Ocean Ridges and Trenches immerses readers in the mysteries of the world's sea floors, from the surprising creatures of the Galapagos Rift to the devastating tsunamis of the Java Trench. This new volume in ''The Extreme Earth'' set reveals how 10 undersea mountain ranges and valleys came to be, how and why it has changed over the span of geologic time, and its contributions to the environment. The ridges and trenches covered span the Mariana Trench, the deepest point in the ocean, and the San Andreas Fault, site of many of California's earthquakes. Each chapter provides illuminating material on environmental challenges and expert reports on science in action, with details on field studies conducted at each sea-floor site. Additional articles cover related high-interest topics, such as giant squids, magnetic fields, and plate tectonics. This book is supported with photographs and line illustrations, a glossary of scientific terms, and suggestions for finding further information.