Periodic Reporting for period 1 - PICVOLC (DePICting the interior of active VOLCanoes to reduce volcanic hazards: application to the present unrest at Nevado del Ruiz (Colombia) - PICVOLC)
Période du rapport: 2019-02-01 au 2021-01-31
The correct evaluation of hazards related to the prediction of volcano eruptions is essential to an effective preparedness of populations threatened by volcanoes. Our ability to predict future volcano eruptions is related to locating the source(s) of volcanic unrest and assess their evolution. This is why a better, more comprehensive understanding of changes/deviations of the magmatic system from the background activity is needed for better hazard preparedness.
Recent advances in Global Navigation Satellite System (GNSS), tilt, and Interferometric Synthetic Aperture Radar (InSAR) have greatly increased the availability of volcano deformation data. These measurements, combined with appropriate source models, can be used to estimate magma movement that precedes eruptions by detecting variations in the location, depth and volume of the magma intrusion. However, the models used to interpret the data are mostly based on oversimplified a-priori assumptions and there is a clear need for new physics-based models. Often, models of volcanic deformation that do not integrate different geodetic and geophysical datasets, lead to non-unique interpretations of the source of volcanic unrest because they are not sufficiently constrained. Studies that integrate independent datasets can provide a more comprehensive understanding of the deformation sources, while leading towards a more unique solution/interpretation.
PICVOLC project aims at combining many geophysical methodologies to reveal the internal structures of volcanoes, in particular of Nevado del Ruiz (Colombia), to support decisions to implement a monitoring network, and to identify possible sources of unrest signals that are detected at the surface.
By integrating geodetic and geophysical data as well as advanced Finite Element Method (FEM) numerical models into an inverse exploratory approach, PICVOLC aims at creating more accurate and constrained estimations of the active, inaccessible, and geometrically complex sources that could feed future eruptions. The aim is to provide a more robust estimation of deformation source parameters with reduced ambiguity. A less ambiguous interpretation of the nature, size, and shape of the source of unrest, brings strong benefits for society because it boosts our ability to interpret volcanic activity and to predict impending eruptions, possible volcanic hazards, and related risks for the population.
Recent advances in Global Navigation Satellite System (GNSS), tilt, and Interferometric Synthetic Aperture Radar (InSAR) have greatly increased the availability of volcano deformation data. These measurements, combined with appropriate source models, can be used to estimate magma movement that precedes eruptions by detecting variations in the location, depth and volume of the magma intrusion. However, the models used to interpret the data are mostly based on oversimplified a-priori assumptions and there is a clear need for new physics-based models. Often, models of volcanic deformation that do not integrate different geodetic and geophysical datasets, lead to non-unique interpretations of the source of volcanic unrest because they are not sufficiently constrained. Studies that integrate independent datasets can provide a more comprehensive understanding of the deformation sources, while leading towards a more unique solution/interpretation.
PICVOLC project aims at combining many geophysical methodologies to reveal the internal structures of volcanoes, in particular of Nevado del Ruiz (Colombia), to support decisions to implement a monitoring network, and to identify possible sources of unrest signals that are detected at the surface.
By integrating geodetic and geophysical data as well as advanced Finite Element Method (FEM) numerical models into an inverse exploratory approach, PICVOLC aims at creating more accurate and constrained estimations of the active, inaccessible, and geometrically complex sources that could feed future eruptions. The aim is to provide a more robust estimation of deformation source parameters with reduced ambiguity. A less ambiguous interpretation of the nature, size, and shape of the source of unrest, brings strong benefits for society because it boosts our ability to interpret volcanic activity and to predict impending eruptions, possible volcanic hazards, and related risks for the population.
During the Marie Curie fellowship, I performed a first land gravity campaign of the edifice of Nevado del Ruiz with measurements collected up to about 5000 m altitude in collaboration with the Colombian Geological Survey - Volcanological and Seismological Observatory of Manizales (OVSM). This campaign laid the foundations for a future set up of a geodetic network for the monitoring of temporal micro-gravity changes of the volcano that will contribute to a better knowledge of the life cycle of the volcano, and provide vital clues about timing and kind of eruption that may occur. With the collaboration of the group of Dr. Pasquale de Gori and Dr. Claudio Chiarabba (INGV - Rome) I developed a new up-to-date seismic tomography of the Nevado de Ruiz area and obtained a high-resolved model of the distribution of elastic material properties that was used to build a robust physics-based 3D FEM inverse model of the volcano. This updatable model can be used by the observatory to interpret the actual and future deformation signal of unrest of the volcano.
The results obtained give a better and up-to-date image, and thus a better understanding, of the internal structure of the volcano, a major goal for the observatories. This helps the observatory to interpret the ongoing unrest and future changes in the activity of the volcano. This is of paramount importance to help evaluate and predict the impact of the volcano activity on the infrastructures and population living around the volcano.