This leading dictionary - now in its third edition - offers wide-ranging and authoritative coverage of the earth sciences and related topics in 6,250+ clear and accessible entries. Coverage includes geology, oceanography, paleontology, minerology, volcanology, and planetary science as well asclimatology, geochemistry and petrology. It is an essential reference for students of geography, geology, and earth sciences and in related disciplines. The third edition is fully updated and includes additional coverage of process geomorphology and physical geography, plus more than 50 new line drawings to accompany descriptions of forms and processes. The new edition also includes entry-level web links, accessed via a regularly updated companionwebsite to ensure that links do not go out of date. The appendices include a revised geological timel scale, an updated bibliography, stratigraphic units, lunar and Martian time scales, wind-strenght scales, and SI units.