primary feeder channel and openings being blasted into the lava tube to encourage a new direction flow. This protected the town of Zafferana. The planning of these methods lowered the effects of the eruption drastically, thus proving it does mitigate the effects. To conclude even though it can never be definite as to when a volcano will erupt, the prediction can lead to preparation and planning. The example of Mt. Etna proves that this does really lead to less effects, and can prevent the loss of towns as well as the loss of iife.