The early stages of releasing sediment plumes are characterized by the turbulent wake generated by the deep-sea mining vehicle (DSMV), which is usually discharged mixed with the plumes, greatly influencing the evolution of the plumes. This study adopted a regular cube structure with a tail jet to quantify the dynamic interactions between DSMV and sediment plumes. The movement of DSMV and the plume release occur simultaneously at a fixed velocity in opposite directions. This study is concerned with the effect of the relative dimension of DSMV on the sediment plumes on small scales (t ≤ 2 s), contributing to a focus on the vital physical mechanics of controlling the extent of these plumes.
The vast expanse of the deep oceans is a treasure trove of resources on Earth, containing huge reserves of solid mineral resources, including polymetallic nodules, cobalt-rich crusts, and polymetallic sulphides (Sharma, 2017). These resources have a wide variety, vast reserves, high grades, and significant development and utilization prospects (Jianmin Yang, 2020). Research on the development of deep-sea mineral resources began in the late 1950s, with the United States, Europe, Japan and other countries and regions mainly focusing on deep-sea polymetallic nodules and studying their respective exploration and commercial exploitation schemes (Mero, 1965, Chung, 2005). In the 1980s and 1990s, the South Korea, India and China also joined the deep-sea mineral resources development team, exploring systematic solutions and commercial mining options (Chung, 2009). In recent years, countries around the world have carried out single and integrated sea trials, and deep-sea mineral resources development technology and equipment have made significant progress (Klein, 1993; Koschinsky et al., 2018; Kulkarni et al., 2018; Spearman, 2015; Muñoz-Royo et al., 2022).
Since the 1970s, the United States has taken the lead in conducting a series of the Deep Ocean Mining Environmental Study (DOMES) (Horn et al., 1973; Ozturgut, 1978; Burns et al., 1980). Subsequently, the European Union, Germany, Japan and other countries and regions successively conducted experiments on the disturbance and impact of the bottom of deep-sea mining (Karbe et al., 1981; Foell et al., 1990; Chung and Tsurusaki, 1994; Fukushima, 1995; Shirayama, 1999). Through this series of experiments, it was found that more than 20 environment influences have been found in deep-sea mining activities, mainly in the two depth zones. The first region is near the collector mining trajectory, and the other on the seabed is on the ocean surface or upper layer near the tailings discharge point, which forms a so-called collector plume and midwater plume, respectively (Ouillon et al., 2022a). Along with deep-sea mining activities, these two types of sediment plumes can spread, driven by ocean currents, affecting benthic communities, and causing wide-range, long-cycle environmental impacts on the marine environment. The collector plume, known as a sediment plume, is generated by resuspended sediments discharging around a collector vehicle during deep-sea mining activities, generally in its wake zone (Ouillon et al., 2022b), which is also the primary concern in this study. Indeed, as the plume approaches the seabed from the beginning, the seafloor disturbance rate plays a significant role in the extent of the plume, disturbed sediment estimation, trajectory and residence time of the suspended deposited particles, and its potential environmental impact.
