Tag: Mantle

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Marble by petro c. k.

big blue marble
another turn
for the steelie

by petro c. k.

It shocked people earlier this year when news circulated that scientists calculated that the earth’s inner core is reversing its rotation in relation to the earth’s rotation of the crust. Don’t worry, this is fine. The solid metal core inside the earth spins cushioned by the liquid molten magma layer, with calculations showing that the speed of its rotation is independent of the rotation of the outer core. New research suggests every 35 years or so the inner metal ball slows down, stops, then switches direction. This 70-year cycle may explain corresponding differences to the earth’s magnetic fields and the length of the days.

In the game of marbles, solid metal marbles are called “steelies” and based on the author’s childhood, larger ones are especially prized.

Further reading:

‘Earth’s inner core may be reversing its rotation’, 2023, Science News: https://www.sciencenews.org/article/earth-inner-core-reverse-rotation

‘Multidecadal variation of the Earth’s inner-core rotation’, 2023, Y. Yang & X. Song, Nature Geoscience: https://doi.org/10.1038/s41561-022-01112-z

Author bio:

petro c. k. is a temporal being living on a spinning rock in a vast universe who writes tiny haiku about infinitesimally small moments of time. You can catch up with petro on Twitter here: @petro_ck

Check out other sciku by petro c. k. here: ‘Saturn’s Moons’, ‘Young Star’, and ‘Giggling’.

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Suspended by Michele Rule

Metal formation
Buried deep inside the moon
Suspended mass

by Michele Rule

When I read about the discovery of a huge metal mass buried deep underground below the surface of the moon, I immediately jumped to the idea of a spaceship crash site. But reading more I learned about several possible causes, one being an asteroid crash and the other related to the magma solidification of the Moon’s surface. Both involved the suspension of a metal “structure” in a large mass, five times the size of the big island of Hawai’i.

Further reading:

‘Astronomers Discover ‘Deep Structure’ Under Moon’s Largest Crater’, Futurism: https://futurism.com/the-byte/deep-structure-mass-moon-crater

‘Deep Structure of the Lunar South Pole-Aitken Basin’, Geophysical Research Letters: https://doi.org/10.1029/2019GL082252

Author bio:

Michele Rule lives in Kelowna BC where she writes poems and stories with two dogs, two cats and a supportive partner. Her first book is “Around the World in 15 Haiku”. You can find more of her writing via Linktree and on Twitter @michelerule.

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Diamond Rain

Does Neptune ever
feel lonely, with a wall of
diamonds round it’s heart?

Diamonds might be precious but they’re composed of carbon, an element that’s common here on Earth and throughout the universe.

Under the right conditions (pressure and heat) carbon turns into diamonds. Marvin Ross predicted in 1981 that such conditions might be found in the mantels of the Solar System’s ice giants, Neptune and Uranus.

Recent research has supported this, with laser shock experiments on polystyrene performed by Kraus et al. (2017) replicating the conditions approximately 10,000km below the surfaces of Neptune and Uranus. Their experiments created nanodiamonds, supporting evidence that diamond precipitation occurs in the mantels of these planets.

Now further research has strengthened this evidence. The earlier studies used pure hyrdrocarbon systems (polystyrene is C8H8) but the interiors of Neptune and Uranus are more complex than that, consisting mainly of a dense fluid mixture of water (H2O), methane (CH4), and ammonia (NH3).

To understand diamond formation under more complex conditions similar to those found on Neptune and Uranus, Zhiyu et al. (2022) investigated diamond formation using polyethylene terephthalate (PET) plastics (C10H8O4). The researchers found that diamond formation is likely to be enhanced by the presence of oxygen, which in their research accelerated the splitting of the carbon and hydrogen.

Under the conditions found on Neptune and Uranus it’s likely that much larger diamonds would be formed, potentially millions of carats in weight. Over millennia these vast diamonds are predicted to sink slowly through the icy layers of the mantel before melting near the cores, creating an ever changing layer of diamonds around the cores of the planets.

The latest research may also explain another peculiarity about Neptune and Uranus: their unusual magnetic fields. Under the conditions that form diamonds in the mantel, the researchers also found evidence that superionic water might be created. Superionic water conducts electric current and is likely to impact the planets’ magnetic fields.

In addition to learning more about the Universe, there are practical implications for us on Earth resulting from the research too. Nanodiamonds have a range of important uses, including in medical sensors, non-invasive surgery, sustainable manufacturing, and quantum electronics. This latest research points the way towards a new way of fabricating nanodiamonds for such uses.

Further reading:

Ross, M. (1981) The ice layer in Uranus and Neptune—diamonds in the sky? https://doi.org/10.1038%2F292435a0

Kraus, D. et al. (2017) Formation of diamonds in laser-compressed hydrocarbons at planetary interior conditions https://doi.org/10.1038/s41550-017-0219-9

Zhiyu, H.E. et al. (2022) Diamond formation kinetics in shock-compressed C─H─O samples recorded by small-angle x-ray scattering and x-ray diffraction https://doi.org/10.1126/sciadv.abo0617

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Mars

If you say water

then we say volcanism,

else Mars is too cold.

Recent observations of Mars have suggested the presence of liquid water beneath the ice at the South Pole, prompting researchers to ask how water could exist in liquid state under Mars’ environmental conditions.

Research by Soria and Bramson (2019) suggests that the most likely theory to explain the presence of water would be an underground source of heat such as the formation of a magma chamber in the area within the past few hundred thousand years. The researchers also suggest the reverse is true – if there isn’t such a heat source then it’s unlikely that the earlier suggestions of liquid water are correct.

Original reseach: http://dx.doi.org/10.1029/2018GL080985

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What lurks beneath?

What lurks beneath the

‘Mountains of Madness’? Maybe

it’s a mantle plume?

 

Antarctica has numerous subsurface lakes and rivers under its glaciers. Over 30 years ago it was hypothesised that there might be a mantle plume under West Antarctica which might be in part responsible for these subglacial water bodies.

Now there is increased evidence that such a mantle plume might actually exist: Seroussi et al (2017) wrote a three-dimensional ice flow model to understand how much geothermal heat would be needed to create the conditions observed at Marie Byrd Land in West Antarctica. They then compared this model with observations collected by a Nasa satellite. Their results lend support to the theory that there may indeed be a mantle plume under Antarctica.

Original research: https://doi.org/10.1002/2017JB014423