Global Warming Shifts the Earth's Poles

ananyo writes "Global warming is changing the location of Earth's geographic poles, according to a study published this week. Researchers at the University of Texas, Austin, report that increased melting of the Greenland ice sheet — and to a lesser degree, ice loss in other parts of the globe — helped to shift the North Pole several centimeters east each year since 2005. From 1982 to 2005, the pole drifted southeast towards northern Labrador, Canada, at a rate of about 2 milliarcseconds — or roughly 6 centimetres — per year. But in 2005, the pole changed course and began galloping east towards Greenland at a rate of more than 7 milliarcseconds per year (abstract). The results suggest that tracking polar shifts can serve as a check on current estimates of ice loss. Scientists can locate the north and south poles to within 0.03 milliarcseconds by using Global Positioning System measurements to determine the angle of Earth's spin. When mass is lost in one part of a spinning sphere, its spin axis will tilt directly towards the position of the loss — exactly as the team observed for Greenland."

Comments

Three Gorges Dam

[ShanghaiBill]

Part of this shift could be caused by filling the reservoir behind the Three Gorges Dam, since that is on the opposite side of the world from Greenland. But that would only explain part of it, since the reservoir holds about 40km^3 and Greenland is losing about 240km^3 per year.

Re:Three Gorges Dam

[Aardpig]

I welcome our new Asian Overlords and their Moment of Inertia.

Re:Three Gorges Dam

[JMJimmy]

Something about this article just feels wrong. http://en.wikipedia.org/wiki/True_polar_wander feels more right - just sits better in my gut. ;)

Re:Three Gorges Dam

[bmo]

A nautical mile isn't an "imperial unit"

It's a nautical unit. It's actually Babylonian. It's useful for measuring the Earth because it's "close enough" to a minute of arc.

If Gunther had changed his surveyor's chain to 1/100 of a nautical mile in 1620, (instead of 1/80'th statute mile)^1 we wouldn't be talking about the Meter at all, as it would have been useless.

--
BMO

1. A nautical mile is 92.06 chains. An adjustment of the chain to 100 per NM wouldn't have been a big difference, and made things even easier for surveyors and engineers.

Shifting Poles

[Anonymous Coward]

There was this guy called Adolph that shifted the Poles too

Re:The opposite might also be true

[Anonymous Coward]

I agree. Global warming may or may not be caused by humans. Perhaps in part. Regardless, we should focus on cutting pollution even if global warming is not man-made.

Re:Surface Drift Question

[EmagGeek]

The crust does drift, and because the crust does not have uniform thickness, crustal drift changes the center of gravity and angular momentum of the Earth, and also shifts the poles.

Also, if there is a major earthquake that sinks a large portion of crust any appreciable amount, the rate of rotation AND center of gravity change, and poles shift some more.

There are many many vectors of change for the position of the poles. To assume that all of the observed drift is due to the change in mass of a single ice sheet is ludicrous. But, we're talking about the chicken little global warming narrative here, so anything goes.

Re:The opposite might also be true

[JasterBobaMereel]

Changes like this have happened time and time again ... and the world will continue and life will continue

The problem is it might not be habitable by 7billion humans ... this *will* affect you