Earth's inner core has an inner core of its own

  • Thread starter Dotini
  • Start date
  • #1
Dotini
Gold Member
633
231
Thanks to a novel application of earthquake-reading technology, researchers have found that the Earth's inner core has an inner core of its own, which has surprising properties that could reveal information about our planet.

http://www.sciencedaily.com/releases/2015/02/150209113222.htm

The inner core, once thought to be a solid ball of iron, has some complex structural properties. The team found a distinct inner-inner core, about half the diameter of the whole inner core. The iron crystals in the outer layer of the inner core are aligned directionally, north-south. However, in the inner-inner core, the iron crystals point roughly east-west.

150209113222-large.jpg

A research team from the University of Illinois and colleagues in China found earth's inner core has an inner core of its own, with crystals aligned in a different direction.
Credit: Lachina Publishing Services

Journal Reference:

  1. Xiaodong Song et al. Equatorial anisotropy in the inner part of Earth’s inner core from autocorrelation of earthquake coda. Nature Geoscience, Feb 9, 2015
 
Last edited:

Answers and Replies

  • #2
phinds
Science Advisor
Insights Author
Gold Member
2021 Award
17,591
9,448
Nature seems to always have surprises in store for us. Just when we think we've got something nailed down reasonably well, the nails pop loose ... keeps things interesting. Thanks for posting that.
 
  • Like
Likes Dotini
  • #4
Bystander
Science Advisor
Homework Helper
Gold Member
5,331
1,414
The iron crystals in the outer layer of the inner core are aligned directionally, north-south. However, in the inner-inner core, the iron crystals point roughly east-west.
o_O :olduhh: What "in" earth does this mean?

Edit: We're going to add not just one, but two anisotropic allotropes to the iron phase diagram?
 
Last edited:
  • Like
Likes Dotini
  • #5
769
15
Hmmm, an interesting use of the increasingly popular "seismic interferometry" technique..
The "inner inner core" is nothing new, it's been around for over 10 years now. So most of the media hype is just that, hype.
Previous work has suggested that this inner inner core can be explained away by heterogeneity in the outer inner core, and this work really doesn't seem to lay that concern to rest (to me at least). I suspect this paper is not the last word.
 
  • #6
Dotini
Gold Member
633
231
A interesting and unique new image of our planet's mantle based on earthquake vibrations.

http://www.newscientist.com/article...-of-the-inside-of-the-earth.html#.VQgptkvoaX3
dn27170-1_1200.jpg
(Image: Ebru Bozdağ, University of Nice Sophia Antipolis, and David Pugmire, Oak Ridge National Laboratory)

Eavesdropping on earthquakes is painting a picture of the Earth's interior that looks like the swirling colours inside a marble. This view beneath the Pacific Ocean, based on simulations run by Jeroen Tromp from Princeton University and his team, uses different colours to represent the speed of seismic tremors, giving an insight into the planet's inner structure.
 

Related Threads on Earth's inner core has an inner core of its own

Replies
2
Views
1K
  • Last Post
Replies
6
Views
5K
  • Last Post
Replies
7
Views
4K
  • Last Post
Replies
3
Views
10K
  • Last Post
3
Replies
83
Views
24K
  • Last Post
Replies
23
Views
6K
  • Last Post
Replies
1
Views
1K
Replies
13
Views
6K
  • Last Post
Replies
5
Views
3K
Top