How well did the moon fair? Are they getting lunar warming too?
Did I mention the billions of tonnes of sulfur used to condition farmland from over fertilizing and irrigation?
Did I mention the billions of tonnes of sulfur used to condition farmland from over fertilizing and irrigation?
Earth catastrophies are numerous and extremlely diverse.Massive release of hydrogen sulfide to the surface ocean and atmosphere during intervals of oceanic anoxia
Lee R. Kump*,1, Alexander Pavlov*,2 and Michael A. Arthur*,3
[SIZE=-1]1 Department of Geosciences, Pennsylvania State University, 535 Deike Building, University Park, Pennsylvania 16802, USA
2 Center for Astrobiology, Laboratory for Atmospheric and Space Physics, University of Colorado, C.B. 392, Boulder, Colorado 80309-0392, USA
3 Department of Geosciences, Pennsylvania State University, 538 Deike Building, University Park, Pennsylvania 16802, USA [/SIZE]Simple calculations show that if deep-water H2S concentrations increased beyond a critical threshold during oceanic anoxic intervals of Earth history, the chemocline separating sulfidic deep waters from oxygenated surface waters could have risen abruptly to the ocean surface (a chemocline upward excursion). Atmospheric photochemical modeling indicates that resulting fluxes of H2S to the atmosphere (>2000 times the small modern flux from volcanoes) would likely have led to toxic levels of H2S in the atmosphere. Moreover, the ozone shield would have been destroyed, and methane levels would have risen to >100 ppm. We thus propose (1) chemocline upward excursion as a kill mechanism during the end-Permian, Late Devonian, and Cenomanian–Turonian extinctions, and (2) persistently high atmospheric H2S levels as a factor that impeded evolution of eukaryotic life on land during the Proterozoic.