In a way, it is possible to anticipate an eruption. Volcanologists can do this if they know the eruptive history of the volcano and have installed the appropriate instruments to monitor the data coming from within it. A set of seismographs, placed in strategic places, allows a detailed monitoring of all the seismic movements that accompany the rise of the magma from the interior of the Earth’s mantle, which are transmitted by radio continuously and 24 hours a day.
The small swings of the mountain as a whole are also measured, which we could call the respiration of the volcano, since they are an indication of how the magma moves through it. Another indication that points to a future eruption are changes in the concentrations of gases, such as carbon dioxide and sulfur dioxide. When the magma is in the mantle, these gases are dissolved in it , but as the magma rises and the pressure decreases, the gaseous compounds are released, and there the sensors allow detecting the slightest change.
However, knowing the past eruption patterns of a volcano does not ensure that it can be predicted when it will do so in the future, since they do not have to be repeated. In reality, the predictions of volcanologists are similar to those of meteorologists: they offer a probability that it will happen, but they can never be 100% sure. Even in the ideal case they are unable to decide exactly what the intensity of the eruption will be.
But that doesn’t make their work unworthy of recognition: volcanologists were able to predict the June 1991 eruption of the Pinatubo, saving tens of thousands of lives. In this case, what put the experts on alert was the sudden rise in the amount of sulfur dioxide to unprecedented levels: 16,500 tons a day.
