Geophysical and geochemical survey across El Hierro (Canary Islands) during the 2011-2012 monogenetic eruption

Abstract

Enhancing volcanic risk assessment and developing new methodologies for volcanic activity are among the main challenges in Geosciences. In the field of Volcanology, it depends directly on our understanding of when, where, and which type of volcanic eruptions will take place. In the case of polygenetic volcanoes the emphasis is usually on “when will the eruption take place? In the case of the monogenetic volcanism, while a certain monotony exists in the composition of magmas from an eruption and another, we can observe a huge diversity in the eruptive dynamics inside a volcanic field and sometimes for a single edifice (e.g. Smith and Nemeth, 2017), switching from low-energy lava flows to violent hydromagmatic explosions. As a consequence, understanding which type of eruption we can expect is crucial. Contrary to polygenetic volcanoes, for which the eruptive activity is mostly centered on the edifice, the magma can reach the surface almost anywhere in a monogenetic field, depending on tectonics, local geology, etc. Knowing where the next eruption will take place becomes a big challenge as well. In any case, some major issues consist in (1) understanding the local features affecting the triggering of eruptions and the volcano dynamics, (2) understanding which of the measurable parameters are relevant for the observation of monogenetic activity, and (3) implementing observation methods adapted to monogenetic fields.