Principles of Seismology / Принципы сейсмологии

A second edition of this textbook, first published 17 years ago, is a wonderful opportunity to review its contents and improve its pedagogical orientation, in view of the many comments and interactions received, teaching experience, and experimental progress in seismology over the intervening years. Seismology is the science of earthquakes, which are both natural disasters profoundly affecting human lives, and a subject of study through application of the principles of the physical sciences. These two aspects are linked, since an important aim of the study of seismology is to mitigate the terrible effects of earthquakes through a more complete knowledge of their nature. Seismology provides us also with a powerful instrument to study the constitution and dynamics of the Earth. To emphasize these different aspects of seismology, Chapter 2 has been added to present, as an introduction, the complex phenomenon of earthquakes from a narrative point of view. As a physical science, the fundamentals of seismology are based on analysis of the seismic waves produced by earthquakes and registered by seismographs. The importance of this aspect is shown by presenting the analysis of seismographic digital data in Chapter 3, so that it can be used in subsequent chapters. This is a unique feature not present in other texts on seismology. Thus, this approach has been used in the new edition. The text is at an introductory level for students in the last years of the European Licentiate and the first year of Masters programs or American upper-division undergraduate courses and first graduate courses, and at similar levels of study in other countries. As a first book, no previous knowledge of seismology, as such, is assumed of the student. The book's emphasis, as indicated by its title, is on the fundamental physical principles which constitute the basis of the analysis of seismic waves and their basic development. In consequence, a number of topics have been selected. It has been noticed that sometimes even graduate students lack a true grasp of the fundamental physical principles underlying some aspects of seismology. In this book, the most fundamental concepts are, therefore, developed in detail, with their mathematical developments fully worked out. Simple cases, such as one-dimensional problems and those in liquid media, are used as introductory topics. In some instances, more difficult subjects are introduced, although not fully developed. In these cases references to more advanced books and articles are given where they can be found. In each chapter, problems are proposed, some of them are fully solved in the electronic material. As an innovation in this edition, for some of the problems seismogram digital data are used, which are given in the electronic material. Details of websites from where data and programs can be retrieved are provided. The reader can access the electronic material at www.cambridge.org/UdiasBufom, and it is referenced in the text as EM. <...>