LEARNING OUTCOMES

The scope of the course is to provide the student with a basic knowledge of the physics behind the seismic process, through the examination of the relation between seismicity and faults. The topics discussed during the course will allow understanding why, where, and when earthquakes occur.

AIMS AND LEARNING OUTCOMES

The participation in the planned activities will allow the student to understand the mechanisms governing earthquake generation. Specifically, students will acquire knowledge in fracture mechanics and earthquake physics. They will learn to interpret earthquakes as the result of complex physical processes of fault interaction in space and time.

PREREQUISITES

Students are expected to know the following topics of structural geology: 1) deformation mechanisms; 2) classification of faults and shear zones; 3) classification of fault rocks.

TEACHING METHODS

The course consists of lectures delivered through multimedia presentations and computer exercises.

Lectures of the first semester will be carried out in classroom, if possible. However, online streaming and video recording (synchronous or asynchronous) will be guaranteed. Likewise, practical activities will take place in laboratory, with multiple shifts if necessary. All classroom and laboratory activities will be carried out in compliance with the capacity limits of the classrooms / laboratories and the distance required by current legislation following the emergency COVID19.

Please refer to AulaWeb for further informations about the measures for the prevention and management of the epidemiological emergency caused by Covid-19

SYLLABUS/CONTENT

1) Introduction: where and why earthquakes occur; earthquakes in the world and relationship with terrestrial geodynamics; the contribution of geodesy to the understanding of seismic activity.

2) Fracture mechanics: fracturing criteria (Griffith theory, Mohr-Coulomb criterion, and Byerlee law); fracture dynamics (modes and patterns of fracture propagation); rock friction (asperity and barrier models; dependence of friction force on composition, pressure, temperature, presence of fluids, and slip velocity) and friction laws; dynamics of stick-slip (stick-slip vs stable sliding; stress drop; equation of motion); fault interaction and fault populations (scaling laws and self-similarity).

3) Earthquake mechanics: magnitude; seismic moment and energy; focal mechanisms; scaling laws (Gutenberg & Richter's law for single sources and groups of faults; characteristic earthquake model).

4) Phenomenology of earthquakes: seismic sequences and swarms (definition of aftershock, foreshock, and discussion of case studies); role of dilatancy and diffusion of fluids in the seismic process; earthquake interaction (static vs dynamic triggering; Coulomb failure criterion with practice exercise); seismic cycle and earthquake recurrence models.

During the lessons, basics of earthquake prediction will be provided: meaning (prediction vs. forecasting); short, medium, and long term forecasting, precursor phenomena.

RECOMMENDED READING/BIBLIOGRAPHY

All teaching material used during the lectures will be available on AulaWeb.

Scholz, C. H. The Mechanics of Earthquakes and Faulting, Third Edition. Cambridge University Press (2019).