Acknowledgments -- Introduction -- Entries A-Z -- Feature essays: Coping with sea-level rise in coastal cities -- Gaia Hypothesis -- Desertification and climate change -- Earthquake warning systems -- Loma Prieta earthquake, 1989 -- Mississippi River Basin and the Midwest floods of 1927 and 1993 -- Age of the earth -- Formation of the earth and solar system -- Galveston Island Hurricane, 1900 -- Is there life on Mars? -- Lahars of Nevado del Ruiz, Colombia, 1985 -- History of ocean exploration -- World's oldest Ophiolite -- Homo Sapiens Sapiens and Neandertal migration and relations in the ice ages -- Is your home safe from radon? -- Why is seawater blue? -- Seismology and earth's internal structure -- Tsunami hazards -- Volcanoes and plate tectonics.