by Keith_McClary » Sun 23 Jan 2011, 03:28:58
$this->bbcode_second_pass_quote('SeaGypsy', '')$this->bbcode_second_pass_quote('scas', 'I') know i've said it before, but redistribution of large masses of polar and glacial ice are sure to affect the Earth's wobble...
Greenland's ice mass has to be significant enough to change the axis. I guess how suddenly this melts will affect the wobble. Has anyone done the maths on where the axis is with Greenland's ice sheet melted?
I'm sure someone has - there are many bright young Ph.D. students looking for an earth shaking topic. Try your favorite search engine.
EDIT:According to:
Sea Level Rise Could Hit North America HardestMitrovica also considered the wobble.
$this->bbcode_second_pass_quote('', 'T')he scientists’ model took into account the West Antarctic ice sheet’s gravitational pull on nearby ocean water
...
Second, researchers found that if the weight of the ice disappears, the tectonic plate that it has kept buried beneath it will rise, forcing water to flow into other areas.
...
Finally, the melting ice sheet also would change the way the earth wobbles as it spins, according to the study. This would redistribute the ocean’s depth, transferring seawater from areas in the southern Atlantic and Pacific oceans to the southern Indian Ocean and areas around North America.
“When you remove the mass of the ice, the earth will change its axis,” says Holland of New York University. “Big chunks of water will move to the equator” from Antarctica, he adds.
...
The results of the study startled even its authors. “I knew that the gravitational effect on meltwater would be important, but I was very surprised the contributions from the other two effects were
just as large,” says Mitrovica.
Effects due to the wobble are "just as large" as a small correction to previous estimates of sea level rise in some locations.
This would be a pretty small effect. I wonder if astronomers can measure the changing wobble yet?
The full text of Science Magazine papers over 1 year old are accessible with free registration:
The Sea-Level Fingerprint of West Antarctic Collapse