Map of particle intensity from a light backscattering sensor mounted on ABE. Higher concentrations of particles (higher NTU values) help identify locations of hydrothermal vents. ABE surveys are conducted close to the seafloor where rising particle plumes are less diluted and spread out, compared to CTD surveys which show how far the plumes can spread and how greatly the ocean can be impacted by hydrothermal activity. Image courtesy of Submarine Ring of Fire 2002, NOAA/OER.