Wednesday, January 24, 2007

Permian Ocean Stagnated from Glacial Melt?

While I am working out the diagram for the Permian Extinction post that I promised, I realized that there might have been another mitigating circumstance that helped stagnate the Panthalassa, Neotethys and Tethys Oceans.

There has been some discussion as of late wrt to the Greenland glaciers and the North Atlantic current. The idea I seen bandied around is that if enough of the Greenland glacier were to melt, it will have changed the salinity in the top layers of the ocean that would lead to a shutdown of thermohaline circulation. The thought that occurred to me is that this might apply to the Permian.

Consider, during the Carboniferous there was extensive glaciation as Gondwanaland drifted south. This continued into the Permian for some time. If the extensive glaciers were still around up until the Siberian Traps began spewing out carbon dioxide, then the extensive warming might have melted enough of the glaciers, fast enough, to induce some severe stratification of the oceans. The lower layers would turn anoxic and a comfortable home for the hydrogen sulfide producing bacteria. As the oceans warmed, the oxygen levels would fall, and as the hydrogen sulfide passed into the upper layers, kill off more life and reduce the oxygen levels more. This would allow the bacteria to take up residence here too and make things all the worse.

Blend in the possibility of hurricanes on a massive scale - since you have very hot atmosphere, high humidity, and very warm surface ocean waters - and you have hydrogen sulfide being imported via rain inland.


It depends on when the end of glaciation took place and the Siberian Traps started. Something that's mildly testable.

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