Laboratory modelling of caldera collapse in volcanic systems
Caldera collapse is a catastrophic event often associated with a large volcanic eruption: the drainage of large volumes of magma from subsurface reservoirs leads to the collapse of the volcanic edifice, resulting in large circular depressions at the surface.
Good examples of caldera collapse are Santorini and the myth of Atlantic, the AD 79 Mount Vesuvius eruption and the destruction of Pompei, and the gigantic 1991 eruption of Pinatubo, Philippines. Even if numerous volcanic eruptions occurred during the XX century, only a few (5-6) lead to caldera collapse, such that direct observations of caldera collapse are lacking. Consequently, the physical conditions of (1) the onset of caldera collapse and (2) the structural development of collapse calderas are very poorly understood.
The aims of this MSc project are to explore the physical parameters that control the onset of caldera collapse and quantify the structural evolution of calderas.
The project is based on a state-of-the-art laboratory apparatus that simulates caldera collapse in the laboratory. The crust is modelled with fine-grained granular material, and the magma is modeled with silicone putty.
The experiments consist of a reservoir of silicone within a box filled with the granular material. The drainage of the silicone reservoir triggers the collapse of the model surface. The surface evolution of the models is monitored using a photogrammetric system, which produces high-resolution and high-precision measurements of the caldera evolution.
The project will be organized according to the following steps:
- Initiation to the modelling technique during the GEO4151 course: “Earthquake and volcanic processes”;
- Running a selected series of experiments and data acquisition;
- Data analysis using in-house image analysis tools;
- A physical interpretation of the models, and integration with the numerical models of the numerical MSc project (if implemented).
The learning outcomes are the following:
- Modelling strategy;
- Quantitative data and physical analysis;
- Physics of rock stability, which is applicable to other geological systems (landslides, avalanches, geotechnics);
- Multi-disciplinary work.
To implement this project, it is recommended to have:
- Basic knowledge in programming skills, in order to analyze the laboratory data;
- Basic knowledge in brittle rock mechanics.
The skills to be acquired during this MSc projects are highly relevant both for academic, geotechnical and consulting careers.