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Research Supports "Snowball Earth" Hypothesis
u2boy_nl writes, "A new U.S. study finds evidence for 'Snowball Earth,' the hypothesis that the entire Earth was ice-covered for long periods on several occasions, most recently 600-700 million years ago. The icy conditions (Earth's oceans frozen completely with ice more than a kilometer thick) ended violently under extreme greenhouse conditions — snowballearth.org suggests the meltdown could have occurred in as little as 2,000 years. Snowball Earth challenges long-held assumptions regarding the limits of global change. Wikipedia has more on the hypothesis."
Sorry.. couldn't resist it.
Seriously, I wonder if there could be evidence of organisms tolerant of saltier conditions if all that ice left the remaining water saltier.
I always did want to live on Hoth. The big question, however, is whether or not we'll have tontons when the next snowball era rolls around.
Just bring a package of wonton skins along with you on your next perimeter patrol - if things go too badly, gut your tauntaun with your light saber, carve it up a bit, wrap some in a wonton skin, and then use the light saber to boil some water.
Scrumptious!
Those cavemen must have burned a hell of a lot of oil to cause sufficient greenhouse gas to get the earth to warm up again.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
(If you don't know what the Fermi Paradox is, look, Wikipedia!)
One of the possible answers to the Fermi Paradox (which I note doesn't show up in the Wikipedia article) is that life is common in the universe, but the worlds are either hospitable towards the life, resulting in no selection pressure towards complexity, or so hostile that the life totally dies out too often to advance. The general image is of a universe full of oceans full of simple, utterly stable bacteria, which by most standards is still basically lifeless. (We're really interested in other intelligent life, not a universe of little germs.) It has been hypothesized that the best scenario for complex life is a recurring series of disasters that almost, but not quite, kills off life each time, resulting in a strong selection pressure for the requisite complexity to handle such environmental pressures.
Connect that idea with:
The next section of the Wikipedia article mentions the effect this could have had on evolution.
(I find the Fermi Paradox interesting because I believe it is actually by far the biggest problem facing science as a whole; science says life should be plentiful and easy and populating the stars ought to be possible at significant fractions of the speed of light, so where is the life that is doing so? It's easy to become numbed to the problem because it seems somewhat abstract, but it's not. Something is fundamentally wrong with at least one of biology, astronomy, cosmology, sociology, and/or the intersections of those disciplines we don't have names for, and we don't know what.)
This is a fancy way of saying that they have found deposits of submarine rock near the equator that should only be forming in an arctic climate, and which date to the period of 'snowball earth' in question. This sediment has magnetic signatures which signify it formed originally at the equator, in an equatorial magnetic field, and did not simply arrive at the equator after having been formed previously in the arctic.
Please note that we are speaking here of a process of lava cooling, and 'trapping' a fingerprint of whatever magnetic field was present at the time it cooled. That's how these fingerprints are formed and it is a well-known and documented process, and a basis for the current models of magnetic field shift.
Had the magnetic system been different in the past (not a two-pole magnetic field) it would have rendered these results useless, but this article itself explains that there is now evidence that the Earth's magnetic field has always been a dipole (two-pole) field and that these results are correct.
At least, that is my understanding.
occultae nullus est respectus musicae - originally a Greek proverb
I find it amazing that people who believe in something with basically no verifiable proof of existence (i.e. God) have such a tough time believing in something that is so demonstrably happening in front of them.
If ever there was proof of the power of man to delude himself, denying that we have a large and thus-far detrimental effect on climate change would be it.
I can't wait till they get a hold of this one. Regardless of all the other evidence they will use it as a way to slag on evironmentalists, the Kyoto treaty, liberals, democrats, gay marriage, stem cell research and find creative ways to link all of them to terrorism. And champion corrupt corporations as being the benign benefactors of all humanity. This should be fun.
The climate is dynamic. The question is: "are humans having a serious negative impact on the global climate?" And there is a bunch of evidence stacking up saying "yes."
putting the 'B' in LGBTQ+
The upshot of all this is that the researchers hopefully(?) have better evidence of their claims than a few buzzwords which don't really amount to a whole lot. 600 million years is not a long time, geologically speaking - or even evolutionarily-speaking - and I'm not convinced that every necessary process to get from Iceworld to habitable planet could occur in such a short space of time. I could be wrong, but I would need some VERY hard evidence.
What sort of evidence? Well, certainly volcanoes existed back then, and the eventual form lava takes depends on how rapidly it cools. Find me a lava bed in a land mass that would have been tropical at that time (based on current theories of plate movement) and which would not have been connected to open water, but where the rock structure shows clear evidence of cooling of the kind geologists associate with plunging molten lava into ice, AND where that rock also shows clear evidence of prolonged frost cracking. This would not be "solid proof", but it should be very persuasive.
Any other possibilities? Sure. Ice sheets and glaciers form very distinct U-shape valleys. Very very distinct from the V-shape of river valleys. If, indeed, no rivers existed 600 million years ago, only ice sheets, then it follows that any valley of that age or older MUST show the characteristics associated with such ice. Sure, a river may have cut through after, but that can't affect the sides of the valley above it. It can only affect the ground that it was cutting through at the time. The ice sheets, however, will have NOT been level with the ground but will have risen above it. Thus, the ice WOULD have reshaped any river valleys.
Thus, if a single valley, anywhere, shows clear and distinct evidence of cutting by water prior to 600 million years ago, OR if any valley of that time-frame does NOT show evidence of cutting by ice, the theory is falsified. Either will do.
If their claims stand up to the igneous rock test AND the valley test, then I'd be inclined to take the theory more seriously. As it stands, I simply don't see that they've enough to base their claims on. You know when academia is going south when Art Bell's old show could claim greater evidence and a more rigorous analysis. Hey, I happen to think the show has a lot of merit, both in examining controversial and unorthodox thinking that would not otherwise get the hearing it deserves and also as excellent entertainment, but we're in DEEP trouble when the fringiest of the fringe sound more careful, more exact and more scientific than highly-skilled, highly-trained, highly-paid experts.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
"In all seriousness though, how can the Earth being an axial dipole (2 magnetic poles along a single axis) hundreds of millions of years ago suggest an Earth that was covered by up to a kilometer of ice? The Earth is currently in the same magnetic configuration, and there's certainly no indication of an impending super ice age.
Using the same logic, would Geologists in 600 Million years look back on today and say the Earth was covered by ice now?"
The answers to your questions are in the link marked "Snowball Earth" in the post. It is a link to an old (1999) publication about a snowball earth.
Anyway, I took the time to skim over the publication because I, too, wondered how the earth having an axial dipole justified an ice age 600 million years ago. If you don't have the time to read it, I can summarize my findings:
The snowball earth hypothesis is not simply justified by the earth's axial dipole. What is justified by the earth's axial dipole, however, are the measurements of the latitudes found of the rocks that appear to have been present under glaciers.
The way I interpreted the document was that the researchers found samples of rocks that could be geologically determined to have been underneath glaciers at a certain point (approximately 600 million years ago), then they determined the latitude those rocks would have been at at that point in time (since the continents drift, the rock would not be where it is today) based on the rocks' magnetic signatures (assuming the magnetic poles stay near the rotational axis of the earth). Since they found rocks that were under glaciers at low latitudes 600 million years ago, they concluded that glaciers were present at low latitudes (near the equator) at this time and thus must have been present around the globe. As a further explanation of a question that may arise, I believe the rocks were preserved in a manner such that their magnetic signatures would be those from 600 million years ago. (I am not a geologist, so I don't know how it works in particular. If you take the time to read the entire document "Snowball Earth", you might be able to understand better.)
Based on this, geologists 600 million years in the future would not guess that an ice age occurred right now, but would instead correctly guess (well, if it is correct in the first place) that an ice age occurred 1.2 billion years before their time, based on the age of the rocks they would find (which would be 1.2 billion years old).
Now, seeing that this paper was over 7 years old, what makes this whole idea newsworthy? Well, the research mentioned in the article supports the idea that the magnetic field of the Earth has not changed greatly over time, which means that it is safe for scientists to assume the magnetic poles do not travel far from the rotational axis of the Earth, and thus the magnetic signatures of the rocks found should, indeed, accurately represent their former latitude.
Summary of long post: Summary of article: New research supports the idea that certain rocks found where there were glaciers 600 million years ago were, at that time, near the equator, so there must have been glaciers around the world.
The earth runs out of bits and overflows in to negative temperatures.
Once the feedback loop spirals out of control the temperature will drop to -32,768.
Some shred of relevance to the post you are responding to would help too.
The relevance of the article's topic to the current situation is that CO2 as the mediator for precipitous global warming has a precedent. The explanation of how the planet got from Snowball Earth to the Cambrian steambath is based in the same science as the predominant modern theories about the effect of humans turning large quantities of sequestered carbon back into CO2. The theories look a lot more plausible with a very long timescale map that is consistent with the models developed from basic physical facts (like CO2 thermal opacity, he albedo of ice, etc.) and much shorter-time sets of evidence. Snowball Earth looks like an inevitable path to a very dead end except for the fact that it effectively shuts down CO2 sequestration, allowing volcanic release to build levels high enough to counter the self-reinforcing deep freeze with the Greenhouse Effect.
Of course, the problem with this seems to be related to Clarke's Law, that sufficiently advanced technology is indistinguishable from magic (by those who don't understand it.) If you don't understand the science behind modern theories of human-driven global warming, it looks like so much religious bullshit, and more science you don't understand confirming past precipitous warming just looks like more reason to see the whole thing as mystical and beyond understanding. Beyond yours? Apparently so. That's not true for people who do understand the science that is behind both the explanation for why Snowball Earth melted and for why we are now seeing warming that has no precedent in the brief period of civilized history and which runs counter to where natural cycles should be taking the climate.