Novel Multitube Sampler for Collecting Pressure-Retaining Sediment Samples From the Abyssal Seafloor

For the demand of submersibles to carry out abyssal seafloor sediment pressure-retaining sampling operations at full ocean depth (operating water depth of 11 000 m), a full-ocean-depth submersible mechanical handheld sediment multitube pressure-retaining sampler with a pressure-retaining coring function was designed. A novel compensation-integrated pressure-retaining method is proposed for an in-situ hadal trench sediment sampler, in which each sampling tube has a volume of volume of 203 ml. In addition, computer simulations are used to analyze the sampling tube recovery process and show that an equivalent flow rate in the range of 0–6 m/s flows obliquely with better sediment desorption, and that the backwater side of the sampling tube is the dead center of sediment desorption. The sampler prototype was field tested at a depth of 7700 m in the West Philippine Basin and collected a sample of sediment with a pressure-retaining rate of 94%.