Ancient Cataclysm Rearranged Pacific Map, Study Says

Julian Ryall
for National Geographic News
October 24, 2007

A cataclysm 50 million years ago changed the face of the planet from the Hawaiian Islands to Antarctica, according to new research.

The collapse of an underwater mountain range in the Pacific Ocean turned Australia into a warm and sunny continent instead of a snowbound wasteland and created some of the islands that dot the South Pacific today.

"We have found that the destruction of an entire mid-ocean ridge, known as the Izanagi Ridge, initiated a chain reaction of geological events," said Joanne Whittaker, a doctoral student at the University of Sydney's School of Geosciences who led the research.

Using geophysical data gathered by scientists from Australia and Russia, the team confirmed that the ridge plunged underneath a plate of Earth's crust that stretches between the Korean Peninsula and Japan.

The Japanese landmass then acted as a vast plug in the crack between the plates, changing their movement and rearranging the geography of the Pacific, the team found.

This eventually led to the emergence of dozens of small volcanic islands that dot the southwest Pacific, including Tonga and the island chains that run north and east from Papua New Guinea (see map).

"The cause of [this] major change in the motion of the Pacific plate has long puzzled scientists," Whittaker said.

The team also deduced that the event changed the movement of the Australian continent, causing it to move due north at 2.75 inches (7 centimeters) a year.

"Australia would have been located much further south and would have had a climate more similar to Scandinavia or Alaska" were it not for this event, Whittaker said.

"Only the very northern parts of the continent would have been warm."

"Controversial" Theory

At the time of the event, Antarctica and Australia were part of the same southern landmass.

Continued on Next Page >>


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