Agustín Udías is Emeritus Professor at the Universidad Complutense, Madrid, Spain. He is the author of many papers about seismicity, seismotectonics of the Azores-Gibraltar, and the physics of seismic sources, and has also written several textbooks. Professor Udías has served as Editor-in-Chief of Física de la Tierra and the Journal of Seismology, and as the Vice-President of the European Seismological Commission. He is a member of the Accademia Europeae, the Seismological Society of America, the American Geophysical Union, amongst other societies, and is a Fellow of the Royal Astronomical Society.

1. Seismology. The science of earthquakes; 2. Earthquakes, Earth's structure and dynamics; 3. Instrumentation and digital data processing; 4. Basic concepts and equations of an elastic medium; 5. Waves in an infinite elastic medium; 6. Reflection and refraction; 7. Body wave propagation in layered media; 8. Ray theory. Media of constant velocity; 9. Ray theory media of variable velocity; 10. Ray theory spherical media; 11. Travel times and the structure of the Earth; 12. Surface waves; 13. Wave dispersion. Phase and group velocities; 14. Free oscillations of the Earth. Theory and observations; 15. Anelasticity and anisotropy; 16. Focal parameters of earthquakes; 17. Basic theory of earthquake mechanism; 18. The seismic moment tensor; 19. Simple models of fracture; 20. Methods of determination of source mechanisms; 21. Seismicity, seismotectonics, seismic risk, and prediction.