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FIRE - Fogo Island volcano: multi disciplinary Research on 2014 Eruption
Fogo, in the Cape Verde archipelago, is one of the most active oceanic island volcanoes in the world – it has erupted approximately every 20 years since the island was discovered in the 15th century. The most recent eruption of Fogo volcano started on Nov 23, 2014, and a few days later the Collaboratorium for Geosciences (C4G), a consortium included in the National Strategic Research Infrastructure Roadmap, received a request of collaboration from Instituto Nacional de Meteorologia e Geofisica (INMGCV) to assist the instrumental observation of the eruption. The request was readily accepted, and FCT exceptionally funded a mission to Fogo to collect geological, seismic, geodetic, and geochemical data.
Hazard assessment – These rich datasets offer a unique opportunity to improve volcanic hazard assessment in the island and recommend on risk mitigation strategies. A recent study prepared for the United Nations Development Programme Office in Cape Verde (Fonseca et al., 2014) indicates that the present scenario – involving hawaiian/strombolianstyle eruptions through vents at the foot of Pico do Fogo – dominates volcanic hazard in the island.
Although other, less likely eruptive styles cannot be excluded, a significant improvement of hazard assessment can be achieved through a detailed analysis of this scenario. This mission will be achieved through:
- Improvement of the scientific knowledge of the plumbing system, through geological, morphostructural and geochemical investigations, complemented by microgravity surveying and seismic tomography;
- Thorough characterization of the 2014 eruption dynamics, through the analysis of the associated seismicity data and geodetic signature, complemented with field observation and remote sensing data;
- Lava flow modelling with a new digital elevation model derived with a UAV (drone), for a range of possible vent locations, associated with a probability density function derived from the previous eruptive history.
Transversal themes – The project’s activities converge into the following 3 transversal themes: i) volcanic structure (Past), ii) eruption dynamics (Present) and iii) strategies for risk mitigation (Future).
The results that feed into the three transversal themes are obtained through disciplinary tasks that facilitate in-depth knowledge exchange. In particular, the following activities are proposed:
a) detailed reconstruction of the eruptive and geological history of the volcano;
b) detailed imaging of the internal structure of the volcanic edifice;
c) imaging of the geometry and characterization of the feeding system;
d) analysis of surface deformation caused by the present eruption, in relation to density changes;
e) reconstruction and analysis of the succession of events (changes in eruptive style and rates) of the eruption and correspondent seismic signals;
f) mapping and detailed characterization of the surface topography and products created during the recent eruption;
g) investigation of the petrological/geochemical nature of the erupted products in relation to characteristics of the source region and processes of magmatogenesis;
h) understanding of the impact of the eruption on ecosystems (air, water and soils) and human health;
i) integration of existing knowledge into a comprehensive model of Fogo’s volcanic system;
j) analysis and modelling of hazards;
k) identification of strategies to better mitigate the risk associated with future eruptions.
Variety of techniques – In order to achieve the proposed goals, we rely on a variety of techniques spanning the fields of physical volcanology, geological mapping, remote sensing, seismology, spacegeodesy & gravimetry, igneous petrology & geochemistry, geochronology, palaeomagnetism, and numerical modeling. These techniques will be combined in coordinated and complementary ways, and will feed into the development of strategies for risk assessment and mitigation, in partnership with the competent authorities.
Holistic understanding – Besides contributing to hazard assessment, the anticipated results will also contribute to a holistic understanding of the Fogo volcano and of ocean island volcanoes in general. Notably, improved knowledge of the Fogo system will allow insight into the trigger mechanisms behind volcanic extreme events (low probability, high impact): In prehistorical times, Fogo generated several highlyexplosive (plinian) eruptions, and it was also the site of a catastrophic flank collapse that triggered a devastating giant tsunami (~73 kyrs ago).
Catalyser of integration – This project counts with a large team of Portuguese scientists, many of whom have a distinguished track record of work on Fogo and other volcanic systems. The project is the first joint scientific venture of the C4G community, serving as catalyser of integration between scientists and research groups within C4G, and between C4G and its strategic partners. In addition, the team includes scientists from Capeverdean institutions, aiming at an effective bilateral knowledge transfer.