The Earth is Getting Fatter

murk1e writes "The BBC News service has an article which reveals that the Earth is getting fatter. It is well known that the Earth is slightly wider at the equator than at the poles, it is less well known that for years, the Earth has been becoming more spherical. Now it appears that the trend has reversed, and the Earth is getting more obese (in the sense of shape change rather than changing mass). Perhaps the Earth should sue?"

Comments

Re:an effect of modern "civilization?"

[tsa]

If you look at films of liquid 'bubbles' in spaceships you'll see that they make the same movements, only faster and more extreme. I think it's just a natural phenomenon

Probably just a normal oscillation

[Jerf]

This is probably just a normal oscillation the Earth undergoes, driven by the impetus of the various gravitational influences it experiences over time. If we waited around long enough, it would probably start going back.

In fact, just thinking about it, it's virtually inconceivable that it wouldn't oscillate this way. Consider the Earth as a giant drop of water cruising through space. (Note that on a plantary scale, everything is liquid, which is why the surface is smooth. If the Earth were the size of a cue ball, it would be the smoothest cue ball ever made. This is also why blowing up a planet and seeing huge chunks fly away is stupid; it's basically a liquid, it should 'blow up' like one.) Of course it oscillates, what with Saturn and Jupiter and innumerable other influences constantly 'twanging' it.

The only real question is what the period is.

Note that it is utterly inconceivable that humanity has had any significant effect on this process simply by moving mass around. Do a compution on the total mass we've ever moved around, at all. Be generous; go ahead and assume 2002-level industrial output for 10,000 years of human history, which will be an overestimate by about a factor of 5,000. Now divide by the mass of the Earth. Then remember to use your brain when thinking about human effects in the future. (Some things we can and do affect negatively. There are other things we could literally not hope to effect in a million years. Moving a significant fraction of the planet is one of those. Recall the planet is a huge sphere of which "the surface" is itself only a tiny, tiny fraction...)

link to original NASA press release about this

[dolsen]

to repeat... the following is a link to the original NASA press release. It also includes two rather pointless images that highlight the direction of the "bulge" pre-1997 and post-1997.

• Satellites Reveal a Mystery of Large Change in Earth's Gravity
  Satellite data since 1998 indicates the bulge in the Earth's gravity field at the equator is growing, and scientists think that the ocean may hold the answer to the mystery of how the changes in the trend of Earth's gravity are occurring.

if you like the globe in the images there's a better one on the same web site called the Blue Marble

and don't forget to check out the Natural Hazards