Deep Sea Research Ocean Trenches Seafloor Studies Hydrothermal Vents Tectonic Activity Liquid Ocean Ocean-Recovered Materials Deep-Sea Sediment Records Deep Sea Exploration Deep-Sea Research Deep-Sea Exploration Tectonic Plates Deep Ocean Trench Studies Trench Systems Oceanic Trenches Hadal Trenches Marine Ecosystems Hadal Zone Habitability Deep Ocean Exploration Subsurface Oceans