From Harvard University Science: Scientists find signs of ‘snowball Earth’
Research suggests global glaciation 716.5 million years ago
Steve Bradt
Harvard Staff Writer
Geologists have found evidence that sea ice extended to the equator 716.5 million years ago, bringing new precision to a “snowball Earth” event long suspected of occurring around that time.
Led by scientists at Harvard, the team reports on its work in the latest edition of the journal Science . The new findings — based on an analysis of ancient tropical rocks in remote northwestern Canada — bolster the theory that the planet has, at times in the past, been covered with ice at all latitudes.
“This is the first time that the Sturtian glaciation [the name for that ice age] has been shown to have occurred at tropical latitudes, providing direct evidence that this particular glaciation was a ‘snowball Earth’ event,” said lead author Francis A. Macdonald, an assistant professor in Harvard’s Department of Earth and Planetary Sciences. “Our data also suggests that the Sturtian glaciation lasted a minimum of 5 million years.”
The survival of eukaryotic life — organisms composed of one or more cells, each with a nucleus enclosed by a membrane — throughout this period indicates that sunlight and surface water remained available somewhere on the surface of Earth. The earliest animals arose at roughly the same time, following a major proliferation of eukaryotes.
Even on a snowball Earth, Macdonald said, there would be temperature gradients, and it is likely that ice would be dynamic: flowing, thinning, and forming local patches of open water, providing refuge for life.
“The fossil record suggests that all of the major eukaryotic groups, with the possible exception of animals, existed before the Sturtian glaciation,” Macdonald said. “The questions that arise from this are: If a snowball Earth existed, how did these eukaryotes survive? Moreover, did the Sturtian snowball Earth stimulate evolution and the origin of animals?”
“From an evolutionary perspective,” he added, “it’s not always a bad thing for life on Earth to face severe stress.”
The rocks that Macdonald and his colleagues analyzed in Canada’s Yukon Territory showed glacial deposits and other signs of glaciation, such as striated clasts, ice-rafted debris, and deformation of soft sediments. The scientists were able to determine, based on the magnetism and composition of these rocks, that 716.5 million years ago they were located at sea level in the tropics, at about 10 degrees latitude.
“Because of the high albedo [light reflection] of ice, climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over,” Macdonald said. “So our result implies quite strongly that ice would have been found at all latitudes during the Sturtian glaciation.”
Scientists don’t know exactly what caused this glaciation or what ended it, but Macdonald says its age of 716.5 million years closely matches the age of a large igneous province stretching more than 930 miles from Alaska to Ellesmere Island in far northeastern Canada. This coincidence could mean the glaciation was either precipitated or terminated by volcanic activity.
Macdonald’s co-authors on the Science paper are research assistant Phoebe A. Cohen; David T. Johnston, assistant professor of earth and planetary sciences; and Daniel P. Schrag, Sturgis Hooper Professor of Geology and Professor of Environmental Science and Engineering, all of Harvard. Other co-authors are Mark D. Schmitz and James L. Crowley of Boise State University; Charles F. Roots of the Geological Survey of Canada; David S. Jones of Washington University in St. Louis; Adam C. Maloof of Princeton University; and Justin V. Strauss.
The work was supported by the Polar Continental Shelf Project and the National Science Foundation’s Geobiology and Environmental Geochemistry Program.
jorgekafkazar (20:59:35) :
Sheffield BM(Smallz79) (19:36:10) : “What really happen [sic] was a world wide flood, in which water came down from the sky and bursted [sic] out of the surface of the Earth all at once. This caused a simultanious [sic] and (comparered [sic] to millions of years) instantaneous movement of all land masses to were [sic] they are presently. This is all completely verifiable, you just have ask the right scientists. Which by the way the Earth is still holding all that water somewhere.”
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I’ve read something like this before….and i’m not going to reveal my source.
‘…………..the Heavens existed and the earth was formed out of water and by water. By these waters also the world of that time was deluged and destroyed….’ (Pete)
Also, regarding conversion of CO2 to O in early earth…
‘….. And ___ said, “Let there be an expanse between the waters to separate water from water.” So ___ made the expanse and separated the water under the expanse from the water above it. And it was so. ___ called the expanse “sky.” And there was evening, and there was morning—the second Age/Epoch. And ___ said, “Let the water under the sky be gathered to one place, and let dry ground appear.” And it was so. ___ called the dry ground “land,” and the gathered waters he called “seas.” And ___ saw that it was good. Then ___ said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds.” And it was so. The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And ___ saw that it was good. And there was evening, and there was morning—the third Age/Epoch………..’
So, the first living thing according that big book end are vegetation, trees and seed-bearing plants. Ergo-conversion of CO2 to Oxygen. Just wanted to make one aware that this is in there; an itch i had to scratch. My apologies to anyone if this is offensive and understand fully all the arguments why this shouldn’t be here. This is an FYI courtesy posting. Thx
Joe (05:03:57) :
Perhaps the turbulence it causes as the planet goes “whoosh” past the camera has something to do with it…. I canna slow her down cap’n….
Ref – rbateman (21:41:46) :
“The Snowball Earth formation:
How about a really big asteroid hitting Venus..”
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I have a feeling we’ll never know:-)
Ref – Robert Kral (22:41:33) :
“attempting to explain the behavior of a highly complex system in terms of a single variable is an exercise in futility and self-delusion.”
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Scientists are people:-)
Ref – James Mayo (23:55:43) :
“..next time you feel like screaming, try thanking an alarmist for ringing the bell at the free market of ideas and may the best theory stand up to the scrutiny.”
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True, but we’re rarely able to do that when we get truly emotional:-)
Footnote: We know so little and we feel so much.
I apologize for being a bit off topic, but with all the reference to CO2, I have had a nagging thought for a week or so… With the concern over fossil fuel, we think it takes 100s of thousands or millions of years to make from old organic material. Okay, so where is all the raw/partially processed fossil fuel? That should be the bulk of what we find if there is indeed an organic component to the process. Lacking an organic component, is there such a thing as ‘fossil’ fuels? There were reports a few years ago of oil wells pumped dry in the past, refilling with oil, thought to be from deeper in the crust. I just can’t rectify zero reports of raw/partially processed oil discovered, with the amount of oil we do find, and then assume it is organic!?
This has references from 2004:
http://www.wnd.com/news/article.asp?article_id=38645
It seems simple to me. Jan Veizer,and Nir Shaviv have written papers that have established a correlation between average temperatures and cosmic ray flux for the past several hundred million years. Svensmark’s theory predicted just such glaciation even though CO2 concentrations were more than ten times higher than they are now. The latest studies seem to confirm Svensmark’s theory and put another nail in the CO2 driven warming thesis.
Charles, others,
The current continental drift theory like the current AGW theory is full of holes. Any time you hear “consensus” you should know something is wrong, someone is trying to defend their life’s work. Current continental drift theory claims spreading occurs in the Atlantic and subduction occurs in the Pacific. Why? Why no subduction in the Atlantic? Because it is too easy to see that Africa nestles up against South America like a perfect fitting puzzle piece. The same puzzle pieces fit in the Pacific, but it is hard to see because the Pacific is so big. If the puzzle pieces fit, you must acquit, it means spreading, not subduction.
Fish fossils from > 200mya are found on continental plates in places like Utah. So there were “shallow seas” on the continental plates, but no oceans back then.
I’m going to drop this now as it seems pretty off topic.
Snowball Earth whether fully realized or not, just shows that Gaia is not necessarily nice. If earthquakes and tsunamis aren’t enough to convince the Believers, then ice ages should do the trick.
Personally, in my time in the lab, I’ve never seen the universe try for “statically stable”. Dynamically stable, yes, but not statically stable. Oscillations and fractal fluctuations are the order of the day everywhere one looks. If it’s that way on the subatomic scale, the atomic scale, and micro scale, why should it be different at macro scale?
Personally, I think our climate is a complex interaction between Sun, cosmic rays, the Moon, and our oceans.
Kevin (19:55:51) :
How are they so sure that a stop in the Ocean CO2 cycle supposedly leading to a buildup of atmospheric CO2 due to volcanic offgassing caused a ‘hothouse Earth’ effect?
Because Al Gore said so!
It’s amazing to me that the scientists related all of the offgassing of volcanoes to C02. They completely left out sulfur dioxide and a host of other more prominent gasses.
“Okay, so where is all the raw/partially processed fossil fuel? That should be the bulk of what we find if there is indeed an organic component to the process.”
It is called “bituminous shale” and is indeed vastly more common than oil.
JMANON (02:08:24) :
The references from CO2 in the discussion do not arise from the paper itself, but from other sources like Wikipedia and other papers on snowball earth which specifically do reference CO2 as the primary agent that forced the end of the glaciation of the entire globe. It seems to me that it is appropriate to bring this into the discussion as this would be the information most likely fed to the media – and certainly fed to anyone casually looking up the phenomenon (i.e. Wikipedia) – and which I encountered in a book I am reviewing on microbiology, which discusses both the roles of volcanic CO2 and microbes in ending this extreme glaciation.
There are, then, two issues here: 1) is snowball earth a plausible theory based on sound geological evidence? – and – 2) what plausible mechanisms could have caused and ended this state?
D. Patterson (07:31:12) :
Perhaps the turbulence it causes as the planet goes “whoosh” past the camera has something to do with it…. I canna slow her down cap’n….
Good point.
But if it were to be a close hit, then it would pull some of the atmosphere away and create massive wind that would erode the land masses.
It could have also been a near miss from a solar flare. This would have heated the gases in the atmosphere triggering this planets defences which is to change the salinity in the oceans. The atmosphere is very elastistic and any increase in pressure (heat can change a gases density and movement(resonating vibration))exerts out at the atmosphere. It also changes the density of the atmosphere which would change the speed the atmosphere is moving at differing layers.
The holes are in the arguments which are ignorant or ignore basic facts and mechanisms explaining the continental drift. For example, you ask, “Why no subduction in the Atlantic?” Answer, there are subduction zones in the Atlantic Ocean basins. Consequently, your question and dependent assumptions are invalid. In anticipation of a possible followup question you may have, “Why are there not as many subduction zones in the Atlantic Oceans as there are in the Pacific Ocean?” Answer, it has to do with the nature of the formation of the Atlantic Ocean basins, various mechanisms like retreating subduction zones, tectonic uplift in the oceanic basin, and a number of other factors which differ in effect between the Atlantic and Pacific Oceans.
Don’t let the bafflegabbers fool you. Continental drift is quite real.
Ref – Al Gore’s Brother (10:20:38) :
Kevin (19:55:51) :
“How are they so sure that a stop in the Ocean CO2 cycle supposedly leading to a buildup of atmospheric CO2 due to volcanic offgassing caused a ‘hothouse Earth’ effect?
“Because Al Gore said so!
“It’s amazing to me that the scientists…”
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People, including most ‘psyentists’ –and even a number of Scientists– have to (aka ‘must’) believe in something other than themselves. We know so little and want to know so much. When we get a snippit of truth we generally tend to build a story (aka ‘rational explaination’) about how it happened.
M. Simon (02:22:39) :
Dave Wendt (20:34:40) :
Am I correct in assuming that the illustration was not part of the PR, but added here.
The illustration was part of the PR.
It’s not included in the linked statement posted at Harvard Science or at any of the links in the statement. The graphic includes this link to its origin at the University of Georgia.
From the University of Georgia Tutorial on Terrestrial Atmosphere: http://www.physast.uga.edu/~jss/1010/ch10/ovhd.html
Perhaps the mods could clarify the situation.
6 03 2010 Joe (05:03:57) :
The near side of the moon has more craters than the far side. Why? Best guess is that the earth’s gravity attracts astroids, bending their path so that they more likely to collide with the moon, on the side facing the earth. Gravitic lensing, sort of.
Glacial ice may have extended to the equator at one time, but marsupial fossils are found in the mountains of Antarctica. Has no one ever heard of Plate Tectonics or is it to be presumed kangaroos like ice for dinner.
At the other end of the scale crocodiles roamed the Arctic 55 million years ago! And all these Warmists worry about a little warming which has happened time and time again.
http://www.newscientist.com/article/mg19826611.200-when-crocodiles-roamed-the-arctic.html
What do marsupials in Antarctica less than 2.5 million years ago have to do with the proposed Snowball Earth events of the Sturtian-Varangian Ice Age/s and the Huronian Ice Age 600 million to 2,400 million years ago (2.4 billion years ago)? You’re talking about protozoan lifeforms at the time of the Snowball Earth events with vertebrate lifeforms still in the far far distant future.
Al Gore’s Brother (10:20:38) :
It’s amazing to me that the scientists related all of the offgassing of volcanoes to C02. They completely left out sulfur dioxide and a host of other more prominent gasses.
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It would be less amazing if you looked at how actual scientists treat volcanic eruptions in their climate models:
http://earthobservatory.nasa.gov/Features/GlobalWarming/global_warming_update4.php
Volcanic particles, volcanic gases pumped high into the atmosphere where they interact with water vapor to form a reflective shade of aerosol particles…
The above example is climate modeling of the Mt. Pinatubo eruption in 1991 in the Phillipines. The global circulation model closely matched the observed cooling of about four years duration.
What about the known brightening of the sun and axis tilt? I recently heard a prediction that the continued brightening of the sun (10%/billion years) will fry the Earth, given everything remains the same, within 500 million years. Take that back, put in a different continental configuration and … you don’t need CO2. Volcanic Ash covering glaciated areas near the equator? … another proven ice melter at marginal temps.
Whatever. I find Snowball Earth evidence amazing even though the forcing mechanisms suggested here and in a BBC documentary and others espousing this theory play too hard for anthrocentric sympathies. I guess its too much to ask for them for ‘Just the facts, Maam’. Its hard enough, given the time scales, to even scratch considering what we, as a species, might be before any of this is meaningful to us in general. Would ‘The Borg Collective’ care?
How do you figure the near side with its extensive maria has more craters than the far side with its extensive cratering in the older highlands?
len (15:37:23) :
Some estimates indicate a 10 percent increase in Solar luminosity in about 1.1 billion years or 1100 million years. By that time the atomosphere and its water vaopr are being stripped from the Earth by the Sun, and by 4.4 billion or 4400 million years the Earth’s hydrosphere has been vaporized and is being stripped from the Earth and blown by the Solar Winds to the outer reaches of the Solar System. Since the Sun is losing mass at an exorbitant rate, the new orbits of the Earth take it to 1.2AU and !.4AU farther away from the Sun near the present day orbit of Mars.
At 5.56 billion years or 5500 million ears, a member of the WWF lands on the tortured Earth’s bleak landscape long enough to spray paint a message on a nearby boulder where Colorado Springs once stood saying ” I told you so!” After the WWF activist leaves, a prospector survey team rolls up to the boulder in a special purpose survey vehicle. A prospector gets out in his environmental suit and spray paints underneath the first message, “What took you so long, Al baby?”
D. Patterson (07:27:17) :
Tenuc (01:26:40) :
Trying to discover what happened millions of years ago reminds me of the old Zen problem of how to get a goose out of a bottle without injuring the goose or breaking the bottle?
Things were very different then. Without sufficient factual evidence of what was happening 716.5 million years ago and the ‘context’ of the assumed event, the proposed hypothesis is mere speculation.
“Some elements of the hypothesis are and must inherently be speculative. Nonetheless, substantial parts of this hypothesis and similar hypotheses are supported by a large array of well established factual evidence.
The computer models show that once 50% of the Earth is covered in ice, the remaining oceans will ‘enevitably’ freeze over. However, these models are working with a limited amount of data, some of which is of dubious quality, and many assumptions are made regarding conditions on Earth some 0.75m years ago.
We know that there have been many periods of glaciation, some very long, but it is still speculation to posit a that a completely ‘snowball Earth’ actually happened.
The following quote from the article by the lead author, Francis Macdonald, indicates that the new evidence supports the hypothesis, but does not give conclusive confirmation.
“Because of the high albedo [light reflection] of ice, climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over,” Macdonald said. “So our result implies quite strongly that ice would have been found at all latitudes during the Sturtian glaciation.”
“Scientists don’t know exactly what caused this glaciation or what ended it, but Macdonald says its age of 716.5 million years closely matches the age of a large igneous province stretching more than 930 miles from Alaska to Ellesmere Island in far northeastern Canada. This coincidence could mean the glaciation was either precipitated or terminated by volcanic activity.”
Fred Souder (04:59:58) :
I dismissed the AGW hypothesis way back in the 70’s although my background is more in electro-mechanical engineering.
I did a sort of “that’ll never fly” & never considered it again until I suddenly found out that some people thought it would fly.
Sometime last year I hypothesised that the North Pole was one of the thermostats of the Earth because ice loss would allow extra heat to escape to the atmosphere & thence to space.
Your posting seems to confirm what I thought.
Do you have a reference I can use please?
DaveE.