Figure 10. Schematic of the seafloor assembly. All the equipment in this assembly is accessible to an ROV such as the one shown in Figure 11. Cables from the sensors grouted in ~1000 mbsf terminate in a 4-way underwater-mateable connector block. The data handling and instrument control package, marked "G," plugs into this connector block. A single output from the top of this package is coupled (by ROV) to the multiyear battery installed after the sensors are grouted. A data storage unit can be retrieved by an ROV when required.