Encyclopedia of EarthThe Encyclopedia of Earth (EoE) is an electronic reference about the Earth, its natural environments, and their interaction with society. The EoE is a free, expert-reviewed collection of content contributed by scholars, professionals, educators, practitioners and other experts who collaborate and review each other's work. The content is presented in a style intended to be useful to students, educators, scholars, professionals, as well as to the general public. - See more at: http://www.eoearth.org/topics/view/51cbfc8bf702fc2ba812cc39/#sthash.bQzgJUH8.dpuf