Danish Research Center To Explore Mysteries of Earth's Interior

An anonymous reader writes "The DanSeis Centre at the University of Copenhagen has just received a grant of more than €3 million from the Danish Ministry of Science, Innovation and Higher Education to investigate and tackle one of geoscience's great mysteries: do mantle plumes, hypothetically buoyant regions of heated mantle material rising towards the earth's surface, actually exist?"

Comments

Foregone conclusion....

[vjoel]

...it's a plume filled danish.

Re:Foregone conclusion....

[philip.paradis]

If the planet is consuming too many plum filled danishes, I can certainly understand hot bubbles of materials rising up.

Oh, sorry, you said "plume," not "plum." Never mind. Also, for anyone who thought of hot grits and/or Natalie Portman while reading the above, you've got issues bro.

Great News

[guttentag]

I will be watching this closely, as I have often wondered what on Earth is at the center of a Danish.

What "new methods and instruments" ?

[Taco Cowboy]

In the article, it is stated that

"Using new methods and instruments, we can take geologic measurements much deeper within the Earth than before. Now, down to 500 and 1000 kilometers! Methods in current use, by the oil industry among others, provide information for areas down to between 6 and 10 kilometers," explains Professor Thybo.

If the multi-trillion-dollar oil industry can only make geologic measurements to a depth of 6 to 10 kilometers, what make you think a research program that cost 3 million euro can measure down to 500 or even 100 kilometers?

Just what kind of "new methods" and "instruments" are they going to deploy??

Re:What "new methods and instruments" ?

[Rakshasa-sensei]

Also they aren't out to drill for oil at 500-1000 km depths.

Re:What "new methods and instruments" ?

[hackertourist]

The oil industry won't spend money researching depths they can't drill to.

What about the discontinuity of gravity?

[UnknownSoldier]

Why is the force of gravity at the core zero?
http://en.wikipedia.org/wiki/File:Earth-G-force.png
http://en.wikipedia.org/wiki/File:Slice_earth.svg

And why the hell is there a Gutenberg discontinuity where gravity increases the closer you get, then drops down to zero?
i.e.
The Gutenberg Discontinuity, is the boundary, as detected by changes in seismic waves, between the Earth's lower mantle and the outer core about 1800 miles below the surface. It is also called the core-mantle boundary.
http://en.wikipedia.org/wiki/Mohorovi%C4%8Di%C4%87_discontinuity

Re:What about the discontinuity of gravity?

[jlar]

"Why is the force of gravity at the core zero?"

Because the integral of the forces acting on some mass at the center of the Earth is zero. Or to put it differently: You are being pulled by (approximately) equal forces in all directions.

Re:What about the discontinuity of gravity?

[rgbatduke]

Gravity does not increase once you are inside the Earth's surface unless perhaps you are moving down towards a large, cow-shaped lode of pure Uranium. Newtonian gravitation satisfies a Gauss Law (like electrostatic fields) and aside from minor perturbation due to the Earth being rotationally deformed and the tides, the field starts at zero at the origin/center and smoothly increases as one moves toward the surface in any direction, then smoothly decreases (like $latex 1/r^2$) once one is outside of it. Rotation (e.g. coriolis forces) alter the perceived local acceleration by a hair as a function of latitude. The slight equatorial bulge and compressibility of the core material keep the field from increasing ideally/linearly (as it would for a perfect sphere of uniform density). Finally, the Sun and the Moon create further local acceleration perturbations that are not strictly speaking variations in the Earth's field, but that result from the non-uniformity of the Sun and Moon's fields and the fact that the center of mass of the Earth has a different acceleration than points on its surface as it interacts with them both (the tides).

None of these things are even slightly mysterious. None of them are really particularly difficult to calculate, or at least estimate. "Interesting" discoveries from the systematic study of near-Earth and inner-Earth gravity are entirely possible, but one would ordinarily consider the discover of a fifth force, or a short range modulation of the gravitational force, to be "interesting" in this context. In order to make such a discovery, however, one has to know the mass distribution and compute the net relative acceleration one should be observing to very high precision, as one is basically looking for an anomaly, and small deviations from a not-too-well-known or even well-defined base quantity are the most difficult to detect, see the entire (somewhat humorous) debate about global warming for an example).

rgb

P.S. -- Off-topic general query: Wordpress lets one embed latex in comments, and it isn't even particularly focussed on technical subject matters. Is there an equally simple way to embed latex in /. comments? I'd put the ideal form of gravitation inside a sphere inline into this reply, except that nobody wants to read things like \vec{g} = -\frac{GMr}{R^3} \hat{r} or the derivation of same in latex unless they know latex well enough to read it as rendered...

Re:Onion and /.

[Anonymus]

Slashdot is basically the techie equivalent of Fox News. We don't really come here to get information, we come here to get entertained and enraged by things that fit our point of view.

Danish

[Plammox]

The horrible abominations you call Danish pastry over in the US, I wouldn't even feed to the pigs. I wouldn't mind my nationality being associated with a custard-filled fatty pastry, if only it was a delicious custard-filled fatty pastry. For heaven's sake, turn them into bio fuel or something, because they certainly aren't suitable for human consumption.

Same goes for your coffee, by the way. :-)