Posted on 03/11/2022 6:57:09 AM PST by Red Badger
Rotating 3D view of Earth's blobs. (Cottaar & Lekic/Geophysical Journal International, 2016)
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Earth's interior is not a uniform stack of layers. Deep in its thick middle layer lie two colossal blobs of thermo-chemical material.
To this day, scientists still don't know where both of these colossal structures came from or why they have such different heights, but a new set of geodynamic models has landed on a possible answer to the latter mystery.
These hidden reservoirs are located on opposite sides of the world, and judging from the deep propagation of seismic waves, the blob under the African continent is more than twice as high as the one under the Pacific ocean.
After running hundreds of simulations, the authors of the new study think the blob under the African continent is less dense and less stable than its Pacific counterpart, and that's why it's so much taller.
"Our calculations found that the initial volume of the blobs does not affect their height," explains geologist Qian Yuan from Arizona State University.
"The height of the blobs is mostly controlled by how dense they are and the viscosity of the surrounding mantle." 
3D view of the blob in Earth's mantle beneath Africa. (Mingming Li/ASU)
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One of the principal layers inside Earth is the hot and slightly goopy mess known as the mantle, a layer of silicate rock that sits between our planet's core and its crust. While the mantle is mostly solid, it behaves sort of like tar on longer timescales.
Over time, columns of hot magma rock gradually rise through the mantle and are thought to contribute to volcanic activity on the planet's surface.
Understanding what's going on in the mantle is thus an important endeavor in geology.
The Pacific and African blobs were first discovered in the 1980s. In scientific terms, these 'superplumes' are known as large low-shear-velocity provinces (LLSVPs).
Compared to the Pacific LLSVP, the current study found the African LLSVP stretches about 1,000 kilometers higher (621 miles), which supports previous estimates.
This vast height difference suggests both of these blobs have different compositions. How this impacts the surrounding mantle, however, is unclear.
Perhaps the less stable nature of the African pile, for instance, can explain why there is such intense volcanism in some regions of the continent. It could also impact the movement of tectonic plates, which float on the mantle.
Other seismic models have found the African LLSVP stretches up to 1,500 kilometers above the outer core, whereas the Pacific LLSVP reaches 800 kilometers high at max.
In lab experiments that seek to replicate Earth's interior, both the African and Pacific piles appear to oscillate up and down through the mantle.
The authors of the current study say this supports their interpretation that the African LLSVP is probably unstable, and the same could go for the Pacific LLSVP, although their models didn't show this.
The different compositions of the Pacific and African LLSVPs could also be explained by their origins. Scientists still don't know where these blobs came from, but there are two main theories.
One is that the piles are made from subducted tectonic plates, which slip into the mantle, are super-heated and gradually fall downwards, contributing to the blob.
Another theory is that the blobs are remnants of the ancient collision between Earth and the protoplanet Thea, which gave us our Moon.
The theories are not mutually exclusive, either. For instance, perhaps Thea contributed more to one blob; this could be part of the reason why they look so different today.
"Our combination of the analysis of seismic results and the geodynamic modeling provides new insights on the nature of the Earth's largest structures in the deep interior and their interaction with the surrounding mantle," says Yuan.
"This work has far-reaching implications for scientists trying to understand the present-day status and the evolution of the deep mantle structure, and the nature of mantle convection."
The study was published in Nature Geoscience.
Geologists Have Closely Analyzed Two Bizarre ‘Blobs’ Detected Deep Inside Earth and after decades of study, numerous peer reviewed papers, the scientific community has determined that they are in fact “Blobs”.
What’s really asinine is that our “scientists” can drum up billions of dollars to research, postulate and theorize what’s on/in a planet millions/billions of light years from Earth, but can’t do it in their own backyard.
What’s really asinine is that our “scientists” can drum up billions of dollars to research, postulate and theorize what’s on/in a planet millions/billions of light years from Earth, but can’t do it in their own backyard.
Oil.
It is all just based on seismic modeling. I have drilled several dry holes due to “seismic modeling.”
LOL! I can imagine Karens looking at that poster showing those 30-year-old teenagers with cigarettes sticking out of their mouths and just losing their minds.
Folks,
Is not this article good science? So much unlike the “science of answers”.
Good science leads you to more questions and closer to the truth, but you NEVER quite get to the final answer, the universal theory. Why is that?
That nature of humans is we want answers, not more questions. In fact, we want simple answers so that we can feel in control.
But in reality, there is a simple answer to all Questions. The answer to every question is God. But that answer gives us indigestion and headaches.........................
The new crop of Oil made at the core ,LOL
Even if the work/theory later goes belly-up, there are technical/engineering spin-offs (maybe not directly but indirectly!) even from something this esoteric.
I see what you did there...
It was intended to be. You would really be unsettled if you knew that your were racing along the continent you are on and will soon collide into the nearest continent. Better start packing because the collision will be soon, and probably less than a few million years. LOL.
“ Rosie O’Donnell and ... ?”
Stacey Abrams, of course.
I guess since it “doesn’t work”, that’s why the industry spends oodles & oodles of money doing seismic modeling!
When I was in the industry in the 1970s the claim was 1 hole out of 30 paid off. (Note I never bothered to check the claim! Saw no need to!) I am sure its a better ratio now.
It’s lots of yummy oil waiting to go in my gas tank.
I understand basic research and it’s importance.
But the way of getting attention is to have an outlandish theory these days. The further out the theory, the more attention you get. It is not built on prior truths learned.
What reward do you get for proving someone else’s prior work?
Very little research is built on prior learning. The goal is getting closer to the truth.
This article was good I thought. It wants to get closer to the truth.
I would bet that you are right.
There is enough oil to supply ALL man’s needs for at least a thousand years............
Even if the work/theory later goes belly-up, there are technical/engineering spin-offs (maybe not directly but indirectly!) even from something this esoteric.
I have looked at some of the programs at science/engineering conventions. It might as well have been a comic con convention.
Take a really good look at the research coming out of our universities. This is not to say there is not any good research, but someone should have said NO to a lot of it.
No argument from me. Unfortunately “the system” for both advanced degrees (MS, PhD) for students, promotion and tenure for faculty require “research”. Should such a system be replaced? Yes ! But with what?
Questions that have to be answered for a replacement system to work
1. How do you train a student in “research” without doing “research” even “bad research” is better then no “research” or so its thought.
2. How do you measure faculty performance?
3. How do you even measure good teaching by faculty? Letting the students fill out evaluaion forms? Easily defeated ! If yu give out A’s all the students love you!
And here I am only talking about science & engineering!
Humanities, liberal arts & social sciences are just publishing personal prejudices and calling it “unbiased reserach”. Of course in the academic culture it has the same cache as research in medicine, science & engineering.
Obama’s birth certificate and Joes cognitive test. 😉
The images demonstrate what I always suspected the natural state was - structures that are less uniform than the standard science textbooks always portrayed.
Chris christie
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