Multiple snowball earth events have occurred through earth history. This video covers the Makganyene (2.1 billion years ago), Sturtian (716 million years ago), and Marinoan (635 mya) glaciations. Specifically, the timing, the causes (weathering as a carbon sink, volcanic activity- emission of sulfur compounds into the stratosphere, the sun's intensity- the sun was dimmer than today, and the albedo positive feedback associated with ice cover), the evidence (global distribution of glacial deposits, banded iron formations- BIFs, cap carbonates, carbon isotopes, boron isotopes, iridium layer, subsidence and deep flooding), the termination of these events (carbon dioxide CO2 buildup, greenhouse effect, hydrothermal activity, melting ice positive feedback), the effect of snowball earth on biology (slushball rather than snowball, or thin ice, or photosynthetic life on top of the ice layer), major evolutionary advances made in association with the snowball earths (eukaryote evolution and the evolution of multicellular life- colonies of single cells becoming dependent on each other- kin selection), and lab synthesized multicellular life!
References: Snowball Earth website (including info on paleomagnetic data): snowballearth.org/
snowballearth.org/slides.html
Chapter 12 in Earth System History (4th Edition) by Steven M. Stanley and John Luczaj: amzn.to/3gx6FzI
GEO GIRL Website: www.geogirlscience.com/ (visit my website to see all my courses, shop merch, learn more about me, and donate to support the channel if you'd like!)
0:00 Video outline
0:45 What is snowball earth?
2:32 When was snowball earth?
4:32 What caused snowball earth?
9:50 Evidence for snowball earth?
10:15 Glacial deposit evidence
12:06 Banded iron formation (BIF) evidence
13:25 Cap carbonate evidence
14:38 Carbon isotope evidence
15:42 Boron isotope evidence
16:38 Iridium evidence
18:33 Subsidence and flooding
19:43 Why did snowball earth end?
21:04 How snowball earth affected evolution?
24:37 Recap of snowball earth events
26:02 Bloopers!
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Images:
www.techexplorist.com/snowbal...
www.sci-news.com/astronomy/ste...
www.asianscientist.com/2015/0...
www.quora.com/How-do-we-know-...
www.snowballearth.org/week13.html
cleantechnica.com/2017/09/18/...
mauro04cesar.blogspot.com/201...
theconversation.com/ancient-v...
www.dailymail.co.uk/sciencete...
aasnova.org/2019/10/23/snowba...
takvera.blogspot.com/2014/01/...
www.snowballearth.org/week1.html
astronomy.com/news/2019/04/th...
legacy.earlham.edu/~reedal/Web...
www.snowballearth.org/slides/C...
skepticalscience.com/translat...
www.snowballearth.org/slides/C...
www.snowballearth.org/week11.html
www.slideshare.net/laurenadam...
www.southampton.ac.uk/news/20...
snowballearth.org/end.html
takvera.blogspot.com/2014/01/...
www.geologypage.com/2019/04/wh...
www.egu.eu/news/687/deep-chan...
www.dailymail.co.uk/sciencete...
schoolworkhelper.net/endosymb...
www.wired.com/2012/01/evoluti...
www.slideserve.com/uriel/evol...
www.nsf.gov/news/news_images....
freerepublic.com/focus/f-chat...
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Негізгі бет Ғылым және технология Snowball Earth or Slushball Earths? 3 times Earth was covered in ice | GEO GIRL
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