earthquakes. In the map below, it is evident that
these features of tectonic activity, occur along plate
boundaries as these are the causation for seismic
activity. A particularly area of distribution is the Ring
of Fire because it exemplifies the connection
between the risks associated with high density
areas of population and seismic activity combined.
In laying home to over 800 million people, 90% of world earthquake activity and 50% of the world's active
volcanoes; the links between the two variables needed to calculate risk are impossible to ignore.
From the detailed comparison of the maps above, the West coasts of South America and North America and the
Ring of Fire region have both density of volcanoes and people; strong positive correlation between the two
variables implicit of how both are necessary in hazard prediction. However, the volcanoes will always stay in situe
so the dynamic changes of population density do appear more dominant in terms of volcanic hazards. In using the
population trends stated previously there are a great many factors drawing people into areas of seismic activity so
population distribution is only going to increase in density within seismic prone areas, so human dispersion is vital
in recognising both future and current hazards. All preceding knowledge is summed up in Kofi Annan's
assessment:"At no time in human history have so many people lived in cities clustered around seismically
active areas...Poor land-use planning; environmental mismanagement; and a lack of regulatory
mechanisms both increase the risk and exacerbate the effects of disasters," which clearly illustrates the
relationship between volcanic disasters, populations, planning and development; demonstrating the vital
influence of population change in risk reduction. Furthermore, humans being the victims of the greatest hazard is
emphatic given half a billion people live in 'spitting distance' of active volcanoes. Therefore, all such theory leads
me to exemplify the two arguments stated previously:
In light of the first argument, the main hazard to any natural disaster is humans, so in densely populated areas their
location must be taken into account. In the case of the Mount Nyiragongo eruption (Congo), its proximity to the
dense population of the city of Goma, 16km south-west of the volcano, increased hazards. With a population of
500,000 people, 147 were killed because the 40mph lava flows reached the densely populated area quickly. 1/3 of
Goma was destroyed along with 14 villages along the path to Goma, from the Volcano and through the valley.
Therefore, such an eruption would have benefited from focus on the population dispersion analysis rather than just
when the volcano would erupt because evacuations needed to have been put in place. The pseudo-mathematical
equation for risk 'Risk = Hazard x Value x Vulnerability / Capacity' (Value indicating the elements at risk (number of
human lives, economic value of property, etc., while vulnerability refers to factors which increase the susceptibility to
the impact of hazards) highlights how the number of human lives and property at risk and the susceptibility of
these individuals is a bigger factor than the simplicity of seismic activity distribution because the environment can
recoup and the volcano is the effector not the effected. More importantly, the density of 'Value' and 'Vulnerability'
was the factor which most increased and determined hazards.
Contrastingly, the 1980 eruption of Mount St Helen's did not lead to massive casualties because, whilst there were
some deaths as a result of the eruption, there were relatively few because of its location in Washington State, with
no nearby cities. The 5 mile exclusion zone put in place limited casualties, as the 57 fatalities were mainly outside
of it because their fatalities were caused by respiratory illnesses brought on by the post-eruption prevailing wind.
Therefore, in conjunction with the fact that Mt St Helens had a more environmental impact in lowering global
temperatures by around 2 degrees on average in 1980 and grounding international air traffic, the argument for
sparse populations not needing population distribution as a dominant strategy in prediction hazards can be
proved. This is because the hazards were mainly environmental rather than deaths as in sparse population there are
other major effects because there is a lack of dense population at risk nowhere near as extensive as those in densely
populated areas. With reference to Volcanoes by P. Francis et al, "a hazardous volcano is not just one that is capable
of, say, a plinian eruption, but one whose ashes might collapse the roofs of buildings, deliver toxic levels of fluorine
to farmland pasture, or be drawn into someone's lungs or an aircraft's jet engines with potentially damaging results.
Hazard implies a phenomenon and something or someone it threatens" we can decipher that the hazards
experience at both eruptions are equally significant by definition, but in Mt. St Helens experiencing a phenomenon
Georgia Amos
and threatening the something, Earth and aviation, population distribution was not more important than the
prediction of the exact volcanic activity. For Mount Nyiragongo, population distribution was more important as the
pseudo-mathematical risk equation and the someone being threatened, a dense population, posed the greatest
hazard.
A further example of correlation between dense population and high death tolls is the Armero Tragedy, whereby
Nevado Del Ruiz erupted in 1985, leaving the town of Armero decimated by the Lahars flowing out of the volcano.
20, 000 of the 29, 000 inhabitants of Armero died as a consequence of the eruption, as well as 400 homes being
destroyed in the nearby settlement of Chinchina. Once again in contrast, the 2010 eruption of Eyjafjallajokull did
not lead to any deaths due to the relatively sparse population near the volcano. Instead there were a variety of other
major consequences across the world as a result of the eruption. Air traffic was grounded across the vast majority of
Europe as a consequence of the ash cloud making planes unsafe to fly. The event created economic hazard in that
the worldwide airline industry was losing 148 million euros a day during the eruption. Both, emphasise each of
their arguments and reflect the diverse tendencies of volcanoes which mean population distribution is a single
factor in the entire hazard prediction and reduction process.
Conclusively, hazards associated with volcanic activity are dependent on a variety of factors. The prediction of a
hazard associated with volcanic activity is far better than that associated with earthquakes because earthquake
tremors are the warning for volcanic eruptions so in monitoring and interpreting seismographs such diverse
destructive tendencies can be predicted reasonably well and exclusion/evacuation zones applied for human hazard
reduction. The difference lies in how some areas, i.e. those which are densely populated, have found that
population is vital in determining the severity of hazards at a time of volcanic activity, whereas there are other areas
where there has been a small population i.e. sparsely distributed populations, but a massive international effect
has occurred as a result of the eruption, leaving population distribution with no predictive capacity in such cases.
Therefore, no one factor can be stated as the single most important item in determining whether or not and to what
extent a volcano should be perceived as a hazard because each volcanic event is unique. For the future the
statement, "Europe, Latin America and the Caribbean, Northern America and Oceania are highly urbanised, with
proportions urban ranging from 70 to 82 per cent in 2010. Africa and Asia remain mostly rural, with only 40 and 42
per cent of their population living in urban settlements, respectively. By mid-century, however, all regions will be
mostly urban, indeed more than 60 percent urban, according to current projections" (United Nations Department of
Economic and Social Affairs Population Division) is suggestive that population distribution is only going to become
more present as a factor, but will never be the sole variable.
Georgia Amos
by
georgiaamos (student)
