To understand timely issues such as natural disasters and environmental challenges-- and to evaluate solutions to related problems-- the average citizen needs a basic awareness of the scientific principles that influence our planet. This trusted book makes an often-complex subject accessible to readers with a strong focus on readability and illustrations. Offers a meaningful, non-technical survey that is informative and up to date for learning basic principles and concepts. Updates and revises art and illustrations to include dozens of new high-quality, photographs carefully selected to aid understanding and add realism. Provides a wealth of new special-interest boxes, including "Earth as a System," "People and the Environment," and "Understanding Earth." A useful reference for anyone interested in learning more about Earth's geology.