From the “but wait, I thought only CO2 had the power to change the climate” department comes this revelation.
New research suggests that dawn of plate tectonics could have turned Earth into snowball
A research duo from The University of Texas at Austin and UT Dallas have put forward a hypothesis that links the dawn of plate tectonics with “snowball Earth”–a period of climate change that sent the planet into a deep freeze that lasted millions of years.
They expect their hypothesis to generate controversy. Geologists usually place the start of plate tectonics at about 3 billion years ago, while the new hypothesis puts the process in a much younger era known as the Neoproterozoic, which occurred about 542 million to 1 billion years ago.
“If you look at the preserved record, diagnostic evidence for modern plate tectonics involving deep subduction is mainly Neoproterozoic and younger,” said co-author Nathaniel Miller, a research scientist in the Department of Geological Sciences at the UT Austin Jackson School of Geosciences. “But most people think we had this much earlier in Earth history.”
Miller and Robert Stern, a professor in the UT Dallas Department of Geosciences, examined a suite of published scientific data on the geological activity during the Neoproterozoic–the era of snowball Earth–and found a link between plate tectonics and a cooling world.
The research was published online in December 2017 and in the April print edition of the journal Terra Nova.
The Earth is the only planet known to have plate tectonics, with its crust and upper mantle being made up of distinct pieces that move slowly and independently, creating and destroying landforms and producing volcanoes and large earthquakes.
Plate tectonics is one of the most fundamental processes that shape the planet, and most geoscientists believe it has been active for most of the planet’s 4.5 billion-year history. However, according to Miller and Stern, there are a variety of traces in the geologic record that could be consistent with plate tectonics not getting started until the Neoproterozoic.
For example, rock formations, gemstones and chemical signatures known to be associated with plate tectonics date only as far back as this period; and computer models suggest that the Earth didn’t cool to temperatures required for plate tectonic activity until then. The authors also note the geologic interval preceding the Neoproterozoic shows a lack of geological activity–a feature that has it earned it the nickname “the boring billion,” and which could indicate that the Earth was covered by a single lithospheric lid rather than the many moving plates of today.
The overlap in timing between the appearance of these signatures of plate tectonic activity and Earth’s snowball phase led the researchers to think that they could be related, and that the drastic climate change could be a consequence of the Earth’s transition from single lid to plate tectonics.
“This climate crisis could have been caused by a number of proximal causes, but the overall great cause was this revolution in Earth’s tectonic style,” said Stern.
The paper lists 22 proposed ways plate tectonic activity could have brought about global cooling that caused the Earth to be covered from pole-to-pole with ice. They include explosive volcanoes cooling the planet by releasing sulfur into the atmosphere; the shifting of the plates changing the planet’s rotational axis; and increased rock weathering pulling CO2–a greenhouse gas–out of the atmosphere and back into the Earth.
In the study, researchers also considered potential non-tectonic reasons for cooling that came from space–from asteroid impacts, to the collapse of ice rings that could have formed around Earth. If these were the cause of snowball Earth, Stern and Miller’s theory falls apart–but there’s not much evidence to support these triggers.
While all the potential cooling mechanisms were first described in other research papers, Stern said that he and Miller are the first to raise the possibility that each could be related to the transition to plate tectonics–an idea that he describes as radical.
“People have been saying for a long time that we have always had plate tectonics…but I think this might be a failure of imagination,” Stern said.
Graham Shields, a professor of geology at the University College London who was not involved with the study, said that the theory Miller and Stern propose needs more evidence before snowball Earth can be linked to the start of tectonics rather than just a period of tectonic activity.
“How do we distinguish their tectonic onset hypothesis from other hypotheses, most of which are also related to tectonics and the well-established supercontinent cycle,” Graham wrote in an email reply.
The authors note that their paper presents a possible scenario in Earth’s history, and that more research is required to test the link between the dawn of plate tectonics and snowball Earth. They hope that this research will lead other geoscientists to consider the evidence and test the hypothesis.
“Revolutions in our field don’t happen often or very easily,” Stern said. “You plant ideas and then you go and look for more data that either supports them or refutes them.”
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The paper: https://onlinelibrary.wiley.com/doi/abs/10.1111/ter.12321
Abstract:
When Earth’s tectonic style transitioned from stagnant lid (single plate) to the modern episode of plate tectonics is important but unresolved, and all lines of evidence should be considered, including the climate record. The transition should have disturbed the oceans and atmosphere by redistributing continents, increasing explosive arc volcanism, stimulating mantle plumes and disrupting climate equilibrium established by the previous balance of silicate‐weathering greenhouse gas feedbacks. Formation of subduction zones would redistribute mass sufficiently to cause true polar wander if the subducted slabs were added in the upper mantle at intermediate to high latitudes. The Neoproterozoic Snowball Earth climate crisis may reflect this transition. The transition to plate tectonics is compatible with nearly all proposed geodynamic and oceanographic triggers for Neoproterozoic Snowball Earth events, and could also have contributed to biological triggers. Only extraterrestrial triggers cannot be reconciled with the hypothesis that the Neoproterozoic climate crisis was caused by a prolonged (200–250 m.y.) transition to plate tectonics.
So 1360 W/m^2 at the equator isn’t enough to prevent freezing? 10th that amount works t9 day.
With Antarctic like levels of albedo? There would be rather fewer incident watts at the equator.
The sun was weaker in both spectrum and luminosity 4 to 2 Ga. So the Earth was more prone to freeze overs. What kept it from permanent freeze over was a likely higher surface pressure/density. CO2 ( molar mass: 44) is both a GHG and its molar mass is higher than O2 (32), N2 (28), and H2O (34), Ar (40). Thus early Earth likely had a denser lower atmosphere, but as O2 replaced CO2 starting ~2.7 Ga, the atmosphere became less dense, resulting a cooling effect, that was steadily counteracted by an increasing luminosity sun. As well the sea levels fell as water was locked into crustal minerals and subducting slabs, and decompostion by photosynthesis. There were likely periods where geology and biology got ahead of slow increasing solar output, thus a snowball earth. Vast volcanism (traps releasing CO2) and increasing solar output once again unlocked the freezer.
Molar mass of water is 18, but I catch your drift.
But IMO CO2 had nothing to do with escape from Snowball Earth episodes.
Ouch on my part. 16 of course. Brain EtOH intoxication. I think I need another beer and just quit typing.
But hey, maybe it was H2O2. The Peroxide-oxoic!
Some great comments here from real geologists. It would be good also to hear from Bill Illis.
Please see above:
Bill Illis May 8, 2018 at 9:30 am
The only way that climate can change is through mankind’s use of fossil fuels. So before mankind started to make use of fossil fuels there was no climate change what so ever.
Humans will never be able to equal, let alone exceed, the catastrophic climate change wreaked by cyanobacteria in the Great Oxygen Catastrophe.
During that oxygenation catastrophe, recent micro-palaeontology has shown that a social grouping of bacteria formed, calling themselves “350.org”, insisting that the new bacteriogenic pollutant oxygen be stopped from exceeding 350 ppm. In the event it reached 200,000 ppm – and it wasn’t so bad – except of course for our anoxic bacterial proto-environmentalists.
The anaerobes were able to adapt and overcome by hiding out in anoxic environments.
Yes the Earth’s climate was veritable Garden of Eden before 1750 AD. Until we started burning coal and other fossil fuels.
Witness all those Biblical Old Testament stories of peaceful, placid weather, mankind at peace and love with each other, and regular rainfalls, and never a drought or flood.
Thank the Climate Gods for saving Switzerland from the Little Ice Age! The Rhone glacier, AD 1900:
http://wiki.bildungsserver.de/klimawandel/upload/thumb/Rhonegletscher_1900.jpeg/520px-Rhonegletscher_1900.jpeg
The breakthrough proof that plate tectonics is driven by liquid CH4 that is extruded from the liquid core of the planet is the anomalous fact that mid-ocean seismic activity increased starting in 1996 by on average 200% until 2015 at which time it abruptly dropped.
The standard tectonic model cannot explain a sudden worldwide increase in seismic activity and a synchronized drop mid-ocean seismic activity as the geological heating mechanisms are regional not world-wide.
The liquid CH4 mechanism’s force is alway available as that mechanism get it force to drive tectonic plate movement from the force that compresses the liquid core of the planet. When the core crystallizes that force is immediately available and the newly released CH4 immediately presses on the pressurized path to force more liquid CH4 to the surface.
What is required to explain the 200% increase in mid-ocean seismic activity, is mechanism that changes the rate of crystallization of the core of the planet.
The following is observational proof that liquid CH4 is continually being extruded from the liquid core of the planet as it crystallizes.
https://www.yahoo.com/news/500-champagne-methane-seeps-discovered-114400702.html
http://www.sciencemag.org/news/2014/08/numerous-methane-leaks-found-atlantic-sea-floor
See figure in this paper that shows the sudden increase in mid-ocean seismic activity. As the paper note the increase in mid-ocean seismic activity also correlates with recent global warming.
https://www.omicsonline.org/open-access/have-global-temperatures-reached-a-tipping-point-2573-458X-1000149.pdf
The claim that plate tectonic didn’t exist before the Neoproterozoic is simply preposterous. There are plenty of evidences of subduction-related volcanism and arc-back arc tectonic before the continent-continent collision during the Grenville Orogen and the assembly of the supercontinent Rhodinia at ca. 1 Ga. The subduction zone on the Laurentian margin prior the final collision can be traced back in time as far as 1.6 Ga. Modern-style Orogens (e.g., Himalaya-type) have been described in the Paleoproterozoic (1.8 Ga.) with the trans-China or trans-Hudson Orogens. These are also back up by a plentiful of Paleomagnetic studies. Active plate tectonic was likely operating in the Archean around 3.2 Ga.with evidences of paired-metamorphic belts which are usually a pretty convincing signature of active margin. The absence of blue schist, eclogite and ophiolite are absolutely no proof of the absence of plate tectonic in the Archean but are rather due to a somewhat different rheology of the Lithosphere because of a higher geothermal gradient.
In other words, this study is garbage.
” … and computer models suggest that the Earth didn’t cool to temperatures required for plate tectonic activity until then. …”
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Oh good grief, what a total load of speculative illogical claptrap … with computer models™.
The problem is that subductive process eats the alleged evidence of the subductive process.
Who was it recently (in a post) who included a quote warning to gather evidence BEFORE you theorise, not the other way around?
Well in precambrian geodynamics the theorised process ‘dog’, ate the geological homework.
Hence back to pointless GIGO based assertions about a geohistory digi-reality … again … speculations … all the way down.
Turn off the useless computer and get a drill core rig and do some 4D ‘truthing’ of the upper 10 km of crust that is actually still observable, and just bearly accessible (at exorbitant $$$ costs), which is still but a tiny residual fraction, of what has allegedly once digi-‘existed’ … well, in theory.
So I wonder, why do people always demand theoretical ‘explanations’, when the required material to provided one is technologically and/or economically inaccessible, and more problematically, physically doesn’t even exist anymore—if it ever did?
Why can’t they just say the honest truth, that, “we don’t know”.
No, that woud be honest. Nope, we HAVE to project untestable fictions, over the unknown or unknowable instead, because it seems the human ego and psychology can’t permit the unknown and unknowable to exist, even though it still does, and always will—we must instead pretend we ‘know’.
There is an insistence, a psychological need, to pretend away the honesty of not knowing. Why can’t we just be content with unknowables being facts, too?
Why model the unknowable, just to pointlessly project the untestable?
So we can assert a comforting fiction of expertise, it seems.
But computer models change everything! 🌈 🍰
No, outcrops and drill cores actually change everything. Anything else is useless fictional time-wasting by people who can’t deal honestly with the FACT of the unknown, and the total lack of actual expertise, sans outcrop, drill-core access to the knowable.
WX,
Here’s the deal. Clearly, the Hadean Earth didn’t have plate tectonics, since for most of it, the “crust” (not formed yet) was more or less molten.
So the question becomes, when in the Archean Eon or Paleoproterozoic Era did tectonics start up? There is not a lot of rock from that time left with which to test hypotheses. But what evidence is available suggests that sometime before 3 Ga tectonics hadn’t yet begun, but sometime around then or shortly thereafter, they had. That’s all we have to go on.
No, what is being INTERPRETED as plate tectonic crustal and mantle process began after 3gya.
You are much to quick and way too confident to accept glib assertions Felix. That’s not a good trait in a field or lab geologist trying to figure out how things really ocurred from proceses and rock assemblages that no longer form, in exponrntially decreasing older crustal blocks and their increadingly altered and reworked units.
IMO we can’t say whether plate tectonics began at 3.2 Ga or 2.8 Ga, but I favor an earlier date, in the Archean, for which evidence is mounting:
Archean Subduction: Fact or Fiction?
https://www.annualreviews.org/doi/10.1146/annurev-earth-042711-105255
Subduction drives plate tectonics and builds continental crust, and as such is one of the most important processes for shaping the present-day Earth. Here we review both theory and observations for the viability and style of Archean subduction. High Archean mantle temperature gave low mantle viscosity and affected plate strength and plate buoyancy. This resulted in slower or intermittent subduction, either of which resulted in Earth cooling profiles that fit available data. Some geological observations are interpreted as subduction related, including an “arc” signature in various igneous rocks (suggesting burial of surface material to depths of 50–100 km), structural thrust belts and dipping seismic reflectors, and high-pressure–low-temperature and low-pressure–high-temperature paired metamorphic belts. Combined geodynamical and geochemical evidence suggests that subduction operated in the Archean, although not, as often assumed, as shallow flat subduction. Instead, subduction was more episodic in nature, with more intermittent plate motion than in the Phanerozoic.
Greetings Gentlemen:
If I may interject a half-pfennig’s worth of thought, I did an undergrad thesis on PreCambrian tectonics, which, in the early 1970’s, was somewhat limited in the number of references I was able to find. If my feeble memory serves, there were some papers by a gentleman named Piper (and probably a long list of co-authors) which were syntheses of (what were called at the time) APW curves. The “APW” meant ‘apparent polar wander’. Using today’s geographic (rotational) pole position as the reference point, they reconstructed the apparent ‘wander’ of the African, Laurentian, and Amazonia cratons, with dates going back as far as 3.2 and 3.3 Ga. There were other authors who did separate reconstructions, and in some cases, the curves had remarkable similarities, and also had discrepancies (easy to understand why; same data, different boundary conditions … ).
It has always struck me that Venus and Earth have a number of similarities, and yes, a number of differences, geophysically, but Earth has an active tectonic system, and Venus (apparently) does not. Now, I am NOT an authority on the subject of Astrogeophysics, but I cannot help but wonder if the fact that Venus has a VERY slow rotation, and Earth (comparatively) has a very fast rotation, if there is something in the resultant centripetal acceleration that induced the tectonics we see today. I have not found a way to test the idea, but I keep thinking about it. The whole idea only makes sense if the early Earth was largely molten; once a thick, hard crust forms, it would be difficult to induce a system as we see today.
We also know that the Earth rotated faster in the Cambrian (about mid-Cambrian, the year had about 425 days), so extrapolating back (and applying some exponential decay as we move forward in time), it should be sensible that in Early PreCambrian time, the Earth was rotating quite fast.
So, as I said, some idle speculation, and thoughts that have permeated my grey matter for a number of decades now.
I welcome your thoughts, comments, and critiques, with all my regards to you and yours,
Vlad
Vlad,
A day lasted about 10.5 current-hours 3.0 Ga. Not precise, but close enough for government work.
Australian zircon shows that crust must have cooled at least in places by 4.4 Ga:
http://www.cbc.ca/news/technology/zircon-crystal-is-oldest-piece-of-earth-ever-found-1.2550895
Oldest continental crust had apparently formed by 3.8 Ga in Greenland, although controversial evidence from Canada says as long ago as 4.3 Ga, the dating technique of which has been questioned.
https://www.newscientist.com/article/dn14818-discovery-of-worlds-oldest-rocks-challenged-
So IMO there’s no reason why plate tectonics couldn’t have begun in some manner before 3.0 Ga. The Greenland evidence suggests possibly even as early as 3.8 Ga, since the rocks of that age are ophiolite, a chunk of oceanic crust embedded within a continent.
Current thinking about the formation of the planets holds that the gas giants formed near to the sun where most of the gas making up those planets was concentrated. The rocky planets formed farther out and migrated inward while the gas planets migrated outward. At the time of global freezing our planet would have been located much farther from the sun; no need to invoke tectonics.
We live on a thin skim wrapped around a ball of hot porridge. When you pour cold milk on it or drop things onto or in it, the skim can move around, like India, Saudi Arabia, Australia, South America, the Levant, etc. I am here to utterly shatter any notions and myths that are based “beneath the firmament.” A broader and much more scientifically robust system must therefore, without any hesitation or reservation whatsoever, include the initiators being “extra-terrestrial”, non-Kardasian, heavenly bodies in origin, such as comets, asteroids, planetesimals, planetoids and the like. The outer cooling of this ball of porridge could easily occur with Mighty Sol Invictus blowing on it, even with Sol’s hot, quarky, bosonic breath. Yes, there is most definitely visible evidence from space of continent splitting strikes even with half or portions of one crater on one continent and the other half on another continent or plate. Just put the pieces together and you see exactly where the impacts took place, mountain ranges, rivers, basins, plains and all. Highly impressive and highly logical.
Anyone need only look at a lava lake to see what I imagine the planetary surface looked like after the earth formed.
My opinion is that the water had to be present within the planetary matrix in order to allow crustal cracking and plate tectonics to form. It’s one thing to have a very thin layer of solid rock being driven by upwelling thermal movement, but when you’re talking hundreds to thousands of feet of material, something needs to lubricate that process. Water fits that role, and water had to have been present from the start. It would be unlikely for sufficient quantity to seep through surface rocks to depth that would allow plate tectonics to begin.
Slushball v. Iceball Earth:
http://blogs.ei.columbia.edu/2018/05/04/snowball-earth-frozen-solid/
Slushball isn’t all that much worse than the coldest phases of the Phanerozoic Eon Icehouses, ie Ordovician-Silurian, Carboniferous-Permian (both Paleozoic Era) and our present Paleogene-Neogene (Cenozic Era) glaciation.
http://blogs.ei.columbia.edu/wp-content/uploads/2018/05/slushball-earth-637×397.png
The Mesozic Era was generally too warm, equable and tectonically unfavorable for a full on glaciation.
Neither carbon dioxide nor plate tectonics has the power to change the climate. The evidence for the former simply isn’t there, and the evidence for the latter is countered by an inconvenient truth: the existence of the greatest “snowball Earth” in geologic history, the Huronian glaciation some 300 million years long, about 2.3 billion years ago, at a time when there was supposedly no plate tectonics. Well, the fact is that at that time, plate tectonics was in a “hot subduction” phase, which began about 3000 million years ago and gave way to an intermediate phase about 1700 million years ago. The present phase of cold subduction began about 770 million years ago, about the time of the series of 2 (perhaps 3) more recent “snowball Earths.” These events were most probably caused by proliferations of photosynthetic life forms that produced an abundance of oxygen, which, in turn, produced an abundance of ozone, which thickened the ozone shield, which then shut out a lot of Sun’s hottest, ultraviolet radiation, thereby cooling Earth’s surface and promoting the “snowball” conditions.