Guest oy vey by David Middleton
First we learn that climate change is dissolving the seafloor and now we find out that Earth is devouring its own oceans (like it could be devouring some other planet’s oceans)… And it’s three times as bad as “previously thought” (is it ever three times better than previously thought?).
Live Science Planet Earth
The Earth Is Eating Its Own Oceans
By Stephanie Pappas, Live Science Contributor | November 14, 2018
As Earth’s tectonic plates dive beneath one another, they drag three times as much water into the planet’s interior as previously thought.
Those are the results of a new paper published today (Nov. 14) in the journal Nature. Using the natural seismic rumblings of the earthquake-prone subduction zone at the Marianas trench, where the Pacific plate is sliding beneath the Philippine plate, researchers were able to estimate how much water gets incorporated into the rocks that dive deep below the surface. [In Photos: Ocean Hidden Beneath Earth’s Surface]
The find has major ramifications for understanding Earth’s deep water cycle, wrote marine geology and geophysics researcher Donna Shillington of the Lamont-Doherty Earth Observatory at Columbia University in an op-ed accompanying the new paper. Water beneath the surface of the Earth can contribute to the development of magma and can lubricate faults, making earthquakes more likely, wrote Shillington, who was not involved in the new research.
[…]
And that raises some questions: The water that goes down must come up, usually in the contents of volcanic eruptions. The new estimate of how much water is going down is larger than estimates of how much is being emitted by volcanos, meaning scientists are missing something in their estimates, the researchers said. There is no missing water in the oceans, Cai said. That means the amount of water dragged down into the crust and the amount spouted back out should be about equal. The fact that they aren’t suggests that there’s something about how water moves through the interior of Earth that scientists don’t yet understand.
“Many more studies need to be focused on this aspect,” Cai said.
Well, at least they aren’t blaming this on climate change or President Trump.
All seriousness aside, this is how plate tectonics work. In the absences of oceans, plate tectonics might not be possible.
Water plays an important role in mantle convection. In the ductile creep regime, the viscosity of wet rocks is weaker than the viscosity of dry rocks by several orders of magnitude. In the brittle regime, the most substantial effect is probably serpentinization which can reduce the friction coefficient by a factor of 2 or more. The difference between the strength of a wet lithosphere and that of a dry lithosphere seems to be big enough to control the very existence of plate tectonics. Because of dehydration due to partial melting the oceanic lithosphere is expected to be essentially dry above some critical depth, around 60-80 km. This would make the lithosphere strong enough to prevent plate motion. Percolation of water from the surface can be the main mechanism supplying water to the upper parts of the lithosphere. This implies that liquid water can be crucial for maintaining plate tectonics. On the other hand, the surface temperature is above the freezing point because of the greenhouse gases such as carbon dioxide. A simple model shows that if the blackbody temperature of the Earth is slightly below the freezing point of water, the feedback between plate tectonics, volcanism, and water and carbon cycles can result in an equilibrium state in which the surface temperature is established within the stability field of liquid water.
The fact that there’s no water missing from the oceans simply means that the Earth must also be spewing out three times as much water vapor (and other gases) from volcanic sources than previously thought. One of the “other gases” emitted by volcanoes is the evil, climate wrecking carbon dioxide. Wouldn’t it be “funny” if volcanoes accounted for three times as much of the CO2 in the atmosphere than previously thought? But then again, they wouldn’t notice it… because volcanoes aren’t in the flashlight beam…
Why?
The article was actually fairly well written, but the headline was simply stupid.
The role that subducted water plays in plate tectonics isn’t really a “new thing.” Why on Earth would a competent science journalist title the article, “The Earth Is Eating Its Own Oceans”?
Stephanie Pappas, Live Science Contributor
Stephanie Pappas is a contributing writer for Live Science. She covers the world of human and animal behavior, as well as paleontology and other science topics. Stephanie has a Bachelor of Arts in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz. She has ducked under a glacier in Switzerland and poked hot lava with a stick in Hawaii. Stephanie hails from East Tennessee, the global center for salamander diversity.
That’s why.
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We’ll just have to start detonating enormous fusion bombs in strategic spots under the crust to vaporize that trapped water & blow it out into the atmosphere to replenish the oceans. Or, just direct some water-ice asteroids or comets softly down into the oceans, then aim a giant orbiting mirror melt them. There ya go.
The comments above show an almost wilful ignorance of the science of rock morphology. I am not an expert but how some of the above statements about water being scraped of rocks can have a name put to them asks serious questions regarding the authors ability to do the most basic research.. Check out “inclusion” in the rock morphology sense, guys. Also note the hydrogen and oxygen can become other chemicals in the mantle and still re emerge as water through the cycle of tectonic regeneration. It’s 20KBar and over 1500 degrees just under the thin crustal scab we live on, stuck on the visco elastic mass of the Earth’s interior by gravity alone.
MEANWHILE: I have a paper that is w.i.p on SSRN that attempts to quantify total oceanic magma release, which is far more, and far more variable, than modellers assert. Those of you who are numerate and have a basic grasp of the natural world and physics fact might find it of interest, to see if it has merit. The probable realities may also blow your socks off. I started with the suggestion from the University of Oregon that there were 1 Million oceanic volcanoes, but later realised the effect quantified could be achieved with 100,000, if correct. You decide.
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3259379
If my quantification and explanation of variability has merit it can account for climate variability in the single decimal W/m^2 range and also ocean level rise at the levels we see today, and the interglacial ice age event every 100Ka, simply by the variable amount of MAGMA entering the oceans from volcanoes. Not that CO2 affects much except plant growth. Much more magma than advertised, and much more variable than “atmosphere only” CO2 scapegoating models assume, while turning CO2 up to 11 on the climate model mixer to drown out the rest of the band in return for their grants.
Obs, CO2, water vapour and all the other stuff will be increased by a similar amount as is magma, versus the obvious underestimate of geologists “concensus” (We don’t have a clue so we’ll agree on a number to pretend expertise and all stick to it, keep taking the grants). The “consensus” on magma entering the ocean is 3 or 4 Cubic Kilometres pa, repeated evry TV documentary by celebrity geologists. They must all suffer from a basic lack of logical numeracy as that would leave a VERY large hole in the planet, it isn’t even enough to fill the 75,000 Km of 7Km deep cracks between divergent plates, which I make to be 10 cubic kilometres at 2cm pa. In fact the average is much higher, which means >10K cubic kilometres pa, Obs, Duh. Don’t trust me, “do the arithmatic” (David MacKay).
Technically illiterate volcanologists exist in some cosy world of taxpayer funded trips to interesting places, reporting on things we cannot change, can never test their opinions of in many cases because of the time scales and extreme conditions involved, and avoid any controversy. Certainly not offering any inconvenient challenges to any of the established institutional consensuses from outside regarding their subject. Why spoil an easy number?
E.G. The University that suggest the 3 or 4 cubic kilometres pa of magma entering the oceans is the same one that suggests 1 Million Volcanoes under the ocean, which it appears from the research to date would clearly emit some 5000 times that on their own, w/o the divergent plates gap to fill. Left and right hand, etc. Links and full references are in the paper.
LESSON: You can’t make it up, that’s the job of “experts on everything”………… “with a typewriter and an opinion” (Feynman). Most “science” that is written currently on the subject of planetary systems lacks data, logic, knowledge and mostly offers such vague propositions they cannot be proved right or wrong as “science”. nice work if you can get it.
So these author “experts” mainly qualify as “just another person with an opinion” in provable science fact. Not a basis for action. I am not an expert in geophysics, BTW. Just a physicist and engineer with some data and a grasp of the laws of physics, trying to form hypotheses for others to challenge with their physical reality, versus the new science of presenting a consensus of modellers, perhaps their new collective noun, who programme their models with assumptions that “prove” whatever the idea was they were funded and programmed to prove using “data and a definition of success”. Or what some bloke who doesn’t want to do the physics or the research and arithmatic thinks “makes sense”.
Neither the expert or the delusional prove any laws. Or even cause and effect. Perhaps correlation. Not real science. 21st Century post industrial religion? But check out the magma hypothesis, I think it has legs, just needs track to run on. Send challenges. This is serious science. Probably.
I would have thought that most readers – and most certainly David Middleton – were aware that the author of an article and the author of the headline for said article are rarely the same person. Headline editors primary goal is to attract eyeballs, not accurately capture the thrust of the article.
If this keeps up our children won’t know what oceans are. /sarc.
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‘That’s why.’ That made me chuckle. I almost spit my coffee. And yes i’m drinking cofofee @ur momisugly 8PMU.S. eastern time.
The role that subducted water plays in plate tectonics isn’t really a “new thing.”
No – and the logical fallacy of “nothing happened until we discovered it” is not new either but seems to be becoming more prevalent with increasing politicisation / dumbing down of science.
Robert of Texas says: November 15, 2018 at 5:01 pm: Robert, yes, I happen to live on the mafic zone of a Kear-Marshall zone; Kaipara and the rest of Northland NZ. Some 40mi East is the felsic zone. The subduction starts East of that as the West Pacific Oceanic Plate dives under/pushes up the NZ Continental Plate. Shallow zones melt felsic (sandy) eruptive material which has erupted on the surface, often still underwater then. This is lower-melting point rock hence the shallow depth. The subduction being deeper 40mi West, tougher Mafic (metallic) rock is melted too and can rise to form Stratovolanoes. This Peninsula’s c.300mi is perhaps the densest known volcanic zone on Earth…. We have very good Geological studies of it all, recently published in a fascinating Textbook (Out of the Ocean into the Fire. Ed. Bruce W. Hayward). Luckily the active volcanics are now further south and north.
PS: The ocean floor ir renewed/destroyed about every 200 million years, So, about 20-25 times. Swallow that and digest it! 🙂
Some places are cut off from these cycles of creation and destruction.
Gulf of Mexico?
And it’s three times as bad as “previously thought” (is it ever three times better than previous thought?).
This costs an extra charge!
Why should water with specific gravity 1 slip past heavier mantle components past the center of the earth. This article is a hardener for the carnival season.