Tuesday, February 10, 2009

Did volcanoes kill the dinosaurs?

Since 1980, scientists have believed a meteorite impact in the Yucatan caused a mass extinction of species, including the dinosaurs. But geologist Gerta Keller of Princeton disagrees.
Gerta Keller: This impact didn’t cause any species extinctions.
According to 20 years of research by Keller and her team, this impact happened 300 thousand years after the dinosaurs disappeared. Keller believes that — instead of a space rock — volcanoes might have killed the dinosaurs.
Gerta Keller: Now we find that the other catastrophe, which is Deccan Volcanism, which has not had much attention paid to it, may be the real culprit.
She’s talking about volcanic eruptions on India’s Deccan plateau between 63 and 67 million years ago. The volcanoes spewed huge amounts of sulfur dioxide into the air. Keller’s team studied geologic core samples from the area. With each subsequent volcanic flow, Keller said, less evidence of life appears within the cores.

Program #5715 of the Earth & Sky Radio Series with hosts Deborah Byrd, Joel Block,Lindsay Patterson and Jorge Salazar.