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.
Commercially important fish species have hatching grounds along the Namibian coast, and hydrogen sulfide eruptions can often kill large numbers of fish. In addition, the gas eruptions send a noxious rotten-egg smell inland. These events bring some benefits, however. Sea birds eat the fish carcasses, and humans can make meals of lobsters fleeing onshore to escape the oxygen-deprived waters.
Inland, this MODIS image shows the rippling sand dunes of the Namib Desert, which stretches for hundreds of kilometers along the southern African coast.
Acquired March 13, 2010, this true-color image shows pale-hued surface waters along the coat of Namibia, ranging in color from peacock green to off-white. Inland, the image captures the rippling sand dunes of the Namib Desert.
People living along Namibia’s desert coast have long been familiar with the rotten-egg smell that periodically emanates from the Atlantic Ocean. With an economy that is largely based on fishing, the locals are also used to seeing millions of fish die whenever the unpleasant scent fills the air. The smell and the fish die-off are caused by hydrogen sulfide erupting from decaying plants on the sea floor. On May 12, 2004, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image of a hydrogen sulfide eruption in progress.