A new method for long-term in situ monitoring of seabed interface evolution: A self-potential probe

The evolution of the seabed interface is associated with various issues such as sediment accumulation at ports, erosion of shorelines, scouring of soil around bridge piles, deep-sea mining, and deformation of the seafloor. In order to gain insight into the evolution of seabed elevation and the status of seabed engineering structures, in-situ monitoring of the seabed interface is necessary. This paper presents a long-term in-situ monitoring method of seabed interface changes based on self-potential measurements. A sensor-free self-potential in-situ monitoring probe was developed, which has a vertical measurement range of 1 m and a resolution of 2 cm. Laboratory and in-situ test results show that the self-potential probe can identify the seabed interface, the interface between seawater and atmosphere, and the interfaces of different types of sediments. Even when the seabed surface is covered with polymetallic nodules, the seabed interface can still be identified and the layers of polymetallic nodules can be distinguished. This study contributes to a deeper understanding of self-potential measurements and provides a new technology for in-situ monitoring of the seabed interface.