How Gondwanaland got Australia to move out of the neighbourhood without being obvious

[sff_corgi_lj]

Gacked from electroweak, co-creator of A Miracle of Science:

From Space.com, BBC Science/Nature News, the Sydney Morning Herald and The Age

Big news from the American Geophysical Union Joint Assembly held in Baltimore this past May 23-26: A team of Ohio University, NASA, Russian and Korean scientists led by Prof. Ralph von Frese from OSU, who had been looking at differences in density that show up in gravity measurements taken with NASA's GRACE satellites noticed, beneath Antarctica's icy surface, a 321-kilometre-wide plug of mantle material — a mass concentration, or "mascon" in geological parlance — that had risen up into the Earth's crust. Cross-referencing against radar imagery, the team found a corresponding 500-kilometre-diameter circular ridge, also still buried beneath 1.6km of ice, which seemed to confirm their suspicions.

The mascon is located in Wilkes Land, East Antarctica; its coast faces Australia, which claims the area as far as the Antarctic Treaty allows such claims.

'...[the impact] could have begun the break-up of Gondwana supercontinent by creating the tectonic rift that pushed Australia northward," the team's leader Ralph von Frese said in a statement. "The rift cuts directly through the crater, so the impact may have helped the rift to form."

The size of the meteor itself has been compared to the city of Sydney; the resulting impact ridge to the size of Tasmania.

The impact is now thought to have started the Permian-Triassic extinction, which wiped out most life on land and in the oceans. Immediate effects would have included shock waves, firestorms, earthquakes, tsunami and vapourised materials contaminating the atmosphere. Secondary side effects from the damage, which punched completely through the earth's crust, would have been supervolcanism perpetuating the environmental changes for centuries.

False-colour radar image of the mascon, ridge and comparison to the Chicxulub crater of Yucatan
Interactive Flash animation of the breakup of Pangaea/Gondwanaland
GIF animation of breakup of Pangaea/Gondwanaland (wow, lookit India fly!)

Any errors in summation are mine, due to the fact that I'm still getting dressed, ack!