Posted on 04/29/2002 9:52:58 AM PDT by cogitator
Though these aquamarine clouds in the waters off the coast of northern Namibia may look like algae blooms, they are in fact clouds of sulfur produced by anaerobic bacteria on the ocean’s floor. This image of the sulfur-filled water was taken on April 24, 2002, by the Sea-viewing Wide Field-of-View Sensor (SeaWiFS), flying aboard the Orbview-2 satellite.
The anaerobic bacteria (bacteria that can live without oxygen) feed upon algae carcasses that exist in abundance on the ocean’s floor off of Namibia. As the bacteria ingest the algae husks, they produce hydrogen sulfide, which slowly builds up in the sea-floor sediments. Eventually, the hydrogen sulfide reaches the point where the sediment can no longer contain it, and it bubbles forth. When this poisonous chemical reaches the surface, it combines with the oxygen in the upper layers of the ocean to create clouds of pure sulfur. The sulfur causes the Namibian coast to smell like rotten eggs, and the hydrogen sulfide will often kill fish and drive lobsters away.
There's a lot of interesting geology and geology-related phenomena in this image. The anoxic sediments that give rise to the sulfur precipitation in the water column fall under the "geology" heading. On the coast (and particularly in the higher-resolution image that is linked on the page above) you can see the Brandberg Mountains (a granitic pluton, I think). Also in the high-res image, at the top you can see some sediments from a river that manages to flow through one of the driest deserts on Earth, the Namibian coast.
Don't forget to check out the other images on the page today, including a high-altitude close-up of Mt. Everest that messes with your perspective.
I'll do a non-remote-sensing image next week, I promise. More action from Kilauea can be seen on this page:
Research into the Monterey Formation over the past 20 years, particularly by my colleague at the USGS, Caroline Isaacs, suggest that it is in part a bioclastic unit (highly diatomaceous, associated with upwelling events.
Thanks for the ping.
Very cool indeed. Thanks again for posting these.
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