‘Volcanoes are easier to monitor and predict than earthquakes.’ With the use of
examples to support your opinion, evaluate to what extent this statement is true. [20]
Over the centuries, people have suffered the consequences of natural disasters such as
volcanic eruptions and earthquakes. As a result, they have developed technology and
different measures to try and observe and forecast such tectonic activity. This essay will
evaluate, using several examples of different eruptions and earthquakes, whether volcanoes
are easier to watch and anticipate than earthquakes, and to what extent.
It is commonly believed that volcanoes are easier to predict than earthquakes, and there are
several reasons for this, the main reason being that there are more signs and observations
which can indicate an upcoming eruption. Not only are there pre-eruption earthquakes, there
are also increased sulfur levels, physical swelling of the volcano and physical observations
such as smoke. In June 1991, long before the advanced technology of today, volcanologists
were able to predict the eruption of Mt Pinatubo in the Philippines, as there were several
indicators of an upcoming eruption: emitted sulfur dioxide levels had increased from 500
tonnes per day to 5000 tonnes per day; seismic stations surrounding the volcano showed
that there were earthquakes occurring up to 8km under the surface and spread over a large
area; aerial observations showed that the volcano was shaped like a dome. This final
indicator convinced volcanologists to sound the alarm - thousands of people were evacuated
and it restricted the death toll to below 500. The eruption on June 15 was of VEI 6 and the
second largest of the 20th century and it shows that it is indeed easier to predict volcanoes
as there is more data and more physical evidence to base the predictions on.
However, it has not always been the case that volcanic eruptions have been predicted
successfully, more often than not, they have actually not been predicted. This is because,
although volcanoes give certain signs that an eruption may be looming, it is impossible to
know for certain whether a dangerous eruption will occur. This has been evident in the 2014
Mt Ontake eruption in Japan, where failure to predict the eruption caused the death of 60
people, most of them hikers. Although there were signs that could indicate a coming eruption
- on September 10 and 11 the frequency of earthquakes under the volcano increased slightly
before decreasing again on the 12th - these were minimal and not significant enough to
mean anything. The only other signs were the volcanic tremors that occurred 11 minutes
before the eruption followed by rapid inflation of the volcano 4 minutes later, these were not
enough to warn people on time. Therefore, it can be concluded that volcanoes are just as
difficult to predict as earthquakes, which can also be very sudden and without many signs.
Similarly to the Mt Ontake eruption, earthquakes are also extremely difficult to predict. This
is due to several factors. Firstly, not only is the date, time and magnitude of the earthquake
needed, the location of it is also needed. Secondly, although there may be signs such as
changes in seismic activity, uplift and radon gas concentration, these are not enough to be
able to confidently predict earthquakes, and there are no physical observations which have
been crucial in predicting volcanic eruptions. An example of this is the 2009 L’Aquila
earthquake, of magnitude 6.3, which killed 309 people. The people were completely
unprepared for it, and although there had been some micro-earthquake activity beforehand,
this was not enough for the scientists to confidently predict the earthquake. This is just one
of the many examples where it has been close to impossible to predict earthquakes, which
just goes to show that volcanic eruptions are indeed easier to predict.
