Turbulence is vital for life, also in 2500-m deep Mediterranean waters. Yearlong observations with about 3000 high-resolution temperature sensors show: About half the time, relatively warm stratified waters are moved from 100’s of meters higher levels to near the seafloor. These internal-wave and eddy-induced motions are three times more turbulent than those induced via general geothermal heating from below, and about ten times more turbulent than those from open-ocean processes.