Geosciences for risk and environment management
Study-unit Code
Geologia applicata alla salvaguardia e alla pianificazione del territorio
Maurizio Petrelli
  • Maurizio Petrelli
  • 42 ore - Maurizio Petrelli
Course Regulation
Coorte 2023
Learning activities
Attività formative affini o integrative
Academic discipline
Type of study-unit
Opzionale (Optional)
Type of learning activities
Attività formativa monodisciplinare
Language of instruction
Magma physical and physico-chemical properties are the key aspect of this course. Since the Earth's interior is not directly accessible, we have to assume compositions and structures by indirect means. In this concern, experimental petro-volcanology is a field of research that helps scientists to determine physical and chemical behaviors of rocks/magma and their constituents under high pressure and high temperature. Students will deal with such aspect with the hope to better understand processes like magma formation, composition, and evolution during its travel and to the surface.
Scientists use available experimental dataset (e.g. viscosity, diffusivity, solubility, phase equilibria, at various P-T-fO2 conditions) to interpret geodynamic processes. This lead to a better understands of eruptive dynamics and their environmental consequences and last but not least, provides indications to reconstruct the conditions at which magmas were formed. These aspects are of particular importance especially for volcanic hazard assessment and experimental studies allow simulating processes that are responsible for both effusive and explosive eruptions.
Reference texts
Lection's slides and teacher's notes.
Educational objectives
The main objective of this course is to provide the essential tools to properly describe magma physical and physico-chemical properties. The main knowledge gained will be:
- Knowledge on magma types;
- Knowledge of magmas formation’s dynamics;
- Understanding of the relationship between magma compositions and explosivity
- Knowledge of glasses and their characteristic
- Knowledge on crystallization kinetics of silicate melts
The main skills (i.e. the ability to apply acquired knowledge) will be:
- Set up and use viscosity, density and solubility models
- Knowing how to create glass from natural rocks or synthetic oxide powders.
- Knowing how link crystallization process and cooling rate.
The aim of the course is to introduce students to magma physical and physico-chemical properties. In order to understand how to apply the information and techniques described within the course, basic knowledge of mineralogy, petrography, and geochemistry are necessary. The knowledge of these disciplines is a prerequisite for the student planning to follow the course with profit.
Teaching methods
The course is organized as follows:
- Lectures on all subject presented in the program;
- Exercises on physical properties of magma (density, viscosity, solubility);
- Laboratory exercises on viscosity/density determinations.
Other information
Learning verification modality
The oral final evaluation will last about 20 min. The intention is to verify the student’s acquired knowledge on the theoretical and methodological topics reported in the program.
Moreover, it is aimed also to check the student’s communication ability and the use of correct terminology and language.
Extended program
- Experimental petro-volcanology: an introduction

- Volcanic eruptions

o Eruption stiles: Hawaian, Strombolian Vulcanian - explosive s.s. (Subplinian, Plinian and Ultraplinian)

- Some important magma’s properties

o Magma: a multiphase material
o Structures of silicate melts; the NBO/T parameter and its relevance on eruptive styles.
o Q-species concept in order to characterizes the connectivity of the silicate structure
o The glass transitions (Tg)
o Relaxation in silicate melts and relaxation time
o Magma classifications

- Physical characteristics of magmas and their importance in the study of magmatic processes

o Density
o Viscosity
o Diffusion
o Solubility

- Crystallization kinetics in silicate melts
o Intro
o From melt to glass
o Critical cooling rate
o TTT diangram (Time-Temperature-Tranformation)

- Experimental petrology techniques
o Furnaces
o Internally and externally heated gas pressure vessels
o Pyston cylinder
o Concentric cylinders
o Falling spheres methods for viscosity measurements
o FTIR-Karl Fischer Titration; -CS800- for volatile’s determinations (H2O e CO2)

- Petro-vulcanology lab.
o How to make glasses
o Viscosity measurements using analogue and natural magmas
o How create a viscosity model from laboratory dataset.
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