This page is a copy of my Geocities page initially posted at the following link ...
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Modification and Enhancements to the initial version of the hypothesis:

Plate tectonics and the Global climate

Date: 11th March, 2001.

The only major change from the initial version is the addition of Milankovitch cycles for the initiation of ice ages. In the whole history of the Earth, severity of the ice ages and global warming occurring with the changes in seafloor spreading. Because of this analogy I didn't give much attention to the solar radiation in my initial hypothesis.

Severe ice ages occur with the Supercontinent formation - collision of multiple continents.
Medium scale ice ages occur with the collision of two continents.
Small scale ice ages occur with the low incoming solar radiation.

Severe global warming occurs with the breakup of Supercontinent.
Medium scale global warming occur with the break in the crust, either oceanic or continental.
Small scale global warming occur with the high incoming solar radiation.

Because of these observations I have attributed the cause for the severe changes in the climate to the changes in the seafloor spreading and said that seafloor spreading supplies more heat than the Sun even though I was not fully satisfied with that statement. I was of the opinion that seafloor spreading and the variation in the solar radiation effects the climate independent of each other. I have modified my hypothesis by including the Milankovitch cycles and also changed my views about the continental collision and the notion of ‘liquid mantle’.

Date: 18th August, 2002.

I wrote the sequence of global ice ages starting with the recent one as 200, 625, 1050, 1500, 1950, 2400, 2825 million years ago (Ma) with a frequency of 425 million years. I was not only calculated the sequence wrong but also assumed that the recent global ice age occured around 200 Ma. The correct sequence starting from the recent would be 200, 625, 1050, 1475, 1900, 2325 and 2750 Ma.

I strongly believed that the formation of Pangaea should result in a global ice age. And also having an opinion that the breakup of this Supercontinent caused a major mass extinction. Most of the resources I encountered with were refering to the period of the Pangaea as 200 Ma. On these grounds I have calculated the sequence and compared the Permian extinction with the events of the Supercontinental breakup at 200 Ma.

With further exploration I found that the Permian extinction occured around 250 Ma. Continental collision and global glaction were also preceded the mass extinction. This event as a basis, the sequence of glaciations and the supercontinents was revised in the updated hypothesis as 250, 675, 1100, 1525, 1950, 2375 and 2800 Ma.

Karunakar Marasakatla
Last modified: 18th August, 2002.

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