Sea Floor Spreading Greenhouse World
Introduction of isotopically light carbon into the ocean atmosphere system accompanied by global warming of 5 8 c across a range of latitudes took place over a few thousand years.
Sea floor spreading greenhouse world. During this period submarine volcanic carbon dioxide emissions were released high enough to cause atmospheric co 2 concentrations in excess of 1000ppm. The survey data was used to create three dimensional relief maps of the ocean floor and by 1953 american oceanic cartographer marie tharp had created the first of several maps that revealed the presence of an underwater mountain range. This theory focuses the control of co2 levels on plate tectonic processes. Evidence for rapid climate change in the mesozoic palaeogene greenhouse world.
The same greenhouse gas emissions that are causing the planet s climate to change are also causing the seafloor to dissolve. During plate tectonics carbon is cycled endlessly between the earth s. The cretaceous climatic optimum. Oae but the early aptian and cenomanian turonian oaes show the reverse effect implying that increased rates of sea floor spreading and hydrothermal activity dominated over continental weathering in governing sea water chemistry.
During plate tectonics carbon is cycled endlessly between the earth s. At times of enhanced tectonic activity and sea floor spreading elevated levels of greenhouse gas emissions may initiate or augment a greenhouse world. The cretaceous greenhouse world refers to a part of geological history that lasted from about 110 to 90 million years ago. Accepted in revised form.
Shortly after the conclusion of world war ii sonar equipped vessels crisscrossed the oceans collecting ocean depth profiles of the seafloor beneath them. The best documented example of rapid climate change that characterized the so called greenhouse world took place at the time of the palaeocene eocene boundary. The seafloor spreading theory is one hypothesis introduced to suggest a mechanism of controlled co2 levels in the atmosphere causing the observed variations between warm co2 rich greenhouse intervals and cold co2 depleted global cooling intervals. Kasting nasa ames research center ms 245 3 moffett field ca 94035 and steven m.
Richardson department of earth sciences iowa state university ames iowa 50011 received april 10 1985. This theory focuses the control of co2 levels on plate tectonic processes. Caldeira k rampino m r 1991 this then caused rapid sea floor spreading and the break up of continents. And new research has found the ocean bottom is melting away faster in.
00 seafloor hydrothermal activity and spreading rates. The eocene carbon dioxide greenhouse revisited james f. For more than 50 ma the net effect of all the factors fed on each other to encourage and sustain a global fall in temperature.