An important part of being a scientist is being cynical enough about a suspicious new result that you check the…

An important part of being a scientist is being cynical enough about a suspicious new result that you check the sources. +Francesco Busiello did that and explains in this great post where this talk of an “ocean deep inside the Earth” you heard about on the news comes from. Spoiler alert: it’s not an ocean.

Originally shared by Francesco Busiello

There is no ocean deep inside the earth

“In what sounds like a chapter from Journey to the Center of the Earth, the chemical makeup of a tiny, extremely rare gemstone has made researchers think there’s a massive water reservoir hundreds of miles under the earth.”

In the last couple of days newspapers and other media outlets have reported what they’ve been calling “an ocean deep inside the earth”. “What if the outermost layer of the earth was floating on a boundless sea, bigger than all of the ones present on the surface?”(translation mine) writes Laura Berardi on ilFattoQuotidiano, which is normally quite a decent newspaper (though their track record on scientific reporting is middling at best).

There could be a large body of water buried deep beneath the Earth’s surface containing as much water as in every ocean combined, according to new scientific research. You know, just your average secret trove of buried water to sustain all life on Earth.

-The Wire

Note that most of these “articles” skirt around the issue of well, telling the truth, by using “what if” statements. This would all be well and good if these hypothesised scenarios were not completely misleading. They’re a very cheap way of getting clicks. “There is an ocean beneath you!” is more interesting for the average reader than an accurate report of a geology paper.

It shouldn’t be this way, but it is. And it sucks. We deserve better.

But anyway, let’s take a look at the aforementioned paper.

Pearson D.G. et al. analysed a sample of ringwoodite, trapped inside a diamond. This diamond was originally formed deep in the earth’s mantle and it only reached the surface thanks to a volcanic eruption (it traveled 525km up to the surface!). During its trip it got battered and bruised and has no real economic value (no one wants a ring with a misshapen diamond, unless you were a geologist, maybe).

These erupted diamonds, however, are of great interest to geologist because they give us a way of analysing the composition of the mantle.

Geologists think that a lot of the earth’s mantle is composed of olivine (a mineral also known as peridot). Olivine, at high pressure, changes its crystal structure and turns into ringwoodite, which is the material analysed by Pearson et al.

We know that olivine turns into ringwoodite because scientists have created it in the lab or found it in meteorites. But this is the first evidence that ringwoodite does form in the mantle which, so far, had only been an hypothesis.

What does this mean? Because ringwoodite can contain up to 2.6% of its weight in water, it follows that:

a) the olivine at a particular depth (and hence pressure) is transformed into ringwoodite

b) the ringwoodite can contain some water inside its crystal structure


c) there is a lot of water in the mantle

Which is where the whole “ocean” thing comes from. Except that, not really.

Calling it “water” is not exactly right. It’s not liquid water, which is what we visualise when saying the word “water”. It’s hydrogen and oxygen atoms trapped inside the crystal structure of ringwoodite.

It would be more appropriate to call it H2O, or even better, hydroxide ions.

It’s an important discovery, and one that will contribute to the answer to the “is there water in the mantle?” question and it’s of great interest to geology.

However, there are no oceans deep inside the earth. No vast lakes of liquid water.

But I guess, “The earth’s mantle may contain large amounts of hydroxide ions trapped in ringwoodite’s crystal structure” gets less clicks.


This post was originally published here:

References and further reading


DG Pearson et al. (2014) – “Hydrous mantle transition zone indicated by ringwoodite included within diamond” – Nature

Articles worth reading

Rare Diamond Reveals Earth’s Interior is All Wet – LiveScience

Rare Diamond Confirms That Earth’s Mantle Holds an Ocean’s Worth of Water – Scientific American

Articles quoted but not worth reading

Un piccolo diamante svela che sotto la Terra ci sono sconfinati oceani – ilFattoQuotidiano

Earth May Have Massive Subterranean Water Reservoir, Bigger Than All Our Oceans – The Wire



Photo by Thiago Fioreze

Join the Conversation


  1. This is similar to the science field of research we call Astro-Biology, in other words, the science of “Could”

    I find this same issue of other areas of biology where if you question the results which are popular with the majority, you’re demonized as an anti-science heretic. The health and sad state of our planet shows how much is not correctly known nor understood.


  2. This may be of interest to some if you enjoy the subject of water. An Emeritus Professor of Applied Science London South Bank University named Martin Chaplin developed a website where he has referenced the multiple anomalous properties of water structure and behavior under varying conditions. For many it will be boring, but worth a try. I have been fascinated with water for three decades now. Mostly with regards plants within and ecosystem and developing strategies reestablishing habitats with such phenomena as hydraulic lift & redistribution and also hydraulic descent in mind. Anyway without boring folks any longer, here is the link:


  3. I have a question… I thought there was a burning hot core in the center of the earth. Is this not that deep? Or are we just magically changing a piece of scientific “fact” that has been taught for more than a few years?


  4. Charles the problem is with most Journals and Science writers when it comes to the public, you have got to create a sensational sexy title to grab attention from an otherwise disconnected public This is certainly not the first time this subject has been around, in fact I have seen it on the US Geological Society’s website back in 2009, but even then I was not thinking it to be an actual pure water deep earth ocean like some “Journey to the Center of the Earth” fantasy. I already knew that oxygen and hydrogen are locked up inside various mineral compounds. But nevertheless we live in a world where debates about words/terms seems to be a recreational sport of sorts among intellectuals. Actually in every article I have ever read, I don’t believe I have seen where the authors spoke of actual underground oceans or seas, but always the mix of H2O within other elements. 

    It has been suggested that it being part of other materials allows for better lubrication of plates and fluid dynamics  of things like lava etc.  But I am still not sure. It is interesting how this water comes to the surface on ocean floors by means of hydrothermal vents or black smokers. One documentary I watched where a camera was placed near the vent mouth as close as possible, then zoomed in on the immediate water coming from the vent only showed super heated water heat waves with lack of bubbles associated with normal boiling. It was explained that under intense pressures of deep ocean where these are located that water behaves differently, but once coming into surrounding colder waters, the bubbles would manifest themselves, along with any mineral content which the cloudiness would indicate.

    In one debate years ago one dogmatic individual I had a discussion with on this insisted that water would explode under superheated conditions and the earth would blow up so no water existed within the mantel. However the explanation I saw in the documentary actually explained this phenomena very well. Even still we live in a world where people thrive on controversy and combativeness. Semantics will always be a straw in the eye or a straining of the gnat from the milk. Still an interesting subject though.


  5. Actually, that picture reminds me of when I use to leave for work at 4:00 in the morning from the mountains above Palm Springs where I use to live and drive south towards Mexico to El Centro. On my left I’d drive past the Salton Sea just about the time of the light getting bright on the eastern horizon over in Arizona. Then I’d see such clouds, because after all it was the Monsoon season. There would always be one or two large singular clouds among the scattered smaller ones which would have streaks of rainfall patterns streaming down below them onto the sea’s surface and once in a while lightning would flash. Yeah, it was beautiful.


  6. @ Francesco: OMG! I just googled ringwoodite and WIKIPEDIA states “Ringwoodite is notable for being able to contain water within its structure, present not as a liquid but as hydroxide ions (oxygen and hydrogen atoms bound together).[4] Combined with evidence of its occurrence deep in the Earth’s mantle, this suggests that there is an ocean’s equivalent of water in the mantle transition zone from 410km to 660 km deep” So obviously mis-information on the cloud extends to every corner imaginable.  Geez!!!




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