A robotic arm places a white square grid over dark nodules on a sandy deep-sea floor.
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Grid to Measure Nodule Abundance
During the fourth dive of the 2026 American Samoa ROV + Mapping Exploration expedition, the team placed a grid, 25 x 25 centimeters (10 x 10 inches), on the seafloor to measure nodule abundance. The team then collected nodules from this area using a scoop.
Credit

NOAA Ocean Exploration, 2026 American Samoa ROV + Mapping Exploration