3. Various deep-sea bottom types observed at the North Atlantic Vema Fracture Zone: A) Flat sea bottom covered with almost intact Sargassum leaves (~5000 m); B) Flat sea bottom showing bioturbation caused by benthic animals; C) Seabed covered with manganese nodules; D) Basalt rocks at the Mid-Atlantic Ridge area; E,F) Seafloor exhibiting non-regular ridges; G) Regular ridges, which can be an indication of bottom hydrodynamics. © Nils Brenke.