Book excerpt: Everything we see in our landscapes today was created by geological actions, all of them accompanied by earthquakes and volcanism. This thorough examination of the geology of the United States and its impact on people's lives explores the processes that shape the land surfaces of the United States. These processes act over long periods of time and are affected by such factors as wind, rain, and temperature. Readers will discover how they frequently catch us by surprise when unexpected events occur, as well as how we often ignore signals that indicate repeat disasters. The hazards associated with geological processes are a continuing concern, but readers will also discover the benefits of many of these so-called natural disasters. Geologic regions define the framework for the book. Gunn provides readers with an accessible overview of geology, defining such concepts as erosion and deposition and discussing such factors as the different kinds of rocks found in the earth's crust. He also explores the concept of plate tectonics in detail. Representative states have been selected to illustrate hazards and geologic features found over large areas, and students can discover those areas that are the most dangerous in which to live. Students are encouraged to draw on the resources provided for further in-depth study of the fascinating topics introduced and discussed.