AbstractsEarth & Environmental Science

One of the most important tasks of modern volcanology, which represents a significant socio-economic implication, is to conduct hazard assessment in active volcanic systems. These volcanological studies are aimed at hazard that allows to constructing hazard maps and simulating different eruptive scenarios, and are mainly addressed to contribute to territorial planning, definition of emergency plans or managing volcanic crisis. The impact of a natural event, as a volcanic eruption, can significantly affect human life, property, infrastructures, and the environment. Long periods of quiescence are quite common in many volcanic areas and this often leads to a fall in the alert. The consequence is lack of preparation to deal with a volcanic crisis. The present Ph.D. Thesis is focused on the development and application of different tools for the spatial and temporal analyses to assess volcanic hazard in monogenetic volcanic fields. Monogenetic volcanic fields are commonly not regarded as potentially dangerous and only a few studies concerning hazard assessment have been conducted in such environments. In the long-term hazard assessment, we assume that the future eruptive behaviour in the volcanic field could be similar to the last eruptive activity. First, we have developed a new tool, QVAST (QGIS for VolcAnic SuscepTibility), designed to carry out the spatial analysis. This tool allows to calculate the volcanic susceptibility of the area, i.e. the probability of new vent opening, using direct and indirect structural data. Second, we have developed a new tool, HASSET (Hazard Assessment Event Tree), to conduct temporal analysis. Combining both tools and the previous one, VORIS 2.0.1, that uses simulation models to predict the most probable eruptive scenarios and which areas could be affected by a future eruptive event, we can evaluate in a probabilistic way long-term hazard represented by a qualitative hazard map that allows us to identify different levels of hazard in the study area. In this thesis we present different case studies. The first example was carried out at El Hierro Island (Canary Islands), an island essentially characterized by basaltic volcanism with both Strombolian and Hawaiian activity. The last eruption on El Hierro occurred in 2011–2012 demonstrates the importance of reliable data and tools that can enable scientific advisors and decision-makers to consider possible future eruptive scenarios. The second case study was Deception Island (Southern Shetland Archipelago, Antarctica), which is the most active volcano in the South Shetland Islands and has been the scene of more than twenty eruptions over the past two centuries. We identified a number of significant scenarios using our GIS-based tools and evaluated the potential extent of the main volcanic hazards to be expected on the island. The last case study presented is La Garrotxa Volcanic Field (NE of Spain), which is a quaternary volcanic field, located in the Northeast of the Iberian Peninsula, and includes more than 50 well preserved volcanoes. …