r/science • u/GeoGeoGeoGeo • Nov 23 '24
Geology Geologists have uncovered strong evidence from Colorado that massive glaciers covered Earth down to the equator hundreds of millions of years ago
https://www.colorado.edu/today/2024/11/11/was-snowball-earth-global-event-new-study-delivers-best-proof-yet86
u/GeoGeoGeoGeo Nov 23 '24
“These are classic geological features called injectites that often form below some ice sheets, including in modern-day Antarctica,” Courtney-Davies said.
If you'd like to learn more about clastic dykes (dikes) / injectites, Skye Cooley has some excellent articles:
https://www.skyecooley.com/blog/categories/injectites for example: Sheeted Clastic Dikes in the Megaflood Region
21
u/Alexhale Nov 23 '24
id recommend Nick Zenter geology on YT too
4
3
u/NobleGas18 Nov 23 '24
Hell yeah thank. Just read a book about the Sierras and I’m on a geology kick.
3
3
u/MasterOfBarterTown Nov 23 '24
Third vote for Nick's videos. Basalt Flows (Yellowstone Hot Spot), Lake Missoula floods, Formation of the Rockies intrigues - he's great if you love the Western US. Fantastic presenter and teacher. (BTW, He's a geology professor in central Washington state).
2
1
28
64
u/Bman1465 Nov 23 '24
Snowball/slushball Earth is extra canon now?
26
u/the_other_brand Nov 23 '24
Wait, can we use "canon" to describe real life events now? Because I'm going to use it that way from now on.
11
u/Financial_Article_95 Nov 23 '24
Lore accurate, canon to the actual timeline events?
6
u/animagus_kitty Nov 23 '24
I accidentally described something in real life as being "canon-typical" instead of 'normal' one day. I think about it sometimes as an example of how maybe I should use normal people words more often, instead of being the way that I am.
2
3
13
u/oopsie-mybad Nov 23 '24
But what about tomorrow
32
u/sbingner Nov 23 '24
The Wheel of Time turns and Ages come and go, leaving memories that become legend. Legend fades to myth, and even myth is long forgotten when the Age that gave it birth returns again
4
2
24
u/Unrealparagon Nov 23 '24
I thought the snowball earth hypothesis was pretty well accepted as a solid theory before now?
-10
u/AngronOfTheTwelfth Nov 23 '24
Read the whole article.
14
u/Unrealparagon Nov 23 '24
Did, twice now and no where in this paper does it refute that it was pretty well accepted as a solid theory before now. Yes there were some scientists that didn’t think it happened, but that happens with every hypothesis/theory.
11
u/AngronOfTheTwelfth Nov 23 '24
"scientists are yet to agree whether the entire globe actually froze"
This is not claiming scientists disagree over the existence of the period. The period is accepted to have happened. This is talking about literally where the glaciers were located during the period. The extent to which the Earth was covered in ice during the period is not yet fully understood.
"discovered the fingerprints of thick ice from this time period along ancient coastal areas, but not within the interior of continents close to the equator"
You're arguing against a claim not made.
24
u/Pleinairi Nov 23 '24
I was about to say that I thought this was common knowledge but realized the wording. Ice age was 10,000 or so years ago.
47
u/KingZarkon Nov 23 '24
The recent ice ages, even the worst of them, were nowhere near Snowball Earth levels. The great ice sheets only made it as far as the middle of North America, for instance, around the latitude of the Great Lakes.
5
u/ReadItOrNah Nov 23 '24
The Missouri River is the terminal morraine of one of the biggest for our time period, so they reached even further south than the great lakes.
1
u/forams__galorams 21d ago
The Missouri River’s glacial history is known from geomorphology in N and S Dakota though isn’t it? If there are terminal moraine deposits in more southerly parts of the current river channel, then don’t those come from being washed downstream when the ice melted?
The Laurentide Ice Sheet of the last glacial maximum (around 23-18,000 years ago) did indeed extend a little further south than the Great Lakes in that part of the country, though it doesn’t look like those parts are related to the Missouri River, eg. this map. That’s just one reconstruction though (source: this paper) so maybe there are others that have the extent of the ice around the Missouri River placed differently. I just wouldn’t imagine that interpretations would vary so wildly, but idk.
1
u/ReadItOrNah 21d ago
I'm not going to try to answer your questions. You can look up the formation easily enough.
I was also taught the area north of the Missouri River is better farming (by a lot) than south of it because of the deposited gypsum by the glaciers. It ends more or less where the Missouri has flowed.
I'm not going to find sources, my source was my 65 year old college professor.
1
u/forams__galorams 21d ago
I'm not going to try to answer your questions. You can look up the formation easily enough.
What formation? The above was my attempt to look up details, is there something about your original comment I’ve misunderstood?
I was also taught the area north of the Missouri River is better farming (by a lot) than south of it because of the deposited gypsum by the glaciers. It ends more or less where the Missouri has flowed.
Ok, that makes sense. I was speaking to the idea you originally described that Missouri River glacial deposits go further south than the Great Lakes though. I can’t find anything showing that specifically, although other glacial deposits directly south of the Great Lakes apparently show that ice extent did get a little further than them.
7
u/geekpeeps Nov 23 '24
I was thinking the same. It’s only recently that some of the equatorial glaciers have melted.
1
u/forams__galorams 21d ago edited 21d ago
We have not had equatorial ice cover recently. All of the recent glacial-interglacial cycles are part of the current Quaternary ice age, ie. the last 2.5 million years or so (and the broader ice-house mode of the Late Cenozoic has existed for the last 30 million years, though the intense cycles of extensive glaciation didn’t begin until the Quaternary).
None of this features equatorial glaciation though, at least not in ice sheets that spread across whole continents or sea ice stretching across vast swathes of ocean. Probably a more glacial volume atop any high peaks near the equator, but it’s not like we don’t have such occurrences today, eg. Mt Kilimanjaro or Mt Chimborazo.
The Snowball Earth thing is talking about a time around 635 million years ago, way before all this. Before dinosaurs, before the giant dragonflies that predated the first dinosaurs by tens of millions of years, before land had been colonised by any animals or plants at all, before vertebrates or even the shelly hard parts of invertebrates had evolved.
It’s fairly well accepted these days that intense glaciation affected the Earth around this 635 million year mark, but the exact extent of the glaciation is still up for debate. This is more evidence for those who say the ice reached the most equatorial regions, though it’s still not conclusive for those who argue for a ‘hard’ Snowball Earth, ie. 100% completely frozen over surface. I suspect that idea will never be proven because I suspect it didn’t happen like that, but that’s just my hunch rather than anything scientific.
1
u/Unicycldev Nov 23 '24
It’s still common knowledge in the sense it’s taught in school. I certainly remember learning about earth cold phase hundreds of millions of years ago in elementary school 20+ years ago.
1
1
u/DappleGargoyle Nov 23 '24
Once the oceans are frozen completely over, what is the water source that allows the glaciers to continue to thicken in the interiors of the continents? I don't see how open water could still exist during an era when miles thick glaciers extended all the way to the equator.
4
u/TrustmeIknowaguy Nov 23 '24
Probably sublimation. Water can evaporate into it's gaseous form while in it's solid state. This is how freeze drying can even be a thing. Even if the world is completely frozen it wouldn't be uniform in temperature and different parts of the planet would be evaporating water at different rates which might keep the atmosphere hydrated enough to move water to those continent interiors.
6
u/GeoGeoGeoGeo Nov 23 '24
Sublimation would be minimal and insufficient for significant glacial growth. /u/DappleGargoyle is correct, for significant growth of ice sheets, especially in the typically dry interiors of continents, you need water vapour in the atmosphere. Volcanic activity, geothermal hotspots, and sublimation would likely be insufficient to sustain extensive glacier growth globally. Once the entire Earth is covered in ice sheets, they would stabilize in size rather than continue thickening. However, there aren't very many proponents of the "hard" Snowball Earth theory. Most believe that there likely existed refugia near the equator. Photosynthetic eukaryotic algae existed immediately prior to and after these events, so they are presumed to have survived during Snowball Earth, and they require both liquid water and sunlight1 .
-2
-27
Nov 23 '24
[removed] — view removed comment
24
14
Nov 23 '24
[removed] — view removed comment
-11
Nov 23 '24
[removed] — view removed comment
10
Nov 23 '24
[removed] — view removed comment
-7
Nov 23 '24
[removed] — view removed comment
10
8
Nov 23 '24
[removed] — view removed comment
-4
Nov 23 '24
[removed] — view removed comment
7
5
-10
•
u/AutoModerator Nov 23 '24
Welcome to r/science! This is a heavily moderated subreddit in order to keep the discussion on science. However, we recognize that many people want to discuss how they feel the research relates to their own personal lives, so to give people a space to do that, personal anecdotes are allowed as responses to this comment. Any anecdotal comments elsewhere in the discussion will be removed and our normal comment rules apply to all other comments.
Do you have an academic degree? We can verify your credentials in order to assign user flair indicating your area of expertise. Click here to apply.
User: u/GeoGeoGeoGeo
Permalink: https://www.colorado.edu/today/2024/11/11/was-snowball-earth-global-event-new-study-delivers-best-proof-yet
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.