Surprise! Earth's core has a core

[Panich52]

Surprise!  Earth's core has a core

Researchers have found that the Earth’s inner core has an inner core of its own, smaller than the moon.  It might hold the key to how our planet evolved.

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University of Illinois professor of geology Xiaodong Song and visiting postdoctoral researcher Tao Wang conducted the research, who results are available online http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2354.html in the journal Nature Geoscience.

Researchers use seismic waves from earthquakes to scan below the planet’s surface, much like doctors use ultrasound to see inside patients. The team used a technology that gathers data not from the initial shock of an earthquake, but from the waves that resonate in the earthquake’s aftermath. The earthquake is like a hammer striking a bell; much like a listener hears the clear tone that resonates after the bell strike, seismic sensors collect a coherent signal in the earthquake’s coda. Song said:

It turns out the coherent signal enhanced by the technology is clearer than the ring itself.

The basic idea of the method has been around for a while, and people have used it for other kinds of studies near the surface. But we are looking all the way through the center of the Earth.

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More:
http://earthsky.org/earth/the-surprising-core-within-earths-core?utm_source=EarthSky+News&utm_campaign=4361fc475b-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-4361fc475b-393525109

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[shenmue]

1. Does it have gooey chocolate?

[sakabatou]

2. Or a toy?

[shenmue]

3. Yeah!

A toy surprise!

[AgingAmerican]

6. More likely a cherry

nt

[Hissyspit]

5. Creamy filling.

Last edited Fri Feb 13, 2015, 06:01 AM - Edit history (1)

[Spitfire of ATJ]

7. No, it's the pits.

[Hekate]

4. Always fascinating stuff. Thanks!

[jakeXT]

8. So the mantle was once called outer core ?

http://en.m.wikipedia.org/wiki/Inge_Lehmann

[eppur_se_muova]

9. Keep looking ...

[Nitram]

10. I hate to be a buzz kill, but this is very old news.

The Earth's inner core was first hypothesized in 1936 by the Danish seismologist Inge Lehmann, based on analysis of seismic waves produced by an earthquake in New Zealand. Her hypothesis was confirmed in 1970 when more sensitive seismographs detected waves deflecting off this solid core.

http://www.amnh.org/education/resources/rfl/web/essaybooks/earth/p_lehmann.html

[Yo_Mama]

11. Thank you! I was just wondering if senility had struck, because

the "new" diagram looked the old diagram I remembered.

Thank you again.

[F4lconF16]

12. The part of interest is not that there is an inner core, like Lehmann discovered.

It's that the inner core has yet another inner core, leading to a total of five layers: crust, mantle, outer, outer-inner, inner-inner. This is instead of the old model where there was an inner core, but only one.