55342 - Complements of Earth Physics

Learning outcomes

At the end of the course, the student acquires a good knowledge of basic aspects of physics of the Earth and of the associated research methods: in particular, the Earth’s gravity field and isostatic equilibrium, the Earth’s magnetic field, gravimetric and magnetotelluric methods.

Course contents

The course is made of two modules of 3 credits each:

1) The Earth’s magnetic field (prof. Michele Dragoni).

Phenomenology of the geomagnetic field. Physical properties and dynamics of the Earth’s core. Foundations of magnetohydrodynamics. The geodynamo. Foundations of plasma physics. The ionosphere and the magnetosphere. Magnetic properties of rocks. Elements of magnetometry and magnetotellurics.

2) The Earth’s gravity field (prof. Maria Elina Belardinelli).

Gravitational field equations. The distribution of density in a spherically symmetric Earth. Expansion of gravitational potential in spherical harmonics. Earth’s gravity potential. Geoid. Reference potential and ellipsoid. Potential anomalies and geoid heights. Elements of gravimetry. Reduction of gravity data. Gravity anomalies. Isostasy. Compensation depth and models. 

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

Readings/Bibliography

Each lesson is accompanied by the projection of a file PowerPoint. The set of files, divided into chapters, contains an exhaustive treatment of the program and can be used as a textbook for the study of the subject. The files in pdf format are available since the beginning of the course and can be reached from the web page of the course.

If they wish to go deeper into the topics of the first module of the course, students may consult the following textbooks:

- R. Lanza and A. Meloni, The Earth’s Magnetism, Springer-Verlag, Berlin, 2006.

- W. A. Campbell, Introduction to Geomagnetic Fields, Cambridge University Press, Cambridge, UK, 2003.

- P. A. Davidson, An Introduction to Magnetohydrodynamics, Cambridge University Press, Cambridge, UK, 2001.

- P. Melchior, The Physics of the Earth’s Core, Pergamon Press, Oxford, UK, 1986.

The textbooks are available in the Library of the Department of Physics and Astronomy (Sector of Geophysics, viale Carlo Berti Pichat 8).

Teaching methods

Classroom lectures with projection of files PowerPoint from computer or with overhead projector.

Assessment methods

The exam will be oral and will generally last about 45 minutes. It will concern for one half the topics of the first module and for the other half the topics of the second module: the overall evaluation will weigh the two parts equally.

The student will be asked in sequence to illustrate a few 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 worked out; to be able to apply them to specific cases; to know the orders of magnitude of the employed physical quantities.

Teaching tools

Computer and projector.

Office hours

See the website of Michele Dragoni

See the website of Maria Elina Belardinelli