Additionally, many human and physical factors can contribute to the effects the volcanic eruption has on an area. Planning and preparing for volcanic eruptions effectively can reduce the impacts they have on an area significantly. The Education of local people about volcanic eruptions can reduce the effects of a volcano substantially. If one is educated about different aspects about preparing and planning for eruptions they are more likely to evacuate the area quicker.
For example, In Montserrat the farmers were not educated about the effects that the volcano would have, and therefore ignored the numerous warning signs, as they did not have the education that perhaps, a more developed country may have. The eruption of Mount Etna eruption in 1991 shows how effective preparation and planning can have positive effects on a volcano’s hazards. Mount Etna is Europe’s highest and most active volcano, whilst being viewed as one of the worlds best managed.
Prior the 1991 eruption of Mount Etna, massive barriers had been set up on the slopes of the volcano. This was not a permanent solution but to delay the start so that of the eruptions other methods could be brought in. Helicopters dropped concrete blocks through the tops of the volcano on the to block some vents in order to redirect the lava flow. Mount Etna is now lined with many sensors to detect any sign of an eruption with a combination of magnetic, seismic and video sensors linked to a monitoring station, sending a text at any warning that an eruption may occur.
This is warning system is necessary as Mount Etna is on rich fertile ground, where 25% of Sicily’s population live. Due to the volcano type that mount Etna is (composite strata), when eruptions happen, the lava is easily managed, even though it is able to travel large distances. Lava bombs and pyroclastic flows are not a great threat when the volcano erupts. All in all, the techniques of planning and preparation prior to the eruption of Mount Etna in 1991 mitigated the effects of the volcanic hazards by a large amount as shown by the little damage the eruption did to the surrounding area.
However, the effects of the eruption in Montserrat were devastating in comparison to Mount Etna, due to the lack of preparation the eruption had. The first eruption in Montserrat in 1995 was completely unplanned and prepared for. The volcano had been dormant for more than 300 years and so the eruption came as a complete surprise. The Montserrat Volcano Observatory was recognized shortly after the first eruption of the Soufriere Hills Volcano on July 18th 1995. The stations are located around the volcano and detect the ground movements caused by local earthquakes and dome collapses.
Occasionally, large earthquakes outside Montserrat are also recorded. The seismic signals are monitored 24 hours a day at the Observatory. The second eruption on 25 June 1997 affected Montserrat in a number of ways, even though the volcano observatory had been put in place. This could be due to Montserrat being an LEDC, and therefore it cannot afford to implement expensive eruption detection technology. Exclusion zones, however, were put in place to ensure that minimal amount of damage would be done, following the eruption.
The eruption had many impacts on the environment; the main component of the eruption causing the most devastating effects was the pyroclastic flow (hot ash, rocks and gas), which alone killed around 19 local people. Following the eruption, a total of at least 4 square kilometers of land was covered by the deposits from the pyroclastic flows and surges The fine grained pyroclastic surges broke and flattened trees. In some areas there was no vegetation left at all, vegetable beds were bare of plants and the soil was extremely hard. The lack of planning and preparedness the eruption had shocking effects on the local people as well.
The volcanic eruption destroyed between 100 -150 houses. The houses were buried by debris from the pyroclastic flow, burned by the hot pyroclastic surges, or set alight by the intense heat in the atmosphere. Most of the houses destroyed were in the Exclusion Zone and should have been empty but an estimated 15 people were living and sleeping in the Exclusion Zone. It can be argued however, that the main cause of the effects of the eruption were unavoidable, the pyroclastic flow, as one can never be prepared for the size of the eruption a volcano might have.
It is clear that, from the two case studies, that planning and preparedness can mitigate the effects of volcanic hazards to some extent, shown by the way in which the eruptions Sicily and in Montserrat were planned for and the effects of both volcanic eruptions. However, there are many other factors that can influence the effects of an eruption, such as volcano type, length of eruption, and other influences of which no country can prepare totally for.