Magma steadily emerges between oceanic plates. It pushes the plates apart, builds large underwater mountains and forms new seafloor. This is one of the fundamental processes that constantly change the face of the Earth. But there are also times when new seabed is created without any volcanism, by un-roofing mantle material directly at the seafloor. Scientists led by GEOMAR, Germany have published the first estimation based on seismic data on how much seafloor is produced this way.