A Novel Active Seafloor Pressure-Retained Multitube Sediment Corer

A novel minimally disturbed seafloor pressure-retained sediment corer driven by a self-served underwater fluid power system is presented. It features multiple independent two-stage cylinders with a piston rod to mount a core liner that can be penetrated into sediment and pulled back at a controllable speed. Each core tube is equipped with two ball valves to retain the in situ pressure of the seafloor sediment. The corer can be monitored in real time and controlled from the deck via a coaxial cable, such that operators onboard can choose the proper coring location, control the coring speed, and collect multitube pressure-retained cores in different sites during one deployment. The test prototype is equipped with only two tubes and deployed at a depth of 1,035 m in the South China Sea by the R/V Dayang No. 1 of China. Two tubes of sediment cores with in situ pressure retained have been successfully obtained.