Results from a CTD tow-yo over Mata Fitu in 2010. The bottom panel shows the CTD path over the volcano profile. Light-scattering values define the plume; red colors are the highest particle concentrations, blue colors are the lowest concentrations. The top panel shows the change in ORP values during the tow. Higher chemical concentrations are denoted by negative deflections in the ORP value. Image courtesy of NOAA Vents Program.