Researchers discover giant asteroid impact crater in Antarctica

Saturday, June 3, 2006 

GRACE-measured gravity fluctuations beneath East Antarctica . Denser regions appear more red; the location of the Wilkes Land crater is circled (above center). Image courtesy of Ohio State University.

Researchers have found a giant asteroid impact crater under the Wilkes Land ice sheet of Antarctica and it may have been responsible for creating the conditions in which dinosaurs evolved, but may also have been the cause of a mass extinction.

"This Wilkes Land impact is much bigger than the impact that killed the dinosaurs, and probably would have caused catastrophic damage at the time," said Ohio State University Professor of geological sciences, Ralph von Fres.

"All the environmental changes that would have resulted from the impact would have created a highly caustic environment that was really hard to endure. So it makes sense that a lot of life went extinct at that time," added von Fres.

The crater is over 300 miles wide and was made about 250 million years ago by an asteroid nearly 30 miles wide. Researchers say that it may have caused an Earth-wide Extinction Level Event (ELE), but also may have created the conditions under which dinosaurs evolved. The species that benefited include the archosaurs, the immediate ancestors of the dinosaurs.

It is thought that nearly 96% of Earth's ocean life and at least 70% of animals on land were made extinct. The impact itself may also have caused the supercontinent Gondwana to break, ultimately forming Australia.

Sources

• Lewis Smith. "Huge meteor strike that 'gave birth to the dinosaur'" — Times Online, June 2, 2006

• Pam Frost Gorder. "Big Bang In Antarctica -- Killer Crater Found Under Ice" — Ohio State University, June 1, 2006

• Frank Walker. "How Australia was born" — The Sydney Morning Herald, June 4, 2006