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...