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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Maybe this is why those pesky oceans refuse to accelerate their rising and swamp us all!
Alexandria Ocasio-Cortez wants to pass a law to stop the Earth from eating its own oceans by 2010.
Just testing a new Scare Tactic for when the climate change scare tactic fall apart. Hang Tight, film at midnight.And for sure a movie in the works.
What about the salt?
The idea that water can even exist as a vapor above the triple point is absurd and shows the author was never exposed to the concept of basic thermodynamics. Above the critical pressure and temperature water does a lot ov very strange things and reacts with many rocks and minerals in unique ways and is chemically captured. No real mystery about it though.
Phase diagrams will always be mysteries… 😉
From the linguistic/grammatical pedantry department:
“The Earth Is Eating Its Own Oceans”
Shouldn’t that be “The Earth Is Drinking Its Own Oceans”?
Here’s a somewhat more serious thought from someone who has watched the astonishing evolution of geological knowledge over 5 decades: I submit that the “missing” water is probably being discharged from hydrothermal vents on the ocean floor that haven’t been mapped yet.
Which calls for a Talking Heads quote…
https://youtu.be/5IsSpAOD6K8
I submit that the “missing” water is probably being discharged from hydrothermal vents on the ocean floor that haven’t been mapped yet.
I submit the “missing” water is hanging out with Trenberth’s “missing” heat at the “hide the decline” bar and grill.
“Many more studies need to be focused on this aspect,” Cai said.
Yes, there’s no question we need to pour even more prodigious sums of public money into “science” which adds to our ever-growing pile of useless knowledge about things that actually don’t matter.
They now say that most of the water on earth is deep within the earth and could take part in the earth water cycle.
“It is estimated an additional 1.5 to eleven times the amount of water in the oceans is contained in the Earth’s interior, and some scientists have hypothesized that the water in the mantle is part of a “whole-Earth water cycle”.
The water in the mantle is dissolved in various minerals near the transition zone between Earth’s upper and lower mantle.”
https://en.wikipedia.org/wiki/Water_distribution_on_Earth#Water_in_Earth's_mantle
Soon there’ll be no oceans left. We’re doomed.
Fourth Law of Thermodynamics:
It’s ALWAYS Three Times Worse Than We Thought.
Well at least Trenbreth knows where took look for his lost deep ocean heat now, down an ocean plug hole, whudda guessed, its like finding out yer best m8s innit.
Well at least Trenbreth knows where to look for his lost deep ocean heat now, down an ocean plug hole, whudda guessed, its like finding out yer best m8s gay innit.
It’s been hinted at above but I don’t think it’s been stated clearly: large amounts of liquid water are not being sucked down in subduction zones. What is going down is vast amounts of hydrous minerals, most commonly clays and chlorite but also many others. Even the seafloor basalts themselves undergo substantial deuteric (during magma cooling) alteration due to interaction with seawater resulting in hydrous minerals throughout.
As these minerals go down with the subducting slab and are subjected to increasing heat and pressure water is released and the minerals alter to less hydrous and then anhydrous species. Some of the resulting water finds its way into volcanic systems, but anywhere anyone drills, if you go below the groundwater (fresh water) level there is always salt water.
The deepest well I know of is this one, drilled in granite, still hitting salt water:
https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole
My understanding is that groundwater becomes salty over time just sitting down there.
And that therefore, all fresh groundwater is relatively recent.
Ogallala aquifer?
Pleistocene origin.
Not something I have researched in depth or anything, but it makes sense…water is the great dissolver.
Isn’t this consistent with the alternative non-fossil theory of oil formation – water plus limestone under extreme pressure creates hydrocarbons – no animals or plants need to die.
Based on this theory the Russians in particular have made major discoveries of hydrocarbons/
I know the Russians, far from the continental margins, have approached oil and gas differently and done just fine. But it’s the passive margins, and relatively shallow, where western companies have found so much oil and gas. Too much heat and pressure and the oil breaks down and your left with just gas. Maybe some of those Russian deposits are ancient margins that have long since closed. Certainly Russian deposits are heavy on gas. I really don’t know much about them though, this is just of the top of the head conjecture.
I’m also not a chemist but I don’t see how you can get enough hydrogen to make hydrocarbons from just water and limestone. The liquid left behind is going to be as alkaline as bleach, and that’s just not what you find.
The big russian fields in West Siberia have perfectly normal shaly source rock, the Jurassic Bazhenov shale, and the oil originated in the usual way as the Turgai Sea closed.
And if the Russians learn how to frack the Bazhenov shale OPEC is finished. The Permian Basin is small in comparison.
As I remember the Laws of Thermodynamics:
The First was entropy, which states: “It’s going to get a lot worse before it gets any better.”
The Second was entropy —“Who says it is going to get any better?”
Late but neat estimate, general principles but not specifics recalled from a maybe faulty memory.
The biologic ocean carbon sink is calciforming algae. So long as these die and their detritus rains on depths less than the ~CCD dissolution boundary (roughly 4km depth) then carbonate rock forms.
Unless this rovk is recycled via subduction vulcanism, the atmosphere would be biologically so depleted of CO2 that life would cease in about 3.5 million years.
We much underappreciate plate tectonics, subduction zones, and andesic volcanos.
Wait till they discover the amount of atmosphere disappearing into automotive vacuum leaks every year and demand cars be banned because of it.
And guess where the ocean salts end up. Some of them end up on the world’s largest salt lake: Salar Unyui, in Bolivia, at an elevation of 3300 meters. This is also where they find the lithium-charged salts. Subducting oceanic slabs, full of seawater feed into the geater Andes mountain volcanoes, and returns the salts and other minerals, including metals to the surface via volcanic processes. See the article in Marine and Petroleum Geology: Hovland et al., 2018: “Large salt accumulations as a consequence of hydrothermal processes associated with
‘Wilson cycles’: A review Part 1: Towards a new understanding” The article is available on ResearchGate.net
Yes, inland salt lakes are chemically different from near-coastal ones where much or all the salt is ultimately derived from the sea.
But Hovland et al. are overstating their case. Salt lakes/pans will form in any endorheic environment, even in total absence of volcanic, hydrothermal or tectonic activity, e. g. Etosha pan.
Humans did it.
It is perfectly possible that subduction could be net removing water from the oceans at the present time. Plate tectonic activity varies over geological time and so does sea level. As a matter of fact over geological times sea level has varied rather more than is easily explained.
However it is probably impossible to prove it. It might be possible to roughly calculate the amount of water being subducted, but not the amount being erupted from submarine volcanoes or seeping up in geothermic fields, at least not at present. As a matter of fact it is only quite recently that it has been discovered how extensive such activity is on mid-ocean ridges and most of the ocean floor is still completely unexplored. And who would care to guess how much H2O is coming out of the world’s largest rift valley underneath the West Antarctic Ice?
there is a global center for salamander diversity?
Who knew?
So they estimated the water during normal plate tectonics and said but no water is missing from the oceans. OK……
Yet failed to recognize OTHER ocean floor structures and processes and concluded that the Earth is eating water. Uh huh. Sure.
Seriously a whole global center for salamander diversity? Really? That’s more interesting than 7th grade Earth Science jacked up to MONSTER OF THE WEEK headlines.
“The water that goes down must come up”
Must it though? with all the heat, molten minerals, pressure, does none of it gets decomposed to hydrogen and Oxygen and ends up incorporated into other compounds? curiosity makes me ask…..
Oh, I finally figured out the purpose of Stephanie’s attempt at purveying information. There’s nothing going on to create panic attacks in the general population, hence the half-baked and not particularly accurate article written as a means of injecting ‘carbon dioxide is a greenhouse gas CLIMATE CHANGE’ into the piece. And besides, she gets paid to do that, so CLIMATE CHANGE has to go in there somewhere. Natural processes are somehow threats and she has to relate it all to CLIMATE CHANGE.
Got it. Moving on.
No, … then relate it to humans … then move on.
1) Take phenomena which has been operative for 4 billion years
2) find your previous estimate of the magnitude was hugely wrong
3) cover that by generating headlines about worse than we thought apocalypse
4) get lots of media
“Science”
‘Gobbling’ is melodramatic.
Subduction rates range from 2 to 8 centimeters per year. Yeah, an inch or two. Water can surely get out of the way. If it wants to.