Effect of Oil Extraction on Earths wobble

amen

My daughters primary class were talking about the earths wobble and she came home and asked me if the mining/extracting of oil affected the earths wobble.

So we did a little experiment with a spinning top and adding weights and they had a dramatic effect on the tops rotation but I'm not sure what impact the removal of a mass from inside the earth would have on its wobble.

Also discussed rotation time.

The sad thing is I have a degree in physics ( 17 years since graduation) but I can't really remember any of this stuff.

Anyone have a formula or care to point me in the right direction.

Jumpy

I would say its the equivalent of adding a tiny speck of dust to the spinning top.

Sid_Justice

At a uneducated guess would the mass of oil and other natural resources extracted long with the forces acting to do so not be negligible compared to the massive mass of the Earth overall, thus having little or no effect on wobble?

http://www.space.com/11115-japan-earthquake-shortened-earth-days.html

Norwayviking

amen wrote: »

My daughters primary class were talking about the earths wobble and she came home and asked me if the mining/extracting of oil affected the earths wobble.

So we did a little experiment with a spinning top and adding weights and they had a dramatic effect on the tops rotation but I'm not sure what impact the removal of a mass from inside the earth would have on its wobble.

Also discussed rotation time.

The sad thing is I have a degree in physics ( 17 years since graduation) but I can't really remember any of this stuff.

Anyone have a formula or care to point me in the right direction.

I dont think the extraction of oil would have much impact on it,since they these days are pumping seawater into the wells to pressurize the wells to get up the last bit of oil.

http://en.wikipedia.org/wiki/Water_injection_(oil_production)

enda1

I may be wrong, but I believe that the wells are filled with water when the oil is extracted?

ray giraffe

All past and future oil production is roughly 2 x 10^14 kg.

The earth has a mass of 6 x 10^24 kg.

So any possible effect on rotation is at most 1 part in 30 billion, probably far less.

Nothing to worry about I'd say. Similar magnitude effects on rotation are already produced by large earthquakes.

E.g. The 2004 Indian Ocean Earthquake shortened the day by 1 part in 30 billion.

Even larger (but gradual) effects on day length occur naturally due to the gravitational pull of the moon on the earth.

There is also a natural wobble of the earth in space which is much larger than anything caused by oil extraction or earthquakes. http://en.wikipedia.org/wiki/Chandler_wobble

In summary, you'd do better to worry about the link between burning oil and climate change.

amen

thanks for all the replies. Not worried at all.
More that I couldn't answer my daughter.

SOL

surely there will be an effect on the earths rotation from the fact that you are taking a mass and moving it from beneath the earths crust to being distributed throughout the atmosphere... so while an earthquake moves large masses but only a small ammount, we are taking it and pushing it possibly miles further out from the centre of rotation?

Ellis Dee

SOL wrote: »

surely there will be an effect on the earths rotation from the fact that you are taking a mass and moving it from beneath the earths crust to being distributed throughout the atmosphere... so while an earthquake moves large masses but only a small ammount, we are taking it and pushing it possibly miles further out from the centre of rotation?

The mass of the oil involved is so vanishingly tiny compared with the mass of the planet that it's hard to imagine it having any effect ...

... but then the words "butterfly effect" keep nagging at my mind.

http://en.wikipedia.org/wiki/Butterfly_effect