Hydrogen sulfide erupted along the coast of Namibia in mid-March 2010. Pale-hued waters along the shore hinted at gaseous rumblings as the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite passed overhead and captured this true-color image on March 13, 2010. Although ocean water appears navy blue farther from shore, water along the coast ranges in color from peacock green to off-white. Ocean water wells up in this area along the continental shelf.
The milky surface waters that coincide with gaseous eruptions along Namabia’s coast have a low oxygen content. As reported in a 2009 study, the frequent hydrogen sulfide emissions in this area result form a combination of factors: ocean-current delivery of oxygen-poor water from the north, oxygen-depleting demands of biological and chemical processes in the local water column, and carbon-rich organic sediments under the water column.
Ugh. Theoretically, this was very common during the Permian Extinction. It would be interesting to know how often this happens in our current well mixed oceans.