Did Snowball Earth Cause an Explosion or Extinction of Life? GEO GIRL

The 'Big 5' Mass Extinctions of the Phanerozoic Eon (within the last 540 million years) get the most attention due to the more complete fossil record of this time. However, there were mass extinction events long before 540 million years ago; they are just harder to quantify due to the lack of preservation of the microbial life that lived during that time. In this video, I talk about a mass extinction event that occurred over 700 million years ago and was potentially larger than all the of Big 5 mass extinction events since! This mass extinction event was caused by the Cryogenian Snowball Earth event, during which Earth's oceans were nearly completely covered in ice, leading to extremely limited photosynthesis, a rapid global increase in seawater salinity and viscosity, major ocean stagnation due to lack of circulation and mixing under the ice, and thus, major biological devastation and extinctions. Hope you enjoy! ;)
0:00 Rise of Oxygen on Earth
3:04 Snowball Earth
5:15 Snowball Earth & Explosions of Life
6:49 Snowball Earth & Extinctions of Life
8:00 Argument for “Slush Ball” over “Snowball”
11:06 Where & How Life Survived
11:29 Other Extinction Causes
14:40 2nd Mass Extinction?
15:33 Explosions of Life after Snowball Earth
16:33 Was this the Largest Extinction of All Time?
References:
Halling et al., 2024: Snowball Earth viscosity drives multicellular evolution- doi.org/10.1101/2024.02.06.57...
Hoffman et al., 2017: Snowball Earth climate dynamics and Cryogenian geology-geobiology- doi.org/10.1126/sciadv.1600983
Griffiths et al., 2022: Animal survival strategies in Neoproterozoic ice worlds- doi.org/10.1111/gcb.16393
Casado, 2021: Review of the Neoproterozoic Global Glaciations and a Biotic Cause of Them- doi.org/10.1007/s41748-021-00...
Gan et al., 2022: Earliest Ediacaran speleothems and their implications for terrestrial life after the Marinoan snowball Earth- doi.org/10.1016/j.precamres.2...
Earth System History: amzn.to/3v1Iy0G
Geomicrobiology: amzn.to/2WAloTR
Ediacaran Extinction & Cambrian Explosion- doi.org/10.1016/j.tree.2018.0...
Anoxia during Ediacaran- doi.org/10.1126/sciadv.aan8983
Ediacaran Mass Extinction- doi.org/10.1098/rspb.2015.1003
Hydrogen sulfide increase in ocean during Ediacaran-Cambrian transition- doi.org/10.1038%2Fnature07072
GEO GIRL Website: www.geogirlscience.com/ (visit my website to see all my courses, shop merch, learn more about me, & donate to support the channel if you'd like!)
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Oxygen by D. Canfield: amzn.to/3gffbCL
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[@GEOGIRL]

So I see a lot of people in the comments saying, "of course it was both, every extinction event is followed by explosions of life due to newly opened niches". While this is true, I would like to just again emphasize the difference between this event and others. The more recent extinction events that we have a fossil record for (like the Ordovician, Devonian, Permian, Triassic, and KPg) all caused major devastation followed by major biodiversification. But remember these events all occurred after animals and plants had evolved and become globally widespread; so essentially, many animal and plant species went extinct and new animal and plant species diversified in those open niches after the extinction event. Thus, these events didn't create enitrely new groups of organisms that completely altered the biosphere. Whereas, the extinction and explosion events associated with Snowball Earth (discussed in this video) did just that! Before this event Earth was dominated by single celled organisms, many of which did not metabolize (or event tolerate) oxygen (O2), but after this event, animals and other O2 metabolizing organisms became dominant. The biosphere was never the same! Think of it this way to visualize the difference in events: The KPg led to a change from dinosaurs (animals) dominating to mammals (still animals) dominating; whereas, Snowball Earth caused a global shift from single-celled organisms to huge, weird, Ediacaran animals! It's a massive difference! I just think that is SO COOL and makes this event one of my favorites!! :D

[@charlessarver1637]

❤️❤️❤️

[@davidcote5637]

The Snowball Earth event is "SO COOL"! LOL! ...and SO COLD!

[@paulhague5590]

Rachel, I'm a retired geologist (near-surface geophysics) who just stumbled across your videos on KZbin. Brava! I'm very impressed. I feel old and stupid - -but I got my BS in 1973 at UMASS Amherst.

[@justfellover]

Some people neglected to watch Star Trek II: The Wrath of Khan and it shows. Destruction and creation are the same event.

[@domonkosscheiling5809]

"multicellularity was this new and fun thing" "let's diversify!" this made my day. thx!

[@georgefspicka5483]

It was as if they got together and voted on it 😂

[@domonkosscheiling5809]

@@georgefspicka5483 they did. and the opposition died out

[@robertab929]

Multicellularity appeared several hundred million years BEFORE Snowball Earth (before Cryogenian).

[@PaleoEdits]

I think it's worth noting that even IF snowball earth was glaciated from pole to pole at any one point, photosynhetic life could still have found refuge within cryoconites.

[@justfellover]

I was wondering, with an entire surface of ice, how is geothermal heat radiated? I would expect large voids in the ice wherever both crust temperature and elevation are high enough. These would stop melting before reaching the top of the ice, but after making it thin enough to become partly transparent. This transparency would allow heat to radiate into space, and power heliotropes. All the ingredients in this might be long lasting, in ecosystem time.

[@howardrisby9621]

​@@justfelloverInteresting thought. I'd be very interested to hear what the relevant scientists have to say on that. You probably noticed, I don't even know what branch said relevant scientists come!!

[@apersonlikeanyother6895]

One thing I love about this channel. I know a little about the subject and she adds the correct details backed by science. So much better than science communicators who oversimplify things until it's actually incorrect.

[@Dajobi1]

I can't believe your channel hasn't appeared in my feed before! I love the technicality of the content. So refreshing when there is so much average content these days.

[@APRENDERDESENHANDO]

Amazing as always! The snowball Earth and the breakup of Rodinia are also hypothesized to be the causes of the Great Unconformity in the geologic record

[@ausgruenden1590]

I'm fascinated by everything Precambrian, and Geology is the closest thing we have to a time machine. Thanks for these travels to *very* deep time!

[@whatabouttheearth]

If you want content to learn about the (very important) Proterozoic this is your gal. Before I knew better I just thought, "oh, pre Cambrian, there's nothing interesting back there", boy was I wrong. Once I started learning about photosynthesis and its origins deeper, and getting into things like hydrothermal vents and the effects of not just oxygen, but also chemosynthesis on the biosphere, it started to pan out and the Proterozoic became an extremely fascinating and fruitful eon yo study more. Knowledge of the Proterozoic will set you up well for understanding better the why and how of the origin of animals and plants, and all the other contexts if the Paleozoic eon. And she's right on Canfields book 'Oxygen: A Four Billion year History', check it out. I'm learning that in the biosphere, and even in abiotic existence, many times the smaller is bigger.

[@PaleoEdits]

You should check out Nick Lane's books as well, if you haven't already

[@whatabouttheearth]

​@@PaleoEdits Oh, I have, I got them on LibGen PDF but I want to learn ALOT more about the Krebs cycle and respiration before I buy physical copies and try to tackle those. 😂 It's on the list.

[@whatabouttheearth]

​@@PaleoEdits Oh, I have, I got them on LibGen PDF but I want to learn ALOT more about the Krebs cycle and respiration before I buy physical copies and try to tackle those. 😂 It's on the list.

[@TheInterloafer]

The end-Permian may not have actually been the worst mass-extinction event, just the worst-recorded = my mind, blown! Thanks for an extremely fascinating video!

[@GEOGIRL]

I know right! Thanks so much, so glad you enjoyed it ;D

[@williammoore3279]

Fascinating content - thank you. I'm an old man now so I might be remembering this wrong. While stromatolites/cyanobacteria photosynthesis accounts for oxygen, I thought the major contributor to Earth's oxygen level happened when snowball Earth experienced an increase in volcanic activity. Volcanoes released significant amounts of CO2 (negating the reflective quality of the ice and trapping heat) triggering the ice to melt. Over the millions of years of snowball Earth, solar radiation had interacted with the water molecules to create a form of hydrogen peroxide. When the ice melted, the transition released massive amounts of oxygen and the process also helped form the ozone layer.

[@GEOGIRL]

Yes! The second oxygenation event and associated snowball Earth event (the one discussed here) was caused in part by spread of new photosynthesizers, like algae (as cyanobacteria had caused the one billions of years prior), but also by volcanism that likely released ash and sulfur particles into the stratosphere that blocked sunlight, contributing to the cooling and ice formation. However, I haven't heard about any significant molecular oxygen (O2) formation from abiotic processes like you mention, that is so interesting! I will have to look into that ;D Thanks for sharing :)

[@williammoore3279]

@@GEOGIRL Never expected a reply, and want to thank you for taking time. I decided to spend the day researching this (I'm retired so have plenty of time) as well. It was something I may be remembering incorrectly. Thank you again and thank you for your wonderful content.

[@punditgi]

Geo Girl always causes an explosion of knowledge! ❤🎉😊

[@joecanales9631]

Howdy Rachel, thanks for another wonderful presentation of mass extinctions. You noted the rapidity of climate change during the cryogenian but I bet it doesn’t compare to the changes we are currently experiencing. I love your visual graphs and illustrations, I often pause to figure out what is being graphed. Thanks

[@meandyouagainstthealgorith5787]

A happy multicellular Mother's Day to the GEO GIRL.

[@shadeen3604]

Great video thank you Dr Geo girl

[@stevenbaumann8692]

Very well done! I was waiting for you to get to the stromatolites! It's been one of my major points against a completely frozen planet.

[@michaeleisenberg7867]

Rachel 🍍, 🙏 for this fantastic and well put together video 🎬 ! Solid work! 👏👏👏👏

[@GEOGIRL]

Thanks so much! So glad you liked it ;D

[@bernard2735]

Thank you for consistently delivering some of the finest quality science content available.

[@GEOGIRL]

This comment is too kind

[@erickleuro6159]

Thank you very much. I commend you for the quality of your videos, and also from non shying away for complete, comprehensive numericall graphs. Probably covered in the other video, but snow ball earth theory was controversial as recently as 20ish years ago

[@georgefspicka5483]

Hi there Geo Girl ~ And yet another great mind expanding presentation. I already knew some of what you were talking about, but it's like you were continually peeling layers back and exposing (at least to me) information that I wasn't aware of yet. One thought I had with all this climate change going on, was what role did the Milankovitch Cycles play in this? I'm assuming that they were operating back then, just like today. I often read about them being the source of changing climate during the Pleistocene Epoch, yet further into the past, there seems to be no mention of them. I'm assuming that there was no major changes in Earth's orbit, so where did they go?

[@altanativeftw2625]

There were still Milankovitch cycles. They just don't operate on grand timescales of tens of millions of years. As a side note, the cause of the present ice age (because we are still in one) had nothing to do with Milankovitch cyles but with a CO2 drop during the Eocene-Oligocene boundary. Milankovitch modulate climate on short-term timescales but are not a long-term driver of climatic changes.

[@georgefspicka5483]

@@altanativeftw2625 Then what timescale do the Milankovitch cycles operate on? According to NOAA, interglacial episodes coincide with solar peaks, and recycle about every 23,000 years - www.ncei.noaa.gov/sites/default/files/2021-11/1%20Glacial-Interglacial%20Cycles-Final-OCT%202021.pdf Our current Ice Age began about 2.6 million years ago, but there seems to be nothing mentioned about Milankovitch cycles before that. Assuming that there was no interruption of the cooling that began some 34 million years ago, I would think that the cycles would be present, especially since they’re driven by permutations of Earth’s orbit. Perhaps the problem is that our technology isn’t developed enough yet to detect the cycles, unless they’re effecting the planet in a major way. The drop in CO2, do you think that also may have been responsible for the Eocene-Oligocene Extinction Event? Some think it may have been due to the Chesapeake Bay Bolide, and associated Popigai impact structures. You mentioned a timescale of tens of millions of years. Which one is that?

[@hdufort]

Will you make a detailed video about ocean stratification? Today, the Black Sea is stratified and has anoxic layers. But back in the Proterozoic, and for a long time, the global oceans were layers. At times, the ocean layer that could actually sustain life was very shallow.

[@charlessarver1637]

Fascinating. I love the detail as always👍👍👍

[@hdufort]

Don't forget Gaskiers. Very short (340 kyears), but intense glaciation. A pulse really. Ediacaran biota started showing up immediately after Gaskiers. Why is that so? Maybe the quickly receding glaciers left behind ample amounts of organic matter and dissolved oxygen, along with very dynamic thermohaline circulation.

[@WillPhil290]

This is kind of irrelevant to this specific video... But it is relevant to your influence and how much your channel means to people. You are really wonderful and do a great job in teaching people like me... My cousin is taking HVAC courses and he's struggling a bit. He's like, "they're asking me things like, how do I reduce the freezing point of water?"... I go... Add salt?... And he's like... Yeah, how did you know that??? I'm like ummm geo girl taught me about icebergs like a week ago? It seemed logical... Lol... Love your work ❤️

[@FH80667]

I hope you're well! I love your videos and have learned so much from them. I was wondering if you could consider making a video about contour currents (also known as contourite currents). These are deep-sea currents that flow along the contours of the ocean floor and play a significant role in sediment transport and ocean circulation. I think it would be a fascinating topic for your audience!

[@GEOGIRL]

Thanks for the suggestion! That sounds like a great idea! I am putting it on the list ;D

[@muzikhed]

Hi, thanks. So much info in such a short video.

[@iamsuzerain3987]

Great work on this video, truly enjoyed watching❤👍

[@ahmadrajjouh8473]

Thank you so much , really your explanation always making my day.

[@GG-dx6cu]

Great like always 😊

[@GEOGIRL]

Thank you! :D

[@karlthemel2678]

Volcanic areas like hot spots could turn ocean surface ice >slushy

[@Arycke]

Nice video! Thanks for the upload. One small thing, unrelated to this video, is that there is a typo on your channel description. It says "Whether you studying" Meant to be "Whether [you're] studying" Thank you for your attention in this matter.

[@GEOGIRL]

Oh, thanks haha I can't believe I didn't notice! You are the best!

[@Arycke]

@@GEOGIRL sure thing, no problem! Thank you for responding, I appreciate it. Feel free to delete my comment, I just didn't have another way to reach out to you quickly. Thanks

[@Chiavaccio]

Cool video!👏👏

[@takashitamagawa5881]

I suppose it's difficult to quantify and compare the magnitudes of these mass extinction events which are so far separated in time and life form complexity. And such would still be the case if the fossil record were more complete. Comparing the loss of microbial life diversity and numbers to the loss of multicellular fife forms at the end of the Permian involves subjective judgement, I would think. It is easier to compare say the end of Permian extinction to the Devonian and the end of Cretaceous extinctions. The most salient point is the intertwined nature of extinction and diversification events in the history of life. Excellent presentation!

[@neleig]

Informative and enjoyable. Thank you.

[@CCrohny]

I think an interesting video idea will be the on the legitimacy of the snowball Earth theory. There is plenty of evidence to suggest the Earth didn't completely get covered in ice and yet there is other evidence suggest it was. Its also funny because the owner of the Snowball Earth theory and the owner of Slushball Earth theory had a massive fight at a conference.

[@palantir135]

Ice lets more light through than you think. In the upper meters of ice, algae and photosynthetic bacteria can live and multiply. This is still the case on Antarctica.

[@PaleoEdits]

Nope, "archeabacteria" is an obsolete term for archaea, non of which can photosynthesises and so produce oxygen as a byproduct. Cyano-bacteria with water based photosynthesis can.

[@palantir135]

@@PaleoEdits yes, you’re right. My memory lets me down. I learned Archeabacteria as the name for these organisms many decades ago, and that name keeps popping up automatically.

[@whiskeytango9769]

It seems to me that most of these mass extinctions do both...great presentation once again. I have no idea how you find the time to both research and build the presentation.

[@GEOGIRL]

That's so true! Mass extinctions are devastating in the moment, but tend to lead to even greater biodiversification after the fact due to newly opened niches and adaptations. :) Thanks for the kind words! Making these videos is my hobby so I think of it as my time off ;)

[@barbaradurfee645]

Love this zoom in on the GOE-NOE, nice work! I need you to explain the carbon isotope chart vs time at about 6.5min in. I did not make the connection with the dots & colors. ❤️❤️

[@GEOGIRL]

Oh that chart was really just to show that the Ediacaran directly follows the Cryogenian which is to show how Snowball Earth may have directly led to biodiversification in the Ediacaran. I talk a lot more about the Carbon isotope excursions during snowball earth in my snowball earths video: kzbin.info/www/bejne/g6u8qmyYer-hmNk ;)

[@barbaradurfee645]

Thx, I was going to look at your references 😊

[@barbaradurfee645]

@@GEOGIRL OMG pigtail Rachel !!! What a delightful Mother’s Day ❤️

[@barbaradurfee645]

Well I’ve gone down a delightful rabbit hole about Boron, so thanks for that. Is there a map that shows in simple colors the pre GOE rocks, the GOE-NOE rock exposures on Earth?

[@barbaradurfee645]

Wow your sound quality is so much better than pigtail Rachel’s.

[@mandobob]

Howdy Geo Girl! One thing I have thought for many years is that the extensive "land" erosion during the Neo-protozoic (either just run-of-the -mill erosion or glacial, or both) would result in high chemical compounds (nutrients?) loads to the seas. That may have been a large factor in rapid evolution observed Ediacaran and especially in the Cambrian.

[@GEOGIRL]

Absolutely! I talk about that a lot in my original NOE video! That was likely a massive factor in both causing the NOE and potentially the explosions of life! :)

[@nw5524]

Great content! Is there a video on the feeding habits of the Ediacaran fossil Kimberella?

[@GEOGIRL]

Thanks! Not yet, but maybe in the future :) I plan to make more on the Ediacaran biota as I find them so facinating! ;D

[@terenzo50]

Adaptability is the key to survival.

[@meesalikeu]

could you do a video for us on early earth geology? i mean earth mark one aka before the moon event as its sometimes called? like what geologic changes did the moon making impactor bring to the pre-earth earth? and also i sometimes read there may have been life. thx 🎉

[@barbaradurfee645]

Ok, because you forced me to rewatch snowball earth video and the read up on Boron, I’ve learned the B is critical to RNA process so I’m wondering if the broad evaporite deposits formed in epeiric seas after the end on the Cryogenian glaciation may have help B concentrations rise and help trigger complex multicellular life in those warm, sunny seas?

[@GEOGIRL]

Well you are ahead of my knowledge on this topic now haha, so I don't know but that sounds logical to me ;)

[@barbaradurfee645]

Add Boron to your isotope video list 😊

[@barbaradurfee645]

Also, the boron articles on Mars from NASA are super interesting and you would enjoy them.

[@johnthomasriley2741]

Micro organisms now live well on the underside of ice shelves. Stable temperatures, mild summer sunlight.

[@philochristos]

If earth completely froze over for 70 million years, would an alien civilizations a hundred or more light years away have looked at earth and still said it was in the habitable zone?

[@GEOGIRL]

That is such an interesting and important question! I love this comment because people always think of Earth as being the blue planet with all this life, but it wasn't always that way, billions of years ago it was Mars that had a bunch of running water on its surface (and potentially even life) while Earth was going through these major events like snowball earth, so it really depends on *when* you look at our solar system. Billions of years ago there was no macro-life, and no green, plant-filled land, so aliens probably (from a far) would have assumed no life, but today that is far from true, so yes, it heavily depends on timing! That said, determining whether a planet or moon is habitable is different than determining whether it is inhabited. For example, we think that the oceans beneath the thickk icy crust of Europa and Enceladus (moons of Jupiter and Saturn) are habitable, but we just don't know whether they actually host life. So, aliens (if they defined habitability the same way as us) would've probably said, ok Earth is likely habitable but we would have to actually go down to the surface and examine the ocean underneath the ice to say whether it actually has life. Hope that makes sense ;)

[@Embassy_of_Jupiter]

Sort of Off-Topic: I recently did some math on the Great Oxidation Event and I don't think it makes sense to call that an extinction event. It took 400m years, for bacteria that's enough time to change every base pair in their entire genome TWICE. It's more likely they all just adapted to the oxygen conditions, rather than die out.

[@whatabouttheearth]

One for the algorithms

[@user-rw3xn8xu8b]

what about the theory that life persisted in pools of melted ice on the surface?

[@josemariatrueba4568]

As far as I know melting ice above emerging continents is not the main cause of sea level rise. The average temperature of the oceans is mainly ŵhat causes sea level rise because water has a dilatation coeficiente that makes sea levels go down during ice ages and going up during warmer periods. This is why the British islands are connected to the European continent during ice ages when sea levels are more than 120m lower than right now.

[@supersleepygrumpybear]

I think the Moon is a bigger factor than we (the collective zeitgeist of civilization) realize, but I'm a bit of a lunatic 🤣😂 I'm pretty sure alien moon rocks are out of the question; it's more- what the Moon's tidal forces were like during Snowball earth; how the Moon's rotation and distance were different; how Earth's rotation (the days) were different; what impact events might be visible on the moon, and yet, invisible on earth (signs of previous impact events, classic extinction story lol); but most importantly- I like to imagine the snowball earth with the fiery moon, phantom volcanoes erupting within the Imbrium Basin- (I know the timescales don't match, it sounds super cool;)

[@sassa82]

Wow!

[@ecocentrichomestead6783]

Biodiversity depends on variability. Natural climate changes are one type of variability. Also, Phototrophs must have evolved before the animals that eat them. Without predators, the phototrophs would multiply unchecked until they used up the available CO2. Snowball earth decreased the Phototroph population until the Animal life could catch up. greenhouse gas levels are maintained by a balance between plant and animal emissions.

[@bigkirbyhj666]

It was both, you can't have an explosion without niches opening up from an extinction.

[@bigkirbyhj666]

One of my favorite paleo youtubers frequently brings that point up when talking about the planets progression.

[@FRPlayerOne]

"Immediately after" or about 70 millions years 😅 Like we appeared immediately after the dinosaurs lol

[@GEOGIRL]

Well, in geologic time haha ;)

[@nickcharles1284]

I would watch this, but it had 'forgotten' in the title. So I didn't.

[@johnp9988]

🍻

[@GeoffryGifari]

Do we know how long ice ages/snowball earths can last? (and the factors affecting that)

[@craigkdillon]

Every mass extinction leads to a burst of new species. For instance, the extinction of the dinosaurs allowed the mammals to flourish. The Permian extinction allowed the Dinosaurs, Pterosaurs, and Icthysaurs to flourish. Extinction wipes the slate clean creating space for new species.

[@beachboardfan9544]

🤔 Interesting I always thought thermal convection currents caused water mixing and wind just caused surface waves.

[@danielauto3767]

No, because for thermal convection to work the water needs t be heated from below, like in a pot of water. The ocean's circulation is driven by wind and salinity. Salty water is dense and tends to sink.

[@GEOGIRL]

You are right that surface water currents are driven by wind and deep water circulation is driven by the thermohaline converyer belt (which is driven by temperature and salinity of the water rather than wind); however, vertical mixing through upwelling and downwelling is different than large scale circulation or currents, it is more just the vertical motion and mixing of the deep and shallow waters at continental margins, but this in turn helps to drive the ocean conveyer belt. And it is this vertical motion, the upwelling and downwelling, that can be driven by wind. It can also be driven by temperature and salinity at the poles, but at non-polar margins it is typically driven by wind ;) Hope that makes sense!

[@the_eternal_student]

I recently thought it might be beneficial to have the body seperate into one-celled bacteria, of course, then i realized that is just death.

[@MediaFaust]

If earth is already covered with snow, where does "more snow" come from?

[@brucewinningham4959]

Could more snow on top of already existing snow lead to Icebergs & Glaciers? TiA.

[@HerrFinsternis]

10:55 Or ..... a pokeball, containing the next evolution.

[@a.randomjack6661]

Bonjour Docteure GEOGIRL I came across this last week "Did a magnetic field collapse trigger the emergence of animals?" Evidence suggests a weak magnetic field millions of years ago may have fueled the proliferation of life. Researchers uncovered compelling evidence that Earth's magnetic field was in a highly unusual state when the macroscopic animals of the Ediacaran Period -- 635 to 541 million years ago -- diversified and thrived. Thought it would interest you. I'll let you search for it, can't post links anymore Thanks again 👍

[@stevedrane2364]

Brilliant. . .If only more of us Homo Sapiens could know how lucky we are to have survived. . So far . .

[@GeoffryGifari]

Is it possible to take advantage of photosynthetic microbe proliferation to control the climate?

[@brucewinningham4959]

GeoGirl, if our Earth didn't have oxygen until the Great Oxygenation Event, how did Earth get so many molecules containing Oxygen Please, that make up the Rocks Please, such as but NOT limited to, such as Calcium Carbonate, Silicon Dioxide, etc.?

[@GEOGIRL]

I am sorry I always forget to clarify that when I say Earth lacked "oxygen" I am refering to molecular oxygen (O2) which is the oxygen molecule in the air and in the oceans that animals, like ourselves, breathe to metabolize. Oxygen as an element was always around as Earth is made up of primarily silicate minerals (which contain SiO2), and it was also around in water (H2O) as well as a bunch of other gases and minerals like you mention. So, I mean the molecule, oxygen, not the element, oxygen. I am sorry for the confusion!

[@joeanderson8839]

If Bacteria can go dormant for 70 million years and then come back to life, we would have no way of knowing it. How could we test such an event?

[@hdufort]

Could life thrive in salty lakes on top of glaciers, and on soot deposited on glaciers by volcanism? Also, would a snowball Earth have lakes around active volcanoes and hot spots? There would certainly be surface refuges, especially due to regional volcanism.

[@jamesdriscoll_tmp1515]

I wonder if warm water from rifts and hot spots created a diferent style of ocean circulation?

[@mlgoreable]

Missed a Doctor Malcolm opportunity there at 10:51

[@nicholasmaude6906]

Snowball Earth could've been called Hoth, Rachel, well Earth has been like that several times.

[@GeoffryGifari]

Hmm can photosynthetic microbes live ON the ice and continue absorbing light?

[@grigorione7824]

what if Ice ages are some kind of cocoon and a metamorphosis takes place . not all over , just in some places. And when the ice melts.. they know what they are and what they eat etc.. like how a moth knows how to fly without lessons .

[@j.christopherbowen252]

❄️🌍🌞👍

[@drewtheceo9024]

Snowball earth sounds good right about now. Jk. My solar storm jokes are bad. 😅

[@Troy-ol5fk]

desalination can be achieved by simply freezing sea water?😮

[@josemariatrueba4568]

Isn't it better to replace the words "our hiatory" with "our prehistory". Properly speaking our history is only 50 to 100 centuries old. Anytime before that is pre history. Times when we must guess about because we don't have access to written information about.

[@legendre007]

I was very excited to learn from your videos of the idea that this snowball Earth contributed to colonies of single-celled organisms eventually becoming multicellular organisms with different kinds of specialized cells. ☺🦠

[@Yestradamus-]

Yes.Yes it did cause those events.

[@delamr1]

will this happen again?

[@judychurley6623]

PRODUCED O2, or FREED O2 from other compounds?

[@gregoryrollins59]

I have an issue. Snowball Earth was 710 to 640 million years ago. Yellowstone last erupted 640 million years ago, and the US was part of pangea until about 300 million years ago. So something is going on. Something doesn't seem right. Could you make that make sense? Because it doesn't. Peace and Ahev

[@davidhoward4715]

Eh?

[@GEOGIRL]

Yellowstone actually didn't form until about 640 thousand years ago (not million) and it last erupted much more recently (I believe about 70 kyrs ago), so this snowball earth event occurred hundreds of millions of years before Yellowstone even formed. However, that said, snowball Earth didn't necessarily negate volcanic activity. Volcanic eruptions were still going on, especially underwater volcanos in the ocean or hydrothermal vents (as they do during any ice age, it is just that the cooling and ice formation processes dominate over any warming that may be caused by the volcanism). So, in other words, volcanism does not negate snowball earth in any way. In fact it is thought that volcanic activity just before the Cryogenian may have helped cause snowball earth by putting so much ash into the stratosphere which blocked incoming sunlight, and cooled earth. As for the second part of your question, Pangea was actually just beginning to form around 300 to 250 million years ago, it wasn't until later in the Triassic, around 200 million years ago that Pangea really started to break up; however, I am not sure what Pangea has to do with snowball earth as these events happened hundreds of millions of years apart from one another. I hope that helps clear up at least the timeline of events. I am happy to answer any other questions ;)

[@gregoryrollins59]

​@GEOGIRL, thanks for getting back. After your video, I did some more reading. I started thinking about what was under the ice, so I did some reading about pangea, which made me think of Yellowstone. Don't know why. I just did. All I saw was 640. I had millions on my mind. Lol, I just didn't look close enough. Even funnier, I asked USGS the same question. They pointed out the same as you. Thank you for letting me know I was mistaken.

[@justfellover]

Is a 'PhD crease' a new facial feature that emerges with advanced education?

[@ogrejd]

Cyanobacteria: Trying to murder all other life on Earth for 2.5 billion years and counting. :P

[@Neobert5240]

Is it true cow farts will send us into an ice age??? Lol you know it's kinda mean to blame the cow 🐮 when people out number cattle??? Plus Taco 🌮 🛎Bell!!! Lol Aloha's 🤙👍⭐️⭐️⭐️⭐️⭐️🦮💨🙊🙈🙉💯🤪

[@JamesWhite-yj7sd]

snow ball earth is a theory not a fact

[@GEOGIRL]

No, actually it's a hypothesis. Theories in science are very well-founded, like gravity. The Snowball Earth hypothesis is very well backed up, but since we cannot go back in time and actually see it, it will remain a very well evidenced hypothesis :) However, that is not to discount any of the things I say in the video, it is still the most likely scenario based on our current data, which I think is super cool! :D

[@jonwashburn7999]

sometimes to create, you must first destroy

[@raulvidal2343]

Neoproterozoic animals, lystrosaurs, dinosaurs and mammals after surviving mass extinctions and then diversify and conquer the world: "Whatever doesn't kill you, simply makes you... stranger 🤡"

[@carolgebert7833]

Btw -CO2 does not control climate. At the time of snowball earth the CO2 level was about 8,000ppm. If CO2 truly controlled temperature, then the snowball earth event would never had occurred.

[@michaelwood368]

please marry me

[@secularsunshine9036]

*Join the Enlightenment* *Support Secular Humanism.* *Don't be left behind.* I didn't hear you address volcanic activity, continental drift and the massive world wide ocean rifts and ridge system as it seems that you conveniently ignored it. thanks anyway.

[@davidhoward4715]

Stick to your Jesus magic.

[@cavetroll666]

Salute from Toronto 🦝 thanks for the content listening while I work my factory job lmao geting educated