A new method for investigating seabed sedimentation processes based on submarine electric field characteristics

Seabed erosion and deposition pose critical challenges to submarine infrastructures and benthic ecosystems, underscoring the need for reliable long-term monitoring. Conventional techniques primarily capture periodic sedimentation data and fail to quantify continuous erosion rates. This study introduces a novel self potential (SP) based method that exploits SP differences between sediment and seawater to monitor seabed morphological changes. In situ experiments conducted at Ningbo Daxie Wharf achieved continuous 110 day observations from February to June. Distinct SP variations corresponding to siltation processes were identified, enabling the determination of seabed interface evolution. Inversion of suspended sediment concentration revealed a Gaussian AMP functional relationship between SP and sediment concentration, modulated by temperature, salinity, depth, and particle type. A change point detection model based on SP achieved 1 cm precision in identifying interface variations. Long-term monitoring indicated a total deposition of 46 cm, averaging 0.67 cm/d, the monitoring threshold was determined to be 0.7 cm/d, while stratified layers exhibited a sinusoidal relationship between SP and vertical sediment flux. These findings demonstrate that SP responses can effectively quantify erosion-deposition dynamics, offering a robust approach for seabed morphological monitoring and providing valuable implications for dredging and marine engineering design.