Collection sediment from Mariana Trench with a novel pressure-retaining sampler

• Published in: Deep-sea research. Part I, Oceanographic research papers Vol. 183; p. 103740
• Main Authors: Wang, Hao, Ruan, Dong-Rui, Cao, Chen, Fang, Jia-Song, Zhou, Peng, Fang, Yu-Ping, Chen, Jia-Wang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2022
• Subjects: Hadal trenches; In-situ trial; Novel mechanism; Pressure-retaining; Sediment; Pressure-retaining; Sediment; Novel mechanism; Hadal trenches; In-situ trial
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/j.dsr.2022.103740

Sediments in the hadal trenches have been proved to contain a large number of specific microorganisms. In this study, we developed a pressure-retaining sampler for the hadal trenches. A novel piston sampling mechanism was designed, the weight of which is light enough to be mounted on a lander for field tests. Furthermore, laboratory tests validated its high-pressure resistance and pressure-retaining performance. We tested the penetration force and the sampling performance in different clays. Moreover, a pressure compensator was designed based on the actual gas state under high pressure. Finally, a prototype of the sampler was built and field tested in the Mariana Trench. The results indicated that the sampler has an excellent pressure-retaining capacity and can collect sediment samples at the deepest point of the in the world's ocean. •A novel self-sealing sampler for collecting sediment in hadal trenches is described.•Sediment samples obtained in the Mariana Trench were maintained at more than 80% of the in-situ pressure.•A new method for design of pressure accumulators is proposed based on the real gas state equation.•An automatic control system for a full-ocean depth sediment sampler is demonstrated.