Posted on 10/17/2014 11:40:09 AM PDT by JimSEA
My reservation as to AGW are supported by the extreme conditions preceding mass extinctions and the historically higher CO2 levels experienced for most of earths history. One super volcano eruption could change everything for earth climates. Climates constantly change both in regional changes and worldwide variations. Geologic history is full of such variations. Look at the climatic variations that have been shown to affect human evolution.
The volcanic activity they talk about at the end of the Cretaceous are not single volcanos like St Helens, Krakatoa,
or even Yellowstone size eruptions. They are talking about the outpouring of the Deccan Traps in Western India. These flood basalts covered 193000 square miles to a depth of 5660 feet or about 123000 cubic miles of basalt lava. The largest outpouring lasted about 30,000 years. The same is true at the end of the Permian. The Siberia Traps eruptions lasted less than 1 million years but poured 720000 cubic miles of lava onto Northern Siberia.
Excellent point. One theory I had was that the Yucatan meteor shocked the Deccan area so severely that it cracked and oozed for thousands of years. Then I read about the theory by an Indian scientist that there was a huge strike off the coast of Mumbai. I think he called it the Shiva Crater and his name may be Sattargee or something like that.
I know that there are at least strikes associated with the Chesapeake Meteor about 34MYA, there is also the Toms River crater and Popogai in Russia.
Geologists are still debating the provenance of what may be an impact crater (Shiva) off the Indian coast. What is there would indicate an impact considerably larger than the Chicxulub. It appears to be roughly the same age as the Chicxulub impact and the Deccan Traps. I agree with the idea that the single impact in Mexico was not enough by itself to cause the extinction event. The Mexican impact, the Deccan Traps volcanism and the possibility of the Shiva impact all occurring close in age would damage the environment enough to finish off the already weakening dinosaur line.
Note: this topic is from 10/17/2014 . Adding to the list, not pinging.
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