Source characterization for submarine metal resources

The Submarine Resources Research Center conducted a series of rapid and exhaustive mappings of submarine hydrothermal activities (Nakamura et al., 2015) that are potential sources of base-metals to be utilized in near future, according to the acoustic anomaly found in the water column (Kumagai et al., 2010)(Fugures 1 and 2). During the project, we mapped hydrothermal features around Japan (Figure 3) and confirmed that some of the roots of the anomaly are vigorous hydrothermal vents and characterized the hydrothermal activity (e.g., Miyazaki et al., 2017). In addition, we found that rare metal elements in ferromanganese crust are derived from the seawater itself (Amakawa et al., 2017)(Figure 4), and showed the distributions of REY-rich mud (Ohta et al., 2016). These basic studies can provide the nature of submarine metallic resources as common property for humankind and scientific fundamentals for SDGs.

Figure 1: Hydrothermal plumes were visualized as acoustic anomalies in the water column. An example of a Side-Scan-Sonar image (Kumagai et al. (2010)).

Figure 2: Hydrothermal plumes were visualized as acoustic anomalies in the water column. An example of a Multi-Beam Echo Sounder image (Nakamura et al., 2015)

Figure 3: Areas where hydrothermal activities were mapped using an acoustic method during 2015 (Nakamura et al., 2015)

Figure 4: Trace elements in ferromanganese crust directly originating from ambient seawater as indicated in the well=matched Nd-isotope composition at each depth (Amakawa et al., 2017)

Research Institute for Marine Resources Utilization (MRU)
Submarine Resources Research Center (SRRC)