Physics of volcanism
Academic Year 2022/2023 - Teacher: ANDREA CANNATAExpected Learning Outcomes
Provide knowledge and skills in the field of volcanology with particular reference to the physical processes that occur in a volcanic environment, including the genesis of magmas, their rise and eruptive dynamics. This information is fundamental for the assessment of the volcanic hazard and therefore the mitigation of the risk.
Knowledge and understanding:
- theoretical bases on the physics of magma genesis processes and its ascent;
- theoretical bases on the physics of eruptive processes;
- theoretical bases regarding the main methods of volcano monitoring and assessment of volcanic hazard.
Ability to apply knowledge and understanding:
- ability to analyze pre-eruptive and syn-eruptive processes;
- ability to analyze volcanic monitoring systems and data.
Autonomy of judgment
- ability to argue personal interpretations of volcanic phenomena with particular reference to the physical processes underlying them.
Communication skills
- ability of expository synthesis and use of appropriate technical-scientific language.
Course Structure
Face to face.
Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.
Required Prerequisites
To understand the topics covered in the teaching, the knowledge of basic notions of mathematics, physics and volcanology is important.
Attendance of Lessons
Mandatory.
Detailed Course Content
Origin of magmas: structure of the Earth, mantle melting processes, melt migration.
Magma chambers: evidence for magma storage within the crust, magma crystallization, heat transfer and magmatic intrusions, crustal stresses and magma chambers, magma chamber convection, magmatic systems as mush columns.
Magma migration: thermodynamic and transport properties of silicate melts and magma, porous flow model of melt migration, permeability, mechanical properties of the matrix, melt localization and flow focusing, rates of magma ascent and storage, magma transport in dikes, dynamics of magma ascent in the volcanic conduit.
Lava flows: origin of lava flows, lava flow dynamics, lava flow heat budget and cooling, lava flow modelling.
Strombolian eruptions: slug-bubble formation, ascent of a gas slug, burst of a gas slug.
Vulcanian eruptions: eruption initiation, vent conditions, shock waves, pyroclastic phase.
Sustained explosive activity: physical processes, quantitative modeling of eruption columns, atmospheric dynamics, basaltic systems and lava-fountaining eruptions.
Modeling tephra sedimentation from volcanic plumes: plume dynamics and particle sedimentation, empirical and analytical models used for the characterization of tephra deposits, models based on the Advection–Diffusion–Sedimentation (ADS) equation, limitations of input parameters and parameterizations adopted by ADS models, case study.
Pyroclastic density currents: PDCs generated by various mechanisms, insight from Recent Eruptions, PDCs - encompassing a range of particle concentration, buoyancy reversal, temporal evolution of particle concentration, erosion, anatomy of a pyroclastic density current.
Volcano seismology: classification, model of occurrence of volcano seismic signals, volcano seismology in laboratory, infrasound, seismo-volcano monitoring, volcano seismology at Mt. Etna.Textbook Information
1. Parfitt and Wilson (2008). Fundamentals of Physical Volcanology. Blackwell.
2. Sigurdsson et al. (2015). The Encyclopedia of Volcanoes, 2nd Edition. Academic Press.
3. Fagents et al. (2013). Modeling Volcanic Processes. Cambridge University Press.
4. Lecture notes.
Course Planning
| Subjects | Text References | |
|---|---|---|
| 1 | Origin of magmas | Fundamentals of Physical Volcanology. Cap. 2. The Encyclopedia of Volcanoes. Cap. 1. Notes |
| 2 | Magma chambers | Fundamentals of Physical Volcanology. Cap. 4. The Encyclopedia of Volcanoes. Cap. 8. Modeling Volcanic Processes. Cap. 2. Notes. |
| 3 | Magma migration | Fundamentals of Physical Volcanology. Cap. 3. The Encyclopedia of Volcanoes. Cap. 2, 5, 9, 10, 11. Modeling Volcanic Processes. Cap. 3, 4. Notes. |
| 4 | Lava flows | Fundamentals of Physical Volcanology. Cap. 9. Modeling Volcanic Processes. Cap. 5. Notes. |
| 5 | Strombolian eruptions | Modeling Volcanic Processes. Cap. 6. Notes |
| 6 | Vulcanian eruptions | The Encyclopedia of Volcanoes. Cap. 28. Modeling Volcanic Processes. Cap. 7. Notes. |
| 7 | Sustained explosive activity | The Encyclopedia of Volcanoes. Cap. 28. Modeling Volcanic Processes. Cap. 8. Notes. |
| 8 | Modeling tephra sedimentation from volcanic plumes | Fundamentals of Physical Volcanology. Cap. 8. The Encyclopedia of Volcanoes. Cap. 33. Modeling Volcanic Processes. Cap. 9. Notes. |
| 9 | Pyroclastic density currents | The Encyclopedia of Volcanoes. Cap. 35. Modeling Volcanic Processes. Cap. 10. Notes |
| 10 | Volcano seismology | Notes |
Learning Assessment
Learning Assessment Procedures
The exam consists of an oral test of about 30 minutes aimed at ascertaining the level of knowledge and understanding reached by the student on the theoretical and methodological contents indicated in the program. Students will begin the exam with the presentation of a topic of their choice.
Verification of learning can also be carried out remotely, should the conditions require it.
Examples of frequently asked questions and / or exercises
What are the main mechanisms of magma formation?
Talk about heat transfer processes in magma chambers.
What are the main thermodynamic and transport properties of silicate melts?
How does the transport of magmas into the dikes take place?
Talk about modeling lava flows.
What is a gas slug and how do the formation and rising processes of the slugs take place?
What are shock waves?
Talk about the physical processes underlying sustained explosive activity.
Talk about pyroclastic density currents and their "anatomy".
What are the main seismic signals that are recorded in a volcanic environment?