The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured these natural-color images of the waters off Namibia on February 13 and 15, 2015. Naturally occurring plumes of hydrogen sulfide were rising from the ocean floor and discoloring the sea surface.
Along the coast of Namibia, easterly winds push surface waters offshore and promote upwelling near the coast. Studies have described how bacteria in oxygen-depleted bottom waters off Namibia consume organic matter and produce prodigious amounts of hydrogen sulfide. As the gas bubbles up into more oxygen-rich water, the sulfur precipitates out and floats near the surface.
NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Caption by Mike Carlowicz.