Numerical simulation of basaltic lava flow from Mount Etna

The project is the result of our Research Initiation Thesis about the 2001 lava flow that extended over 6.4 km from the eruptive crack located at 2100 m on the southern side of Mount Etna, in Sicily. That project is part of a long-term project aiming to let know risks linked to the volcanic activity of the region, based on numerical simulation methods. It follows on from one’s MALAVAL and PINSON (2019) Project. The 2020 project involves studying the first kilometer of this lava flow in order to reduce the very high computation times. Through the project, we would like to simulate as detailed as possible the flow dynamics of lavas eject from adventive craters using Dassault Systemes® SIMULIA XFlow software. The final goal is to know precise parameters describing that lava flow type, in order to predict at best the trajectory of potential new flows. The long-term goal is that these numerical simulations improve the volcanic risk prevention represented by Etna for population and neighboring human infrastructures. Indeed, it can be a pre-eruptive predictive device, adaptable to each type of eruption from Etna. The evolution of the project was meant to be in four steps :

• First, a two-week field campaign to collect chemicophysical data, and to acquire photogrammetry data, in order to recreate the field topography of the first kilometer of the lava flow.  
• Second, the recreation of the field topography with Agisoft Metashape Professionnal. The DEM (Digital Elevation Model) obtained has a precision of 10 cm.  
• Third, the adaptation of the DEM with Dassault Systemes® CATIA, to create a closed environment and allow an internal flow of lava.  
• Fourth, repeated simulations with XFlow, with the new model allowing a far better precision than the one from MALAVAL and PINSON (2019) Project.

Unfortunately, due to Covid-19 problems and confinement, the modelling step with CATIA is hardly pursuable, so we currently reuse MALAVAL’s and PINSON’s model. The results obtained are quite representative for some, but the precision and thickness of the trajectory as well as the precision of the lava flow between ripples still needs to be improved. More improvements are to be made in the months to come. The research approach began with a two-week field campaign to collect chemicophysical data about the lava flow. The study of these parameters as well as the bibliographic research allowed us to propose different periods and walks for lava flow in the study area. After which, the photogrammetric campaign of first kilometer enabled us to obtain a DEM (Digital Elevation Model), i.e. the topological representation of the current area. Subsequently, we wanted to create a new closed environment under CATIA to allow an internal flow of lava with more precision that the one from MALAVAL and PINSON (2019) Project. Once this geometry had been created, it would have been possible to export it to XFlow. Unfortunately, due to Covid-19 problems and confinement, the project cannot be pursued further, so we currently reuse MALAVAL’s and PINSON’s model. The results obtained are quite representative for some, but the precision and thickness of the trajectory as well as the precision of the lava flow between ripples still needs to be improved. More improvements are to be made in the months to come. The Dassault Systemes® 3DEXPERIENCE® platform has been used several times to share our information and communicate with the other student teams working at GéoLab UniLaSalle.