The Subseafloor Biosphere At Mid

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 144.Awareness has grown over the past several years that the subseafloor may harbor a substantial biosphere sustained by volcanic heat and chemical fluxes from the Earth's interior. This realization has profound scientific implications for questions concerning the origins of life, the true extent of Earth's biosphere, and the search for life on other planets. At mid-ocean spreading centers, the fluxes that sustain life are the highest, and the hydrothermal fluids in which micro-organisms grow are readily accessible on the seafloor. In addition, periodic volcanic eruptions flush fluids and microbes from the subsurface, and volcanic gases are believed to drive spectacular microbial blooms. Although ridges are challenging locations in which to work, they are unique in the oceans because of the diversity and dynamic nature of their subsurface environments.