The fourth edition of Physics of the Earth maintains the original philosophy of this classic graduate textbook on fundamental solid earth geophysics, while being completely revised, updated, and restructured into a more modular format to make individual topics even more accessible. Building on the success of previous editions, which have served generations of students and researchers for nearly forty years, this new edition will be an invaluable resource for graduate students looking for the necessary physical and mathematical foundations to embark on their own research careers in geophysics. Several completely new chapters have been added and a series of appendices, presenting fundamental data and advanced mathematical concepts, and an extensive reference list, are provided as tools to aid readers wishing to pursue topics beyond the level of the book. Over 140 student exercises of varying levels of difficulty are also included, and full solutions are available online at www.cambridge.org/9780521873628.