Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 148.

Mid-ocean ridges play an important role in the plate-tectonic cycle of our planet. Extending some 50–60,000 km across the ocean-floor, the global mid-ocean ridge system is the site of creation of the oceanic crust and lithosphere that covers more than two thirds of the Earth's exterior. Approximately 75% of Earth's total heat flux occurs through oceanic crust, much of it at mid-ocean ridges through complex processes associated with magma solidification, heat transfer, and cooling of young oceanic lithosphere. While the majority of this heat loss occurs through conduction, approximately one third of the total heat loss at mid-ocean ridges is influenced by a convective process: hydrothermal circulation.