Was Climate Change More Extreme on Precambrian Earth vs Post-Cambrian Earth? GEO GIRL

[@tedetienne7639]

Thanks! This was one of the best Geo Girl videos I've seen! SUPER interesting! I've wondered several times about how extreme the Early Earth's conditions had been. I'd love to learn if primordial radionuclides had much effect. Potassium-40, uranium and thorium concentrations must have been much higher in the rocks and water. That radioactivity might have precluded complex life from forming, OR it might have been a potential source of energy. It's so cool to learn about all these things. Thank you so much for encouraging an interest in geology for so many people!

[@GEOGIRL]

Thank you Ted! So glad you liked this one just as much as I did! ;D I never thought about this idea until someone commented asking this question, and now I find this topic so interesting! And what a great question! I am not sure whether primordial radioisotopes like those you mention would've had that big an effect by the time that these major events occurred, I guess it would depend on their half lives, but I would need to look into it to see. I mean they would've for sure provided extra energy, potentially speeding up tectonic processes, but I have no clue the timeline on which these early isotopes were around and when they had all decayed. I will see what I find :D

[@janboreczek3045]

That's a fascinating question! Higher amount of uranium and potassium-40 could've definitely have had a significant impact. I don't thing that would be the case with thorium, since its only meaningful isotope, Th-232, has a ridiculous half life of 14 billion years, more than the age of the Earth. But I would expect that higher amount of uranium-238 would've had a significant effect (since there was twice as much of it when the Earth formed). And I reckon that uranium-235 could have had a significantly higher contribution to the radiogenic heating, since with its relatively short half life ("only" 700 million years), so there was ~30 times as much of it inside The Earth than in our time. In fact, there was so much of it ~1 billion years ago, that a natural uranium level of enrichment was enough for a self-sustained nuclear fission to occur in the uranium oxides deposits in the presence of an ordinary water as a moderator and not heavy water, which is necessary with current level of U-235 proportions in natural uranium to be an effective neutron moderator

[@stevenbaumann8692]

I appreciate the shout out! I do appreciate that you acknowledged that plate tectonics wasn't in operation on the early earth. We are still trying to figure it out. It's equivalent to the granite controversy of the 20th century.

[@LuisAldamiz]

Wasn't there convection in early Earth? I could understand that plate tectonics would be different but I feel very skeptical about lack of such thing altogether. Why?

[@stevenbaumann8692]

@@LuisAldamiz oh yeah mantle convection was definitely in operation then. We don't think mantle convection is the primary driving force. Venus has a convective mantle it doesn't have PT. PT is a real bizarre way for a planet to lose its internal heat.

[@LuisAldamiz]

@@stevenbaumann8692 - Mantle convection, difference in thickness and density between continental and oceanic plates (subduction), water lubrication and the gravitational torque of the Moon (of which I only learned recently but I find fascinanting). All them are present in principle since very early in Earth's history, except maybe continents (but the cratons probably formed in the Archaean, what is again extremely old). Why would you think there were no plate tectonics when all the ingredients were there?

[@ellenmcgowen]

@@LuisAldamiz Given the higher heat flux from the mantle, there might be an issue with slab pull? I know slab pull is an important mechanism for subduction on the modern Earth, and if the Hadean crust was very "mushy" from the higher heat perhaps it wouldn't subduct? However, there might have been other mechanisms such as impact-driven subduction?

[@LuisAldamiz]

@@ellenmcgowen - Nobody is talking about the Hadean (too unknown) but after it. I wonder what evidence there is for plate tectonics not happening. It's makes no sense to me: nothing has actually changed.

[@jamesmitchell6925]

I’m new to this channel. So glad I subscribed. Great stuff! Thanks for sharing the knowledge!

[@GEOGIRL]

Thanks so much! So glad you enjoy my content ;D

[@shadeen3604]

Great information and excellent presentation thanks geo girl

[@GEOGIRL]

Thank you! So glad you enjoyed it ;)

[@sparklytreesarecool]

THANK YOU!! Your videos are wonderful. I'm an avocational Paleontologist associated U Michigan. Learned of your videos a few days ago. Working my way through all of them. Very good!

[@GEOGIRL]

Thanks so much! I am so glad you found my channel and have been enjoying the videos ;D

[@alfredscheuer3646]

Really enjoy this channel, some good education and food for the mind helps to understand modern topics better.

[@outlier4ever]

Nailed it

[@GEOGIRL]

Thank you so much!

[@joanfregapane8683]

Very interesting episode! Thanks!

[@georgestewart9001]

this was a great video i enjoyed watching this video i learned something new watching this thankyou for a greatvideo

[@francoislacombe9071]

Something else that may have caused changes in the kind of tectonic activities happening on Earth could have been the changing amounts of radioactive elements in the core and mantle. As these elements decay, the energy they provide would diminish, and tectonic modes and intensity would vary in response.

[@capscarlett7859]

Good point. One piece of evidence to prove your point is the natural nuclear reactors about half a billion years sgo. There is a good article on this on wikipedia. Search for "natural nuclear fission reactor".

[@capscarlett7859]

Oops. 1.7 billion years ago.

[@jimmyquigley7561]

Most of the radioactive heating would have been long past by 4000My ago. Only long half-life isotopes would be left. Tidal heating from the Moon would have lasted longer.

[@wendydelisse9778]

In addition to internal radioactivity being higher in ancient times, tidal range was also higher. A good scaling approximation for tidal range is that tidal range is proportional to the inverse cube of the distance between Moon and Earth. If at some time in the ancient past the Moon was at half the modern distance from Earth, tidal range for example would have been 8 times as much as in modern times for an identical configuration of continents and sea level. Tidal range also applies to crustal movement, and even more so in past times when the crust was thinner. Tidal effects from a then closer Moon would also have added heat to the interior of Earth much more than in modern times, and would have caused much more "cyclic fatigue" in Earth crust's than in modern times.

[@desseldrayce5248]

At your convenience, would you recommend a few journal papers that talk about Hadean eon tectonics? One of the last topics I have to look more into when it comes to origin of life is whether there was land in the Hadean. You've got Russell and others in one corner saying there was no land at all, and then you've got Korenaga in the other saying nah bruh we can go coast to coast. EDIT: Oh yeah, and what about Hadean radiation levels? There's some debate about whether or not uranium levels were higher and there were more natural nuclear reactors like Oklo around, or if they came later...? And also to: STEVE! Can ya help me out? I wanna learn everything I can about the prospects of land in the Hadean! I've read a bunch on it so far but not nearly enough!

[@ellenmcgowen]

I'll second these questions! There is a debate going on in astrobiology over whether life began in ( probably Hadean) ocean geothermal vents or in geothermal pools on land. I've read one excellent book on the Hadean, T. Mark Harrison's Hadean Earth, which is based on the Hadean zircons. If anyone has a list of papers on the Hadean I would love to see it! Also, FWIW, and coming from a completely different discipline, molecular clock dates for LUCA have pushed back into early Hadean time. And a paper published in the journal Astrobiology last summer gives a recipe for catalyzing long RNA polymers under Hadean-like prebiotic conditions using basaltic glass as the template... and of course water, and nucleoside triphosphates; if this holds up it basically says that RNA world should be easy to start on any wet, habitable Earthlike planet.

[@desseldrayce5248]

@@ellenmcgowen Harrison's "Hadean Earth" is a good book, and it piles on another question! Most of the people I've read who agree that there was probably land think the first terrestrial crust was mafic, but in that book Harrison says it was felsic. Benner's paper on prebiotic rock glass is also good! Imnsho, I think both sides of the fields/pools vs. vents debate are like the fable of the blind men touching different parts of the elephant. The people who support vents often just think of marine origins, and the land advocates go for freshwater. But what about continentally based vent systems? Impact-induced lakes with vent chimneys on the lake floor! I think this hybrid between the two amounts to the best theory, and Barge has a recent paper on similar sites, like the Prony vent at New Caledonia in Spain!

[@ellenmcgowen]

@@desseldrayce5248 If I understand correctly, a mafic crust could subduct, leaving nothing for modern geologists to examine, while a felsic crust can float on the magma and build continental cratons, for which we have no Hadean-age evidence. But what I don't understand is the role that bombardment might have played in Hadean and early Archean tectonics and also the effects of the greater heat dissipation and mantle convection.

[@desseldrayce5248]

@@ellenmcgowen Yes, I'm right there, too, especially learning more about your point about mantle convection; I've listened to a few lectures where the suggestion was that more rapid mantle convection could facilitate non-modern style plate tectonics, but I dunno the deets. You were looking for some papers on the Hadean, here's a short list that was part of a bibliography I sent to someone recently. "Paleomineralogy of the Hadean Eon: A Preliminary Species List" - Hazen (2013) "The Paleomineralogy of the Hadean Eon Revisited" - Morrison (2018) "A Wet Heterogeneous Mantle Creates a Habitable World in the Hadean" - Korenaga (2022) "Life in a Carbon Dioxide World" - Preiner (2021) "Evidence for Early Life in Earth's Oldest Hydrothermal Vent Precipitates" - Dodd (2017) (Compiler's Note: A subsequent publication has questioned whether or not the fossils are as old as the vent system. But both studies concur that the site is 3.7-4.2 Ga.) "The Hadean Crust: Evidence from >4 Ga Zircons" - Harrison (2009) "Nitrogen Oxides in Early Earth's Atmosphere as Electron Acceptors for Life's Emergence" - Wong (2017) "Composition of the Primordial Ocean Just After Its Formation" - Ueda (2021) "Primordial Ocean Chemistry and Its Compatability with an RNA World" - Kua (2011) "Marine Phosphate Availability and the Chemical Origins of Life on Earth" - Brady (2022) The Russell vs. Korenaga debate can be found in Russell's, "The Water Problem (Sic)" and Korenaga's, "Was There Land in the Hadean?"

[@ellenmcgowen]

@@desseldrayce5248 Thank you for that list!

[@PraiseDog]

Do you do all the work yourself producing these weekly videos? How much time do you have to spend. Just curious. I appreciate your presentation, you provide a lot of information and do so both verbally and in your outlines which facilitates memorization. I like the pictures as well. It seems like a lot of work to me.

[@barbaradurfee645]

The best way to learn is to teach 😊

[@a.randomjack6661]

​@@barbaradurfee645 Douglas Adams exp;ains that very nicely in his novel "Dirk Gently-s Holistic Detective Agency" I left the full title to make the search easier on youtube as this is the audiobook version read by the author. I read and viewed almost everythmg about him, a really interesting author. Rachel would enjoy if she wasn't so busy

[@GEOGIRL]

It is a lot of work haha, I don't do it every week though. I actually do the research for about 3 to 4 videos at a time and then film them all in a row and schedule them to go out weekly so that I can take breaks from youtube to work on my research. Thankfully, I can have a similar schedule for my research. I typically work on writing proposals and manuscripts in batches and I am working in several groups (right now I am working on 3 manuscripts: 1 for my phd research with my advisor, 1 with a group of scientists at the woods hole oceanographic institution, and 1 with a group at nasa), so I work really hard on writing for all of the manuscripts for a few weeks, then send them all out to their respective groups for further editting and input, then while I wait for my co-authors to get back to me, I get ahead on youtube! So it's just a constant back and forth haha. Fortunately, youtube is my 'fun time', it is a lot of research and work, but I really enjoy it ;)

[@a.randomjack6661]

@@GEOGIRL Woods Hole.... Jennifer Francis comes to mind. I know she did, still does? work there. She's ne of my favorite scientist btw, I watched many of her videos. Take care 🖖

[@PraiseDog]

​@@GEOGIRL Thanks, highly admirable.

[@dangallagher8034]

Fantastic info/presentation as is usual. Sincere thanks.

[@GEOGIRL]

Thanks so much! ;)

[@notabitgreen8773]

Thanks!

[@GEOGIRL]

Thanks so much! So glad you enjoyed it :)

[@Beastclub679]

Always love your video's...❤❤

[@ArbitraryConstant]

This is the first time I have ever heard of different tectonic styles and would be fascinated to hear more about it. I've been trying to find resources online and it's quite difficult without institutional journal access. I would definitely watch a video on this if you ended up making one.

[@ianhorsham7751]

Thanks for another fascinating video! They always get me thinking. The way plate tectonics has changed is expecially interesting. After the interglacial period we currently in finishes could we expect to see similar patterns?

[@johnabbe]

Pretty sure our interglacial is over, we are heading out of that rhythm/equilibrium at a rapid pace. But I love the question of what a 'next' tectonic style might be! We are also learning interesting stuff about complex structures in the mantle.

[@RyanEglitis]

One thing to note about the current era is the rate of change compared to earlier warming and cooling events. The modern era has some of the greatest rates of change that we have seen, even if they aren't wild outliers as of yet in terms of actual surface temperatures.

[@GEOGIRL]

Great point!

[@klauskarpfen9039]

I often wonder how extreme volcanism may have been during the early days on earth compared to today. This brings me back to diamond formation: I think I've seen "somewhere" (cannot find anymore where) that diamonds (near surface diamonds) were only formed during very few and discreet time periods very much in the past, when magma has welled up from deep inside the mantle. Today's volcanism is, my guess, much "shallower" and will not bring us any more new diamond deposits... . Maybe another video idea?

[@GEOGIRL]

That is actually a great future video idea! I have some videos that in certain parts discuss the difference between early earth volcanism and modern volcanism (mostly in my Io videos), but I don't yet have one purely discussing that topic, I think that's a great idea, thanks! ;D

[@stevenbaumann8692]

Volcanism is probably more active today than in the Proterozoic. We actually had a warmer lithosphere and more ductile deformation. The Hadean and Archean are different stories.

[@donaldbrizzolara7720]

Rachel: You come up with such interesting and thought provoking topics. I guess I lean towards an extreme early earth but still believe that the full story hasn’t been dealt out yet due to the illusion of time. I know…I’ve become wishy washy in my old age. As always, a beautiful summary. I have another thought and suggestion…I’ve been thinking about what initially drove me towards geology. What enticed me about it? I think a large factor was the element of field work (plus minimal math requirements😆!). The ability to work outdoors and attempt to unravel some of the earth’s mysteries to me was irresistible. I think many of us felt that way. Now this may not be applicable to your channel but I would think a video introduction to the nature of geologic field work would be an interesting topic for the general public. I don’t believe that you have addressed this subject in your many videos, but it really is part of the groundwork basic to a geologist’s education. How is data collected and what basic instruments or tools are used? How is an area mapped? What is stratigraphic section and how is it measured? How are contacts and faults delineated? How is structural data collected, etc…etc? It’s a big and fascinating topic. For the past couple of years I’ve even considered tackling the subject myself with a series of “a day in the life of” KZbin videos…but, truly, you would be the very best teacher. At any rate…just a thought…and an idea for future works.

[@barbaradurfee645]

Excellent suggestion!

[@barbaradurfee645]

Don is among a group of very experienced field geologists who have done some of the most challenging mapping and interpretation of remote areas of the world. I’m not a field geologist but I hold them in awe because the ones I have known seem to be a combination of super fit, brave, curious, resilient and great story tellers. They are the kind of people who like to cross crevasses and walk on erupting volcanoes, and scale steep snake infested parts of Borneo etc. Guys (sorry it mostly guys) who mapped in war torn regions, dangerous terrain, dangerous animals, etc. it would be smart to try to capture their stories, and lessons learned. Field work is always necessary as technology and ideas evolve and as the planet changes.

[@stevenbaumann8692]

To future geologists out there. When plate tectonics started is the biggest unanswered geology question of the 21st century. Study the Archean in North America.

[@wendydelisse9778]

There is a second cause of oxygen. That second cause is ultraviolet light, which is also a cause of nitrogen, both on Earth and on Venus. In the presence of ultraviolet light, water breaks down into hydrogen and oxygen. A small fraction of the hydrogen leaks into outer space before it can recombine with oxygen in order to re-form water, leaving some excess oxygen behind. In the presence of ultraviolet light, primordial ammonia breaks down into hydrogen and nitrogen. A large fraction of the hydrogen leaks into outer space before it can recombine with nitrogen in order to re-form ammonia, leaving some excess nitrogen behind. In terms of molecular breakdown of water and ammonia, ultraviolet light comes from three main sources, sunlight and lightning and meteorite strikes. On the planet Venus, modern partial pressure of both nitrogen and oxygen are higher than on Earth, which makes sense in a lot of ways. Sunlight hits the planet Venus harder than on Earth, and meteorites have between 15 and 20 percent more speed from solar gravity on Venus than on Earth, and so hit harder, driving created hydrogen higher on Venus than on Earth, to an altitude on Venus where hydrogen recombining with nitrogen or oxygen becomes difficult due to lower partial pressure of nitrogen and oxygen at high altitude. Also, the lower escape velocity from Venus in comparison to Earth makes the escape of separated hydrogen into outer space easier. The result is that the planet Venus has very little water in comparison to Earth, and a higher partial surface pressure of oxygen than on Earth. Short version: In a process much more apparent on Venus than on Earth, ultraviolet light is a second cause of atmospheric oxygen, and in addition ultraviolet light was a major cause of atmospheric nitrogen. Potentially in the distant future of Earth, there could eventually be an overabundance of oxygen, and a scarcity of water, as has already happened on the planet Venus.

[@DrSmooth2000]

Recognized your style part way in ✊

[@ianhorsham7751]

I wonder if the length of the days increasing could have an impact?

[@الحمدلله-ع1ب3ث]

Thanks for the translation 😊.

[@davidhoward4715]

As usual, this is clear, concise, interesting and informative.

[@liamredmill9134]

Good point,and coverage of a popular curiosity

[@Beastclub679]

Very nice video.. geo girl...😁😁✨✨

[@pawned79]

Does anyone else think of crème brûlée whenever Rachel talks about plate tectonics?

[@georgefspicka5483]

Hi there Geo-Girl, I haven’t gone through your presentation yet, but I’m going to say Precambrian, even though both have their moments. One reason is because of the Great Oxygenation Event, which changed the oceans and atmosphere completely, and almost caused the early anaerobic ways of life to go extinct. The other is “Snowball” Earth. Either way, I know I’m going to enjoy this :)

[@creakyprimate]

Great vid Rachel.

[@GEOGIRL]

Thank you!

[@homieslice1996]

This is a great video! I learned of climate change for some years, but geology and geography are important to understand long and short term climatic changes. Icehouse and greenhouse events, while we live towards the end of an icehouse event, would be important to adapt to and balance out the effects of industrial, human-related causes have had with their lack of balance and capitalistic motivations that prevent us from actually adapting to and mitigating to our best ability the human intensified climate change. Long and short: climate has changed naturally, but human activity since industry has also played a role in intensifying and speeding up the already natural climate change.

[@anaryl]

We love you geo girl! Yewwww ❤

[@robbabcock_]

Great stuff!

[@itsjustkai8524]

Please do a video(s) on different type of ore deposits

[@itsjustkai8524]

As well as more videos on structural geology (folds/faults etc)

[@1969kodiakbear]

Earth's secretion. By the way, I have difficulty communicating because I had a stroke in Broca’s area, the part of the brain that controls speech. 2/8/2021 but I lived again. (My wife helped me compose this.)

[@ellenmcgowen]

This excellent video sent me off to the Dewey et al. paper, where I immediately had trouble with their reconstruction of the Hadean as a dry planet. They think all Earth's water was delivered during Late Heavy Bombardment, which is probably inconsistent with asteroid and comet D/H ratios. One idea in planetary science is that most of Earth's water came from the local solar nebula, and would have been present as an ocean from at least ~4.4 Gya. The early Earth is generally seen as (mostly) a water world. This is also consistent with Hadean zircon grain isotope studies and the view that they were produced in pillow lavas. But Dewey et al. explain the zircons as having formed in small pools on an otherwise dry Hadean Earth. There seems to be disagreement among geologists over whether there was continental crust formation in the Hadean. Dewey et al. claim there was not, because there are no traces of it left today. Other authors say that the Hadean produced substantial continental crust; it's presumed to have been under water until the late Archean, by which time subduction had lowered the depth of the oceans exposing more continental crust. Hadean crust formation is also invoked as a way to remove CO2 from the atmosphere. As a non-geologist, I don't know what to make of Dewey et al.'s argument that we should have granitic crustal rock left from the Hadean if there ever was any crust produced. I understand that the presence of a lot of water in the Hadean would have helped subduction and continent-building. But I don't understand the destruction processes for early crustal material. Mantle convection should have been very vigorous in the Hadean; maybe all the early crust was subducted. (Or is that impossible because it is too buoyant?) Anyway -- a fascinating video that gives me more reading matter...

[@barbaradurfee645]

Thanks for your summary!

[@wendydelisse9778]

Astronauts with geological training on the Moon found very little of the Moon's original crust. On the Moon, after the Moon had been in existence for a hundred million years, meteorites would have most likely had more destructive effect on early crustal material than lava flows from internal heat. Put together the mixing effect of Earth's flows of hot materials from the interior, and meteorite impacts on Earth like on the Moon, and erosion effects from wind and water on Earth, any given kilogram of solid surface material on Earth a hundred million years after the formation of the Moon would have had much less of a chance than on the Moon to survive somewhat intact until modern times.

[@stevenbaumann8692]

We don't know if the Hadean was dry or not but it probably was at least for the first half. Also, we aren't sure anymore that the water was mostly delivered by meteorites. At least not some. See Newcomb.

[@wendydelisse9778]

Part of the debate between dry versus not dry might have to do with the critical temperature and pressure of a solution of water. Pure water has a critical temperature of 374 degrees Celsius (705 degrees Fahrenheit), and a critical pressure of 22 million pascals, which is roughly the pressure of seawater at a depth of 2200 meters. A liquid a little bit lower in temperature and pressure has greatly diminished surface tension. A liquid a little bit higher in temperature and pressure has zero surface tension, so in a way the difference between liquid and gas has then disappeared, but electric power plant operators report that departure from nucleate boiling (DNB) can still occur, so in another way the difference between liquid and gas has not gone away completely with a slightly supercritical pressure and temperature. For corrosion prevention reasons, many electric power plant operators use an ammoniacal solution consisting of about 1/4 of ammonia by weight in their boilers. Ancient earth likely had an at least somewhat ammoniacal atmosphere in the earliest part of the Hadean Eon, changing somewhat where the point of critical temperature and pressure was for water precipitating in the atmosphere on ancient Earth. Short version: There were times on ancient Earth when by the time precipitating water got to the ground, it might have been neither liquid or gas, but something in between, due to a combination of higher pressure and higher temperature. The technical name for that something in between is a "supercritical fluid".

[@barbaradurfee645]

@@wendydelisse9778 new knowledge for me, thanks!!

[@georgefspicka5483]

Ok, I'm through. I especially like the part about the different ways plate tectonics worked, and how it seeming relates to other events.

[@barbaradurfee645]

Me too!

[@Beastclub679]

So beautiful look...geo girl ✨✨⚡😁😁

[@johnrichardson7629]

At first I wasn't sure what you meant by time illusion. But I've often amused myself by contemplating how ancient, say, the rock paintings in France already were when, say, the first cities of Sumer were founded. Or even just contemplating that it's been about as long since I graduated high school as from such "ancient history" as the start of WW I to the when I graduated. So, when I heard the time separation between the two snow ball earth events (I never knew there was a second one!), I was kinda primed to raise the time illusion argument myself and figured out what you must have meant. Time illusions are seriously problematic. Even if you go back all the way to the earliest hominids, our clade has been around for only a small fraction of the time since animals first arose. And our species have occupied only a small fraction of the time since those earliest hominids arose. Ditto the time since the earliest Neolithic compared to our species history. Yet some people speak as though cultural institutions that have existed for only a sliver of the total time since the rise of agriculture have stood the test of time and are all but eternal in their prospects. Nuh uh. They may have passed a pop quiz or two but bigger exams are no doubt still coming!

[@barbaradurfee645]

Good point

[@thhseeking]

Another way of explaining I've heard was that Cleopatra was closer to us than she was to the Pyramids.

[@tohellorbarbados7119]

@@thhseeking Although not geographically...

[@LuisAldamiz]

@@tohellorbarbados7119 - Well, to me she was when she visited Rome...

[@just_kos99]

I'm surprised you didn't mention komatiite, since the Earth's too cool now to create it.

[@GEOGIRL]

Haha yea that's true, but it wasn't like an 'event', it was just a time on earth when ultramafic volcanism could occur before it was too fractionated to continue excreting ultramafic lava at the surface. That is actually a great idea for a future video though! Maybe one about the state of early earth vs modern earth (rather than events). :D Thanks for the comment!

[@BMrider75]

@@GEOGIRL while not an 'event' , doesn't the production of Komatiites , with their high temperatures, speak of more extreme conditions than today? Yes, do a video on this phenomenon. Seeing where lava has cut its own trench through/into the bedrock was amazing when I worked in a nickel mine (sphalerite deposit).

[@stevenbaumann8692]

Earth also doesn't produce banded iron formation anymore

[@jimthain8777]

I have a question, that may be important, or a big nothing. I have heard that scientists can distinguish between ancient CO2 and modern CO2 (different isotopes I believe). This leads to my question. Could different isotopes of Carbon act differently in the atmosphere, or will they act the same regardless of isotope? This probably isn't as interesting a question as the one that inspired this video, but it is one that's bugged me for a while, and I haven't had access to anyone I thought could answer it. Then I saw this video, and thought you might have, or be able to access the answer. Thanks for doing these kinds of videos, they are super interesting.

[@GEOGIRL]

That is a great question! They actually act the exact same when it comes to their greenhouse warming effect. Chemically, structurally, and reactivity wise CO2 with different C isotopes are exactly the same. The only difference between CO2 molecules with different C isotopes is a slight mass difference because of the difference in the number of neutrons. I actually have a video discussing stable & radioactive isotopes and I discuss C isotopes and how they work a bit more in that if you want to check it out ;) -> kzbin.info/www/bejne/roXJdJV6adh-gac

[@RobertMStahl]

When did the ozone form? Also, did not the Krebs cycle for 32 ATP per cycle come a long time after the autumn colors of a much weaker photosynthetic cycle? I like James MacAllister's piece, "Earth Shaking Paradigm Shift: Biological Relativity," geology being mightily significant.

[@stevenbaumann8692]

We think the first ozone was about 600 million years ago. But we had (and still do) photosynthetic stromatolites extending back 3500 million years in the oceans and lakes.

[@terenzo50]

Other extremes would be the number of lightning strikes (from twice as many to ten times as many as today contributing to Miller-Urey life molecules which don't take very long to get going not to mention how continued strikes contribute to diversity by breaking apart and fusing together any molecules in the vicinity) and the amount of volcanism both above ground and underwater which would have greatly increased land mass and tectonic imbalances in turn contributing to their shifting thisaway and thataway. Oxidation events were occurring on land (plants) and water (Prochlorococcus marinus) so basically everywhere at once if (and that's a pretty big if) both plants and Prochlorococcus developed at roughly the same time. I've no idea if anyone is studying the paleo-origins of Prochlorococcus. You might ask Penny Chisholm at MIT.

[@stevenbaumann8692]

Lightning strikes we're probably more frequent, but we can't know for sure. But our atmosphere was more like Venus then. Not like his experiments. We know this because of the rocks. In his defense, we had no clue then.

[@hannalindstrand3156]

Super cool

[@johnbaker1256]

More complex systems are more strongly buffered.

[@GEOGIRL]

Yes, that actually sums up the video perfectly, thanks!

[@johnbaker1256]

@@GEOGIRL Works at all levels, from test tube to planet.

[@DavidFMayerPhD]

The migration of the Earth due to sunlight, loss of solar mass, and thrust by solar wind against the magnetic field IS CONTINUING today at a reduced rate. It will never stop.

[@bryandoehler8962]

True, but the increase of the sun's luminosity is making its habitability zone move outward at a faster rate than the earth's orbit is. In a few billion years inner edge of the sun's habitability zone will be beyond earth's orbit.

[@DavidFMayerPhD]

@@bryandoehler8962 Yes, true. But the migration of the Earth's orbit has helped to delay the effects of the increase in luminosity by billions of years.

[@terenzo50]

Oops! Also more Chicxulub events! So: more Lightning, more Volcanism and more Chicxulubs! It's a wonder the poor old planet is still here! Well, we'll finish it off...

[@davidwilkie9551]

One imagines, depending on how much the formation was organised by a continuous tidal pulse accumulation, which is most likely in a dust cloud, and/or there are lumps and random conglomerations of the three meteor type compositions we think we know about now, and after the first hot Spheroidal formation, hot hot?, and how intermittent was the beginning of Convection Cells, Plumes etc?, and that is only one narrow Materialistic POV that is intensely interesting in itself, but "there are more things in space and time than are written in the geological-cosmological records", (not Shakespearean but "all the world's a stage".. of continuous creation cause-effect)

[@davidmrofka]

Appreciate the videos! I've been assigning them as as activities in both my Climate Change class and Earth Science classes. Great for students to see that science is carried out not just by old white dudes (me) so they have been a great addition to spot lighting the diverse group of scientists studying climate change . My only alteration is that I would have placed a "hypothetical" or "possible" in front of Snowball Earth events :)

[@johnvoelker4345]

at 3:10 you say ‘...photosynthesizing organisms create oxygen by splitting water using CO₂ and light energy’ actually, ½ of the O₂ comes from H₂O and ½ comes from CO₂ this is evident from the chemical equation for photosynthesis: 6H₂O + 6CO₂ => C₆H₁₂O₆ + 6O₂ as you can see, 6 O₂ molecules are produced but only 6 H₂O molecules are inputed those 6 H₂O molecules contain only 6 O atoms but the 6 O₂ molecules produced need 12 O atoms so, the other 6 have to come from CO₂

[@wlhgmk]

There is a very convincing argument that this present Interglacial period is remarkably stable compared to other interglacial periods within the Ice age that we are in the middle of right now and this stability is attributed to us and our actions starting some 7000 years ago or so. It is explored in the book Plows Plagues and Petroleum by Ruddiman. A fascinating read. He hypothesizes that from way back when, we slowed down the slide into the next glacial period but the black death and the demise of the people of the Americas due to European disease allowed the growth of trees to really take off and the glacial period started (on the high lands of Baffin Island). Then the industrial revolution began and the ice retreated.

[@johnvoelker4345]

at 3:49 you say ‘500 million years ago, at the beginning of the Precambrian...’ you mean Cambrian, not Precambrian 542 million years ago is the end of the Precambrian, not the beginning

[@GEOGIRL]

Yep, I meant to say Cambrian! My bad, thanks for catching that! ;)

[@johnvoelker4345]

@@GEOGIRL actually, that’s still wrong 500 million years ago was the end of the Cambrian period the Cambrian period began 542 million years ago and lasted 53 million years so, 500 million years ago would’ve been the last 15 million years of a 53 million year long period so, the end

[@nicholasmaude6906]

I'd say that most, if not all, of the Precambrian would be uninhabitable and unsurvivable for Humans without specialist life-support equipment and a LOT of supplies.

[@juanmigueloctaviano6736]

You bring up a good point about whether those extreme events were just an illusion of time. It's like, did they really happen or are we just looking at things through a different lens?

[@GEOGIRL]

Well they definitely really happened (I mean there's certainly room for alterations of our current reconstructions, but some version of a snowball earth event and goe happened around 2.4 billion years ago and same with 700-600 million yrs ago), it's just a matter of whether this will happen again in a time frame that has about the same periodicity as these previous events, or if things will never be that extreme on earth again. I feel like the answer is yes and no haha. I think that we will never have another snowball earth or oxygenation event again because oxygen concentrations in the atmosphere will never go back to the levels of increase they underwent in the Precambrian (unless all oxygen respiring organisms were to go extinct and only photosynthesizers remained like on early Earth, which I think is extremely unlikely). But I also think it's possible for things to get that extreme again, just maybe for different reasons (like instead of oxygen rise, maybe astronomical changes like the sun's intensity or Earth's orbit, etc.). Anyway, I am rambling now, but it is just such an interesting topic to me haha :D

[@liviusiancu1319]

I'm not sure the total mass of complex animals ever got high enough to directly offset C storage during the Phanerozoic....the development of the first soils and arrival of heterotrophic soil microorganisms might have though... and today, belowground heterotrophic respiration is the process responsible for the 2nd largest annual transfer of C to the atmosphere

[@AlecMuller]

If you categorize feedback mechanisms as *geologic, biological, or technological*, it's clear that biology & technology can have the same global impact in orders of magnitude less time, so it makes sense that they're dominating in terms of current change. Hopefully the negative feedback mechanisms win out, and the Great Filter is behind us, not in front of us.

[@quantumcat7673]

Thank you for your very informative video. Perhaps methane in the paleoproterozoic atmosphere, destroyed by oxygen, contributed appreciably to the cooling of the Earth during the Huronian.

[@peterdore2572]

Pretty Extreme Video!

[@liamredmill9134]

There are variations to take into account like,a possibly much smaller earth size with possibly the same super powerfull magnetic drive(driving poles further around the earth,with possibly more hydrogen/oxygen leaving earth or being trapped on a smaller earth,,,,that was nearer or further to the moon and suns lower but maybe also kaotic output.sorry and thankyou for being a great teacher/narrator for the young,unlike my old self

[@GEOGIRL]

Thanks for the input! Those are all great ideas, I will have to look into the effect those factors and the ones you mention in your other comment may have had on early Earth, I am super curious now ;D Maybe this research will lead me to a future video idea!

[@stevenbaumann8692]

The earth was at its present mass from at least 4.5 billion years ago. Yes there have been impacts and stuff since then, but they are insignificant related to the mass.

[@GEOGIRL]

@@stevenbaumann8692 Hey Steven! Thanks so much for putting all the feedback down here in the comments, not only for my benefit but all the other commenters as well! You are the best ;D

[@stevenbaumann8692]

@@GEOGIRL No problem. I know what it is like to try to figure it all out.

[@yancgc5098]

The NOE didn’t really take oxygen levels that close to modern levels. Atmospheric oxygen was still around 10-11% in the Cambrian period, with an increase happening in Late Ordovician, in the Silurian-Devonian Terrestrial Revolution, and in the Late Devonian. All of these increases led to Early Carboniferous having 20-21% oxygen and then reaching 35% in the Late Carboniferous. This honestly makes more sense to me than oxygen levels going from 3% to 20% from the NOE alone.

[@yancgc5098]

Also plants don’t solely take in CO2 and let out O2 through photosynthesis, they also sometimes do photorespiration as well. So animals aren’t the only ones contributing to the respiration part of the photosynthesis-respiration balance.

[@GEOGIRL]

Yes, but early photosynthesizing cyanobacteria, which caused the GOE, did not respire oxygen at night like plants do. They can either remain dormant until sunlight is back or do anaerobic respiration such as nitrogen fixation. And yep, I talk about the rise of oxygen in other videos more precisely and in those I mention the caveats of the fluctuations throughout the Paleozoic era, but in videos where I am not discussing oxygen levels in detail like this one it is sometimes easier just to say it rose some in the GOE and then all the way in the NOE haha, but you're right I should've been more clear on that, thanks for mentioning this! ;)

[@yancgc5098]

@@GEOGIRL Thanks for the response, I always enjoy talking about topics like this. High quality content from you as always.

[@الحمدلله-ع1ب3ث]

What is the name of your university and what is your major

[@الحمدلله-ع1ب3ث]

We need a video about mountain building movements

[@GEOGIRL]

I am a phd student at the University of Texas at El Paso! But I am hoping to graduate this year ;D

[@الحمدلله-ع1ب3ث]

@@GEOGIRL good luck 🤞,you are a hardworking person.

[@liamredmill9134]

Also Carrington currents from the sun's umbilical cord might have encountered a denser ,smaller earth

[@BMrider75]

Smaller Earth ? ! Same mass but denser, or same Average density but less mass? Sounds kooky. I'm pretty certain the expanding Earth hypothesis has been roundly rejected decades ago......

[@stevenbaumann8692]

The earth wasn't smaller and more dense in the past. That hypothesis was discarded almost 100 years ago. Actually an early earth was warmer, if anything it was slightly larger...although it has always been essentially the same size and density for the past 4.5 billion years.

[@Beastclub679]

How are you geo girl... what is going in Texas..🙂🙂??!!

[@GEOGIRL]

Wow thanks for all the engagement haha ;D And texas is good haha, not much is new with me though. I am still working on my dissertation :)

[@carltuckerson7718]

So busy. Catching up on the videos. Too many kids in this house…

[@GEOGIRL]

Haha no problem, I hope you enjoy the recent uploads ;)

[@TheDanEdwards]

Snowball Earth... but you show the current North American continent!! I understand the need for easy graphics, but I think it not only is more accurate but also more informative (about how the Earth surface has changed) to use a super-continent reconstruction.

[@GEOGIRL]

Hahaha I know I hated that I had to do that as well, but I ha to do it to line it up with modern earth on the thumbnail. Without it lining up that way it looked really weird 🤣 I am sorry, I normally try to include more accurate reconstructions.

[@barbaradurfee645]

@@GEOGIRL yeah Rachel, in your abundant free time while being an underpaid research assistant grad student why don’t you draft some new graphics for you free KZbin videos?❤❤❤

[@jjsmallpiece9234]

There were more wild cats around, so the world was more extreme. Today's tame moggies have it far too easy

[@DrSmooth2000]

Cenozoic NorthAm has the CatGap but how does that fit into Theory?

[@jjsmallpiece9234]

@@DrSmooth2000 Have you ever had a sense of humour?

[@DrSmooth2000]

@@jjsmallpiece9234 you just experienced it 😼

[@jjsmallpiece9234]

@@DrSmooth2000 Clearly you failed

[@DrSmooth2000]

@@jjsmallpiece9234 would you describe your attitude as in the GeoGirl Spirit?

[@rursus8354]

Yes, that makes sense. Higher life must be the reason.

[@legendre007]

And so we can deem it more extreme, it would seem? 😮🌐

[@الحمدلله-ع1ب3ث]

Are you still studying in the university?

[@richpelto248]

I wish you were sitting next to me in my G2 class at UMD

[@I.amthatrealJuan]

Sorry to say this, but the words oxidation and oxygenation shouldn't have been used interchangeably. That's all.

[@GEOGIRL]

Well I would agree with regards to general oxidation because many molecules can act as oxidants, not just oxygen. However, with regards to these events, the term oxidation works just as well as oxygenation because while oxygenation refers to the increase in molecular oxygen concentration, this directly caused major oxidation of many reduced compounds on early Earth, especially during the first event, before which earth's surface was dominated by reduced compounds. That is why I tend to refer to the GOE (the first oxygen rise) as the great oxidation event and the second one (the NOE) as the neoproterozoic oxygenation event, because by the second event there wasn't quite as much oxidation given that things had already been partially oxidized by then. Anyway, I do not disagree with you, I should've been more clear with the meaning of those two terms not being the same, but I do think they can both be used for the goe :)

[@TrentSpriggs-n7c]

Are you working on a combined algorithm to let us know how much renewable energy, afforestation, and carbon capture would be needed? Global energy systems are due for an upgrade. Something like that would sure come in handy, say by 2030. You seem to be someone who should be on that team.

[@GEOGIRL]

Well my research is focused more on paleoclimate than modern climate, but I can assure you I know and have worked with modern climate scientists before who are working on things like that, and they have much more brilliant brains than myself, so don't worry, the best are on it (I think the bigger worry is whether the general public will listen to their findings lol) ;)

[@TrentSpriggs-n7c]

@@GEOGIRL I would tend to agree on the public perception aspect. I would however, foresee complex modeling sets, that would need a long span view, longitudinal in fact, to ensure accuracy and efficacy. Trends would be more important than detail, at higher levels, as anything run would be somewhat incomplete, or be beset with the unexpected. Quality assurance is a team sport. At any rate, I will continue to bone up on your area of expertise. You are doing a first rate job.

[@RobertMStahl]

Interruption is a real factor. I take note of Antonio Zamora's presentations on the Carolina Bays, a series? Also, if you consider an accelerating expanding universe obviously driven by the current density function that is an electron's radiative relation to hydrino, totally diminutive hydrogen, follow the Great Circle and finite structure toward particle annihilation, 10 times TNT, too, see Mental Boost 2 4 data on 9-11. Hydrino is lightening clapping, 9-11, Hunga Tonga-Hunga Ha‘apai, Nashville on Christmas, Georgia Guidestones, and halo Burton studies, et alia. O-Mission is the worst sin. Don't be Pro-NU Clear. Dark matter is antecedent, blacklight on the Raman spectrum. Stay tuned. Quick is quick. Have you seen James MacAllister's piece on biological relativity, follow thru to Scott F. Gilbert, this autopoietic principle.

[@charlesbrightman4237]

Consider the following concerning climate change: (which nobody talks about but I believe to be really true): 1. Modern science claims all matter is made up of quarks, electrons and interacting energy. Quarks and electrons are considered charged particles, each with their respective magnetic field with them. 2. Via QED (Quantum Electro Dynamics, whereby electromagnetism interacts with electrons in atoms and molecules) and QCD (Quantum Chromo Dynamics, whereby electromagnetism interacts with the nucleus of atoms), electromagnetism ('em') of course interacts with matter. 3. Agitated matter is considered 'heat'. 4. While not all matter is considered magnetic, all matter can be affected by magnetism. 5. Humans have been dumping 'em' of various energy frequencies into the atmosphere all the way up to outer space and back (continuously, day and night, weekends and holidays included) for decades now. Just like a push of a swing, it adds to the movement already there. 6. Anybody willing to give up all your electromagnetic driven devices? Probably not many. Hence expect climate to change. And just like CO2, we did it to ourselves. 7. Of course also, Nature is going to do what Nature does and does not care about us or our agendas, but that is another part of climate change. (Earth's magnetism changes).

[@petefluffy7420]

Please define what you mean by extreme. You used the term climate change, let's assume that the operative word is change. Is extreme, in your definition, fast climate change, or is it slow climate change? Focussing on the word climate, I would presume than extreme is the greatest shift from before to after.

[@GEOGIRL]

That's a great question! In this video, I tried to only use it relatively, rather than outright. So what I mean by 'more' extreme is relative to Phanerozoic (post-500 million yr ago) events. For example, global snowball earth events were only observed before the Phanerozoic, and same with the great and neoproterozoic oxygen events, this degree of oxygen rise was never again seen in the Phanerozoic. There were periods of cooling and oxygen rise in the Phanerozoic, just none that reached the magnitude of the Precambrian, so again, it's just relative here. The use of terms like fast or slow is also very difficult because for a geologist like myself, when I say the word fast, I am still typically talking millions of years haha. I think with regards to geologic time, all of these 'extreme' events began quickly. If they were gradual on a geologic timescale, they would never have spread globally and gotten so 'extreme'. However, that being said, the change that led to the snowball earth events, for example, was still likely 'slow' relative to modern climate change, because modern climate change is more rapid due to humans expiditing geologic processes. So in summary, it's all relative ;) haha I hope that somewhat answers your question!

[@matthewdolan5831]

Highest data per sec on the web...

[@billkallas1762]

Things will also become nasty in another 600 million years. Things will be going downhill after that. Plants die because of .005% CO2 in the atmosphere. O2 begins to crash.

[@TheDanEdwards]

"Things will be going downhill after that. Plants die because of .005% CO2 in the atmosphere". - given that photosynthesis arose in what was already a hostile environment, it is unlikely that plants will disappear until the very end of surface life.

[@billkallas1762]

@@TheDanEdwards Plants can't survive without CO2, just like Animals can't survive without O2. The accepted theory is that CO2 levels are going to slowly decrease over the next 600 million years. Currently, the level is at .04%. In 200 million years, the level will drop to .02%, and by 400 million years, to .01%. The average temperature of the Earth, 600 million years from now will also rise to 30 degree C, because of the greater output of the sun.

[@DrSmooth2000]

​@@billkallas1762this does not factor our carbon reclamation?

[@JKTCGMV13]

🌏 ❤

[@unclefatbloke687]

As you are talking about Climate Change, how about also doing a period of human history of say 10,000 years ago until now, rather than millions of years ago? So we can see what climate was experienced relative to today.

[@GEOGIRL]

My specific expertise and field of research is more so in paleoclimate and paleoceanography of very ancient Earth, but I can certainly look into more recent climate change and see if I can find enough info for a future video! ;) Thanks for the suggestion

[@wendydelisse9778]

You might be interested in one of the oldest videos on KZbin, called "Blue Marble 3000", which in 500 year steps starting in the year 19,000 BCE shows a world map depicting ice sheets and inland lakes, as well as a map legend showing sea level and CO2 ppm and world average surface temperature. Ideally, the channel owner or one of her moderators will leave a link to that video in this discussion chain. The first half minute or so of that video gives academic credit to scholarly entities such as the University of Bremen in Germany, after which the series of world maps appears, with each map depicting a time 500 years after the previous map, and staying on screen for a few seconds before going on to the next map in the series. The years 19,000 BCE through 2000 CE are shown, covering a time span of some 21,000 years. It is truly amazing how fast CO2 rose between the year 1500 CE, a time when Christopher Columbus was still engaged in a series of expeditions to explore the Americas, and the year 2000 CE, which occurred about a hundred years after the inventions of the automobile assembly line and the airplane.

[@klauskarpfen9039]

@@GEOGIRL Just to "bury" you in suggestions, there is a channel "OZGeographics" and another "Bright Insight" by Jim Corsetti, who covers stuff like more recent impact events such as the "Burckle crater" (east of Madagaskar, in the Indian Ocean) and what role these might have played in historic events. This is also the research object of the "Holocene Impact Working Group" - fascinating stuff.

[@DrSmooth2000]

​@@wendydelisse9778glacial maximum earth is pretty depressing but not seen it animated

[@johnvl6358]

😎

[@terenceiutzi4003]

Of course it was. How much has the earth has cooled!

[@kevinroberts781]

Carbon was much more predominant millions of years ago.

[@kevinroberts781]

Key phrase "plants that photosynthesize carbon."

[@sir_byronroy]

From what I know the Earth is slowly getting near to the sun. Anyway, most of us will not be here anymore before the planet burns. Most likely the New Earth will be Mars.

[@salinagrrrl69]

I bring up to people with an attention span of at least 30secs that take away or add one extinction event & ....no E=MC2 no JWTS no GOD particle NO US.

[@terenceiutzi4003]

No, the steady cooling of the earth has made the climate more stable with slower cooling and shorter warming periods.

[@DrSmooth2000]

Steady since when?

[@terenceiutzi4003]

@@DrSmooth2000 the last 200 000,000 years!

[@DrSmooth2000]

@@terenceiutzi4003 lot of undulations since Triassic Jurassic Boundary Event but yes suppose overall down

[@terenceiutzi4003]

@DrSmooth2000 yes but as very stable drop when compared to previous shifts. A couple of years ago, they found a 20,000 years old fossil of a 150 ft. Anaconda in the amizon and any biologist will tell you that the temperature would have to be 10 degrees C than now for a cold blooded reptile to grow that big!

[@terenceiutzi4003]

@@DrSmooth2000 and global temperature rose 6 degrees from the dark ages to the medieval warm period then dropped 7 during the Maunder Minimum and now has risen .5 degrees if you forget about our present in ability to measure temperature,

[@motophish]

DUH! WITHOUT ICE CORE SAMPLES, YOU WOULDN'T KNOW ANYTHING. NOTHING NEW....

[@GEOGIRL]

Sorry, I'm not sure I follow. Ice cores only apply to geologically recent history, whereas this video is about much more ancient periods in Earth's history, so all of what I discuss here is known from rocks, not ice cores. Sorry if that wasn't clear! ;)

[@CUBETechie]

A little bit of speaking pauses would be great

[@GEOGIRL]

Thanks for the feedback! I’ll work on it :)

[@mikesully7212]

comment

[@knowledgeckr786]

Why do you always make individual videos. You don't have any social life. Lol. Also share your views about role of time management and social life in students ' performance.

[@Charlie-Em]

👉📏📐📏👩‍🦱💄💋 geo girl