If we take into account the frequency of their eruptions, volcanoes can be divided into three types: active, inactive –also known as dormant– and extinct. The former can generate dangers of a very diverse nature: emission of lava, solid fragments thrown into the air – ballistic projection pyroclasts -, ashfall, volcanic gases, etc. The probability that one or more of them affect an area in a specific time interval is what determines their degree of threat.
Inés Galindo, head of the Las Palmas de Gran Canaria Unit of the Geological and Mining Institute of Spain (IGME), explains that, to carry out a hazard analysis, geologists walk through the volcano with “notebook, compass, hammer to take samples, GPS, map and mobile or tablet. The review of historical documents on past eruptions, field work and study of the samples help to reconstruct the eruptive history of the volcano. With all this, a map is made using statistical methods and mathematical models that indicate where an eruption is most likely in the future, the type and characteristics of the most probable volcanic hazards, as well as their frequency ”.
And the fact is that the data is key. The main advances in this field have been in statistical methods and simulation models, which include artificial intelligence. This, for example, could help to understand volcanic eruptions from the different forms of ash.
Now, as the IGME expert warns, “the main problem is that sometimes models are given more importance than input data. The results will be more reliable the higher the quality and quantity of information captured ”.
The awakening of the Bolshaya Udina
Among the countries with the most active volcanoes in their territory are Chile –where there are about 95–, Indonesia –with more than 120–, the United States –has around 130–, Japan –with around 66– and Russia. It is precisely in the latter territory that the Bolshaya Udina is found, a volcano located 2,920 meters above sea level, on the Kamchatka peninsula, which was believed to be extinct and which, however, according to data from a new study, returns be active.
This research, published by the Journal of Volcanology and Geothermal Research , points out that the increase in the level of seismic activity in this volcano since December 2017 could indicate its possible awakening. To carry out a detailed investigation of this seismic process, the scientists installed four seismic stations in the vicinity to monitor the area for two months, from May to July 2018. Through the data obtained, they detected and located 559 seismic events in this area.
The international team of experts from Russia, Egypt and Saudi Arabia that has carried out the study does not know when an eruption could occur, but they believe that it could occur at any time and that it is possible that it is dangerous , as was the awakening of Vesuvius the year 79, which destroyed Pompeii after sleeping thousands of years.
