C8413 - SEISMOLOGY

Learning outcomes

At the end of the course, students acquire knowledge about the theoretical, computational, and data-processing aspects of seismology, focusing on the physics of seismic sources and the generation, propagation, and recording of seismic waves.

Course contents

Seismology represents one of the fundamental disciplines in the study of Earth Sciences, as it includes the study of the elastic and inelastic processes that characterize the Solid Earth and materials, at time scales ranging from microseconds to years.

The course provides the first elements of data processing and computational analysis of signals to the students of the CdS. The topics covered provide the first skills to work in an applied seismological environment, especially in research institutes and companies interested in the assessment of resources and seismic risk.

The course comprises computational laboratories that will provide the first training for students on software and programming languages used by the seismological community.

It is assumed that the student has a good preliminary knowledge of the basic concepts of thermodynamics, fluid mechanics and theory of elasticity.

Topics

The seismic source: description of the earthquake as seismic source, the spectrum of seismic waves, magnitude, energy and focal mechanism of earthquakes.

Seismic waves: propagation in inhomogeneous media, seismic rays in the Earth, surface waves and dispersion, absorption of seismic waves, elastic reflection and refraction.

Effects of earthquakes: the Earth's free oscillations, the change in the Earth's rotation due to earthquakes.

Seismic imaging techniques: seismic tomography; use of phase and amplitude information, interferometry and ambient noise tomography.

Readings/Bibliography

Reference Books

• T. Lay e T. C. Wallace, Modern Global Seismology, Academic Press, San Diego California US, 1995.

• K. Aki e P. G. Richards, Quantitative Seismology, 2a edizione, University Science Books, Sausalito CA, 2002.

Additional Books

• F. A. Dahlen e J. Tromp, Theoretical Global Seismology, Princeton University Press, Princeton NJ, 1998.

• E. Boschi e M. Dragoni, Sismologia, UTET, Torino, 2000.

• D. Gubbins, Time Series Analysis and Inverse Theory, Cambride University Press, Cambridge UK, 2004.

• H. Igel, Computational Seismology, A Practical Introduction, Oxford University Press Books, Oxford UK, 2017.

Teaching methods

Each lecture is accompanied by a PowerPoint presentation. The collection of files, organized by chapter, provides a comprehensive overview of the syllabus and can serve as a study resource for the course. These PowerPoint files are made available throughout the course via the course webpage.

The course includes computer-based exercises involving introductory programming in Julia, Matlab, and Python; active participation from attending students is expected during these sessions.

Assessment methods

The exam will be oral and will generally last about 30 minutes.

The student will be asked to analyse a portion of the seismogram, describing the components that constitute it and connecting it to the theoretical topics covered in the course.

The student will be asked in sequence to illustrate two topics, among those considered in the course. For each topic, the student will be first asked to expose the general framework, then to go into details on some specific aspects.

The student will be requested to know the main equations of the physical theories employed and to know how they are derived; to be able to apply them to specific cases; to know the orders of magnitude of the employed physical quantities.

Teaching tools

The course uses presentations connected to online resources, such as seismological databases and codes, which will contribute to the student's computational and data training.

The exercises include instructions given in advance for installing codes and downloading datasets on a personal computer, for in-class exercises and, optionally, outside of course time table.

Office hours

See the website of Luca De Siena