The #core of the #Earth spins around a slightly different axis compared to the #mantle. In this animation we start in a space frame and switch gradually to the frame spinning with the mantle. In that frame the core appears to wobble. The mantle precesses and the core, being fluid, lags a bit. 🧪 🔭 - ThreadSky

ututuy.org • 95 days ago

The #core of the #Earth spins around a slightly different axis compared to the #mantle. In this animation we start in a space frame and switch gradually to the frame spinning with the mantle. In that frame the core appears to wobble. The mantle precesses and the core, being fluid, lags a bit. 🧪 🔭

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gantamk.bsky.social•94 days ago

Fascinating. Wow 😮

memkiii.bsky.social•94 days ago

How do we know how much & at what rate? Is it purely the magnetic field shifting? or some other method?

ladyvictorias.bsky.social•94 days ago

Mesmerizing 😃

drstrawpants.wobbly.earth•94 days ago

That's a nice way to visualize this. Is the amplitude of the rotation axis (mantle frame versus crust) really to scale??? Or is it enlarged for illustrative purposes? Over what timespan does this visualization run?

drstrawpants.wobbly.earth•94 days ago

I'm slightly confused because for geodesy folks "slightly different axis" usually means something in the order of 10-100 mill-arcseconds.

ututuy.org•94 days ago

yes, variations of the Earth's orientation over comparatively short periods (decadal or smaller) are measured in milliarcseconds. The mismatch caused by secular precession (super long period of 26000 years) is actually close to 3.5 arcseconds. This one is not measured but inferred.

ututuy.org•94 days ago

That’s right! The angle is enlarged a lot to ease visualization. The actual angle is only a tiny fraction of a degree. Time span is about 12-15 days. The wobbly motion of the core at the end has a diurnal period.

drstrawpants.wobbly.earth•94 days ago

thanks, that explains it

ninedot.bsky.social•93 days ago

Good thing we never had to drill down to it to detonate a nuke, like in that parallel universe documentary.

fairyqueen13579.bsky.social•84 days ago

Thank you so very much for liking my posts and yours too bless you and hope you have a lovely day today blessed be ❤️...

sevenrasmussen.com•95 days ago

oh hell yeah

willormay.bsky.social•93 days ago

Thanks Santiago, you’ve given me a lot to think about

fatinamalik.bsky.social•94 days ago

This animation is 🔥🔥

aceja.bsky.social•93 days ago

This is why magnetic north is not at the north pole and moves over the years.

sagnikprusty.bsky.social•94 days ago

Intresting!

rebeccabingham.bsky.social•89 days ago

I’m curious how (if?) these phenomena correlate with pole-shifting. https://www.npr.org/2021/02/18/969063568/ancient-trees-show-when-the-earths-magnetic-field-last-flipped-out

ututuy.org•89 days ago

The flow induced by precession is not directly related to the wandering of the magnetic field, but other kinds of flows in the core are! this is something the scientists are still trying to understand them properly.

ututuy.org•94 days ago

For those interested here's a recent study on this topic (I'm not involved): 🧪🔭

ututuy.org•95 days ago

Got some glitches in the animation. But the observant might notice that I used the "cosmic microwave background" (CMB) as a texture for the core. #Geophysicists abbreviate the "core-mantle boundary" as the #CMB too!

timtheld.bsky.social•95 days ago

That's awesome.

I knew the core moved independently of the mantle but I think this is the first time I've ever seen an animation of it.

Great Job.

carolinecarter1.bsky.social•77 days ago

It looks spectacular.

tg626.net•95 days ago

What's the time frame? Does that wobble correlate with the procession of the magnetic deviation?

ututuy.org•94 days ago

The mantle spin axis is continuously changing direction, this is the Earth’s precession. Seen from outside, in inertial space, it describes a cone, period is 26000 years (not shown in this animation). But the motion of the core, seen from the mantle as in the animation, is diurnal.

ututuy.org•94 days ago

The Earth’s magnetic field is not involved, at least not directly.

classicrat.bsky.social•95 days ago

What about the inner core?

ututuy.org•94 days ago

Good question! The solid inner core spin axis is also misaligned with respect to the liquid outer core, but the angle is way smaller, not easy to measure.

thedragonllama.bsky.social•94 days ago

...the Cluster...

rockalot.bsky.social•95 days ago

This is slightly terrifying

thisilove.bsky.social•95 days ago

Shouldn't this be a disc that's flat because obviously the earth is flat because let me show you these YouTube videos from insane people they'll totally convince you hold on

broadsheetcast.bsky.social•94 days ago

Whenever I search for those videos, I can only find debunk videos. Suspicious.

nees5959.bsky.social•94 days ago

Kinda like an 8 ball.

stevekarmazenuk.bsky.social•95 days ago

FR this is an excellent graphic, demonstrates the principle elegantly, but I keep expecting a news presenter in their 40's to pop up onscreen to announce news in one of several different available British accents.

black-materia.bsky.social•95 days ago

I bet if you were to summon with me I could make a meteor that would make it all the way to the core, Santiago.

brownbats.bsky.social•95 days ago

Neat

collectivided.bsky.social•94 days ago

surely this is a huge component of the geodynamo process of electrical currents near the boundary layer that generates the planet's magnetic field. cool

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