It has not seemed desirable to include many words that are rarely if at all used at present and which are in the older glossaries many words from fields closely related to ecology such as forestry, range management, agronomy, soils, and genetics are included because of their wide usage in ecological literature.The definitions are usually those that are in accord with present general usage. It has not seemed wise to attempt to pronounce judgment on the desira-bility of, or the need for, certain terms since decisions are made by usage as a language grows. The inclusion of certain words in this dictionary does not necessarily imply that the author approves or recommends their use.

This is the first textbook to cover the essential aspects of the topic at a level accessible to students. While focusing on applications in solid earth geophysics, the book also includes excursions into helioseismology, thereby highlighting the strong affinity between the two fields. The book provides a comprehensive introduction to seismic tomography, including the basic theory of wave propagation, the ray and Born approximations required for interpretation of amplitudes, and travel times and phases. It considers observational features while also providing practical recommendations for implementing numerical models. Written by one of the leaders in the field, and containing numerous student exercises, this textbook is appropriate for advanced undergraduate and graduate courses. It is also an invaluable guide for seismology research practitioners in geophysics and astronomy. Solutions to the exercises and accompanying tomographic software and documentation can be accessed online from www.cambridge.org/9780521882446.