Publisher's Synopsis
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The interior structure of the Earth, similar to the outer, is layered. These layers can be defined by either their chemical or their rheological properties. The Earth has an outer silicate solid crust, a highly viscous mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core. This book studies the various layers or shells of Earth's crust including oceanic crust, continental crust, low-velocity zone, and core-mantle boundary. Project Webster represents a new publishing paradigm, allowing disparate content sources to be curated into cohesive, relevant, and informative books. To date, this content has been curated from Wikipedia articles and images under Creative Commons licensing, although as Project Webster continues to increase in scope and dimension, more licensed and public domain content is being added. We believe books such as this represent a new and exciting lexicon in the sharing of human knowledge.