Climate Change Is Making the Earth Wobble

[WhiteTara]

http://news.yahoo.com/climate-change-making-earth-wobble-200121952.html

As pollution from burning fossil fuels continues to heat the atmosphere, the world’s glaciers are melting at an accelerating rate. Scientists widely agree that this meltwater has been a major factor in raising global sea levels about seven inches over the 20th century.

The movement of all that water is affecting the Earth’s rotation, according to a study published Friday in the journal Science.

“If you are melting glaciers from high latitudes—in Alaska, Greenland, or Iceland—you move mass away from the pole, toward the equator, which slows the Earth down,” said Jerry Mitrovica, the study’s lead author and a Harvard geophysicist who specializes in studying sea level change. “The change in the distribution of the mass from the poles to lower latitudes also causes the rotation to wobble slightly, because it’s being redistributed unequally.”

That change in rotation added a microsecond to the course of a day over the 20th century.


We can only hope COP21 has some effect on the warming planet,

[shraby]

1. If I recall correctly, the earth has always had a wobble and from time to

time we have also had to add fractions of seconds to a day.
Tell me what has changed?

[comradebillyboy]

2. Earth's axis wobbles on a 26,000 year cycle

For more than a century scientists have known that Earth’s ice ages are caused by the wobbling of the planet’s orbit, which changes its orientation to the Sun and affects the amount of sunlight reaching higher latitudes, particularly the polar regions. - See more at: http://www.astrobio.net/topic/solar-system/earth/ice-ages-and-earths-wobble/#sthash.Z5kywoI9.dpuf

[Igel]

3. That's precession.

"Wobble" is ambiguous, and while it's used for precession what's under discussion here this is more of a small change due to a redistribution of mass, not to an axis at what--25 1/2 degrees is it? We've always had both kinds of wobble.

That's what you get with a slightly squishy oblate spheroid that's rotating and subject to external gravitational forces, esp. one that has a thin layer of sloshy stuff on it.

Sea levels have risen far more than 7 inches in the last 13k years or so. The earthquake in Nepal shifted the Earth's mass slightly. Both caused changes in mass distribution and both affected the Earth's rotation.