SEISMOLOGY WITH LABORATORY

• SEISMOLOGY

The main objective of the course is to provide students with basic knowledge of earthquake physics, the effects of earthquakes and seismic risk assessment. The main knowledge acquired will be:

- theory of earthquake physics

- theoretical base on the concept of risk and in particular of seismic risk.

The main skills will be:

- ability to critically evaluate seismic processes and their associated hazard/risk;

- synthesis ability and the use of appropriate technical-scientific language.

• LABORATORY

Knowledge and skills in the field of instrumental seismology with particular reference to the ability to read and interpret seismic signals and to the methods of absolute and relative localization of earthquakes.

Frontal lectures will be held.

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.

Learning assessment may also be carried out on line, should the conditions require it.

SEISMOLOGY

Introductory concepts: scalar product, vector product, gradient, divergence, curl, seismogram, analog-digital conversion, spectral analysis, convolution, filters.

Stress and strain: stress tensor, strain tensor, elastic modules, Lamé constants.

Elastic waves: wave equation, body waves, surface waves, Huygens and Fermat principles, Snell's law, Zoeppritz-Knott equations, reduction of seismic amplitude with propagation, diffraction, normal modes.

Earthquake source: elastic rebound, seismic cycle, focal mechanisms, moment tensor, source spectra, stress drop.

Earthquake size: definition of magnitude, magnitude of local events, magnitude of distant events, saturation of magnitude, moment magnitude, energy, intensity.

Hypocentral location: single station, multiple stations, relative locations.

Instruments: site and instrument selection and relative installation.

Earthquakes and statistics: Gutenberg-Richter's law, Omori's law, Bath's law.

Particular types of seismicity: induced, CTBTO, planetary.

Earthquake prediction and stress transfer: earthquake cycle, precursors, static stress, dynamic stress.

LABORATORY

Reading of seismograms. Electromagnetic seismometers. Epicentral locations. Estimation and calculation of the magnitude. Hypocentral locations. Residuals of station and RMS. Related calculation programs. Seismic signal analysis: particle motion and polarization.

1.      Stein, S., Wysession, M. (2003). An Introduction to Seismology, Earthquakes, and Earth Structure. Blackwell Publishing.

2.      Shearer, P. M. (2011). Introduction to Seismology, 2nd edition. Cambridge.

3.      Lay, T., Wallace, T.C. (1995). Modern Global Seismology. Academic Press.

4.      Treatise of Geophysics, 2nd edition (2015). Elsevier.

5.      Kramer, A.L. (1996). Geotechnical Earthquake Engineering. Prentice Hall College.

6.      New Manual of Seismological Observatory Practice (NMSOP-2). http://bib.telegrafenberg.de/publizieren/vertrieb/nmsop/

7.      Havskov, J., Ottemoller, L. (2010). Routine Data Processing in Earthquake Seismology. Springer.

8.      Kearey et al. (2002). An Introduction to Geophysical Exploration. Blackwell Editore.

9.  Gasparini e Mantovani - Fisica della terra solida - Liguori editore

10.      Dispense.

SEISMOLOGY

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 electronically, should the conditions require it.

LABORATORY

The exam consists in reading the paper or computer seismograms using suitable software to ascertain the level of knowledge and interpretation skills in the field of instrumental seismology.

Verification of learning can also be carried out remotely, should the conditions require it.

SEISMOLOGY

Talk about the stress and strain tensor.

What is the elastic tensor and how many components is it made of?

Talk about spectral analysis.

What is convolution and why is it behind filters?

What are the Zoeppritz-Knott equations?

Illustrate the mechanisms of reduction of the seismic amplitude with the distance from the source.

What are the focal mechanisms?

How can we derive the theoretical spectra of earthquakes?

What is stress drop?

What are the assumptions on the basis of the magnitude scales?

Illustrate the concept of magnitude saturation.

What are the differences between absolute and relative locations?

What is the frequency response of an instrument?

Explain how to choose the type of seismometer to install and the site in which to install it.

What is the Gutenberg-Richter law?

Illustrate the internal structure of the Earth as suggested by seismological data.

Talk about the seismic signals that can be recorded in a volcanic environment.

What are the differences between static and dynamic stress transfer.

What is meant by seismic risk.

LABORATORY

Reading of seismograms and picking.

Mechanical and electromagnetic seismometers.

Richter magnitude, local and duration magnitude of an earthquake.

Simplified epicentral locations.

Hypocentral locations