This new edition includes 10,000 entries which cover all areas of geoscience, including planetary science, oceanography, palaeontology, mineralogy and volcanology. In this edition, 675 new entries have been added, and include expanded coverage of planetary geology and earth-observing-satellites. Other new entries terms such as Ianammox, Boomerangian, earth rheological layering, and metamorphic rock classification. The entries are also complemented by more than 130 diagrams and numerous web links that are listed on a regularly updated dedicated companion website. Appendices supplement the A-Z and have been extended to include three new tables on the Torino Impact Hazard Scale, Avalanche Classes, and the Volcanic Explosivity Index. The list of satellite missions has also been revised and updated to include recent developments. A Dictionary of Geology and Earth Sciences is an authoritative, and jargon-free resource for students of geology, geography, geosciences, physical science, and those in related disciplines. Preface A-Z entries Stratigraphic Units As Defined In The North American Stratigraphic Code, 1983 Time-Scales Wind Strength Si Units, Conversions, And Multiples Volcanic Explosivity Index (VEI) Torino Impact Hazard Scale Avalanche Classes Satellite Missions Michael Allaby has written many books on environmental science and especially on climatology and meteorology. These include the Encyclopedia of Weather and Climate; The Facts On File Weather and Climate Handbook; and the DK Guide to Weather. He is the General Editor of the Oxford dictionaries of Ecology, Zoology, and Plant Sciences.