Skip to comments.Earth's Climate Changes in Tune with Eccentric Orbital Rhythms
Posted on 12/22/2006 11:53:58 AM PST by aculeus
The useless shells of tiny ocean animals--foraminifera--drift silently down through the depths of the equatorial Pacific Ocean, coming to rest more than three miles (five kilometers) below the surface. Slowly, over time, this coating of microscopic shells and other detritus builds up. "In the central Pacific, the sedimentation rate adds between one and two centimeters every 1,000 years," explains Heiko Pälike, a geologist at the National Oceanography Center in Southampton, England. "If you go down in the sediment one inch, you go back in time 2,500 years."
Pälike and his colleagues went considerably further than that, pulling a sediment core from the depths of the Pacific that stretched back 42 million years. Limiting their analysis to the Oligocene--a glacial time period that lasted between roughly 34 million and 23 million years ago--the researchers found that global climate responds to slight changes in the amount of sunlight hitting Earth during shifts in its orbit between elliptical and circular. "Of all the records so far, this is both the longest and, also, the clearest that most of the climatic variations between glacial and interglacial at that time [were] most likely related to orbital cycles," Pälike says.
The researchers pulled specific foraminifera samples from the core and then dissolved the shells in acid. They pumped the resultant carbon dioxide gas into a mass spectrometer and determined exactly what elements comprised the shells. This allowed them to distinguish between shells composed of the relatively lightweight isotopes of carbon and oxygen versus those made with a higher proportion of heavier isotopes.
The isotopes, in turn, reveal a picture of the climate eons ago. Oxygen (O) with an atomic weight of 16 evaporates more readily than its heavier counterpart 18O. Thus, when ice caps form, ocean water bears a higher ratio of the heavier isotope. Because the tiny creatures build their shells from materials in seawater, their calcium carbonate homes reflect the ratio of the two isotopes in the seas of that time. "They are a recorder of how much ice is present on the earth at any given time," Pälike notes.
The same is true for the various isotopes of carbon, 12C and 13C. Because plants preferentially use the lighter isotope, its scarcity is a record of how much life the oceans supported. By matching these isotope ratios to the astronomical cycle--Earth's orbit oscillates between an elliptical and circular path on a roughly 400,000-year cycle--the researchers found that patterns of glaciation and ice retreat followed the eccentricity of our planet's orbitthey report in the December 22 Science.
But the eccentricity of Earth's orbit does not cause that much of a flux in the amount of sunlight the planet receives; that energy budget is much more strongly impacted by variances in the degree ofEarth's tilt toward or away from the sun, which would lead one to expect glaciation to occur on a shorter cycle. Instead, the long times required to move carbon through the oceans apparently acts as a buffer. "Each carbon atom that you put in the ocean stays there for about 100,000 years," Pälike explains. "The climate system accentuates very long periodic variations and dampens shorter term variations."
Earth is currently nearly circular in its orbit and, if this Oligocene pattern were to be followed, would next be headed into another ice age in about 50,000 years. But the amount of carbon dioxide in the atmosphere has reached levels not seen for millions of years prior to the Oligocene. Thus, to get an accurate picture of what the climate might be like in coming years, scientists will have to continue back even farther in history to a period known as the Eocene.
It is already clear, however, that the effects of the carbon released now will affect the oceans for years to come. "Another effect of this residence time of carbon in the ocean is that it takes a long time to flush the system out," Pälike says. "It will take a very long time to go back to the level that existed before a large excursion of CO2. It's not going to be doomsday, end of the world, but a rise in sea level would affect a very large percentage of humankind." Not to mention the shells laid down today on the deep ocean floor of the Pacific.
© 1996-2006 Scientific American, Inc.
1. Out Mayor here accuses people like me who disagree with him of having Eccentric Orbital Rhythms all the time.
2. "Eccentric Orbital Rhythms" makes a really catchy name for a rock band...
An inconvenient truth.
Once again CO2 responds to earth cycles and not the other way around.
Eccentric describes Algore to a T.
How inconvenient for Algore.
On the front: MERRY CHRISTMAS
On the inside: Put out that damn Yule Log. It causes Global Warming
Source: Jay Leno
Except this sediment doesn't settle in nice neat, undisturbed layers. Ocean currents pile them up is some places, sweep them away in others, not to mention earth quakes and other catastrophic events that have happened over the centuries. There are huge deposits of methane ice off the coast of near every continent containing so much energy that it dwarfs that of all the worlds oil deposits. This stuff releases methane and co2 constantly, but for some reason it's never taken into account, nor is it's potential for alternative energy.
Methane Hydrates. Since the 1970s, methane has been discovered in ice lying on, or hundreds of feet below, the deep ocean floor off coastlines. The ice molecules form tiny cagelike structures containing one or more methane molecules. The total energy value of this methane-ice combination, called methane hydrate, may be twice that in all the worlds known coal, oil, and natural gas combined
Water will freeze at slightly warmer temperatures if it is under high pressure and contains dissolved methane. Such temperatures and pressures exist 2,000 feet or more below sea level. There, vast methane deposits are found trapped in ice on and under the deep sea floor, but primarily along coast lines. This methane is escaping into the atmosphere at a rate that would be dangerous if it continued for a million years or so. So obviously it isn't millions of years old. We'd all be dead.
The pacific floor is dished in, and the mid atlantic ridge pushes the sea floor up; it slopes from the coastlines down to a point that's deepest between the mid atlantic ridge and the coastlines. Wanna bet that sediment drifts slowly towards the deepest parts of these formations? Using core samples of this stuff as measurements of the earths age is just plain silly.
There is no way to predict how much is slides towards these centers a year or how many events have effected it, the rate at which this sediment is produced, that it was always constant, etc etc. What about so called continental drift?
Surely that moved it around a lot in 42 million years. Not to mention that we'd all be dead or very stoned from breathing all that methane gas released from the Methane Hydrate ice formations. There is no way that this stuff can be used to determine what the weather was at any point in history because of these underterminable variables.
Heiko Pälike had better head back to the guessing board if he wants to get more grant money. Surely he could have come up with something more believable than this. It can't be that hard.
If we dont oil the drive shaft once a week, Melmacs orbit will start to squeek.
And if we ever have an ocean inversion...well, hold your breath.
I think that depends on how many dinosuars are being supported on the orbital surface vs those that are turning into oil wells below the orbital plain.
Whatever you do, don't flick that bic!
Seriously, I wonder why that stuff isn't being explored as at the very least a very cheap natual gas supply? It would be better to burn it rather than it allowed to go to waste bubbling up and being released naturaly into the atmosphere.
I can only guess that it's being saved for "discovery" at a later time once big oil has extracted all they can from oil.
but doesn't that depend on the rate at which methane is removed from the atmopshere?
However...you make a good point, it is just the next energy supply, bugger all those peak oil idiots.
but doesn't that depend on the rate at which methane is removed from the atmopshere?
I really don't know. I haven't looked into this much other than reading about it once. I can only gather from this that methane is slowly building up in the atmosphere at a rate greater than the other gases to the point where it become toxic to us. Maybe our bodies will adapt and it won't bother us except when we try light up a smoke. Does it escape the atmosphere, or combine with other gasses and become something else? I thought only hydrogen was light enough to escape the earths gravity.
So.....it's not the Sun's fault ......it's the Earth's fault.......or the Solar system........or the galaxy
You mean "scientists" have only now figured out what makes "winter" in northern climates? In fact isn't today the earths max. tilt away from the sun at the north pole? (the shortest day of the year)
(I really don't buy this "shift" in the earths orbit around the sun changing from circular to elliptical and back again either. Maybe it's just the earths wobble stabliizing slowly, makes more sense.)
"Seriously, I wonder why that stuff isn't being explored as at the very least a very cheap natual gas supply?"
It is. At some point on the cost curve of petroleum (equaling about $5 per gal for gasoline) methane hydrate and methane hydride start to look viable as an alternative fuel. There is a huge quantity available, but the research is not being pursued like E85, fuel cells, etc.
That's what I was wondering. "scientists" certainly don't know either. Maybe we should ask Al Gore, He seems to know everything.
You'd think if it just sat there, we'd smell it by now. Pity the first person who gets a wiff of a millions of years old dinosaur fart. "Hog barn days" won't be very pleasant either.
The weather man will have more to do than just guessing at the weather in the future, he'll be guessing at methane gas cloud movements and telling us what the day will smell like.
Further complicating things, Gore's rhythm is Koom Bah Yah.
T'weren't the SUVs then, but the Orbital Cycles.
I wonder what kind of mileage you get with them Orbital Cycles. I'd like to visit Mars and stuff.
They were rolling along making good progress with orbital eccentricity and then they got carbon in their valves and sputtered to a halt.
They should have converted that carbon into methane and released it into the atmosphere.
It always makes me feel better.
Besides, you may think they're "eccentrics," but I say they're a bunch of cranks.
Algore has no science. He has only faith.
Actually, it isn't very steady. If I could find a better seasat photo you can see just how uneven the floor of the oceans and seas are. You can see just how many catastrophic events have occured and no doubt stirred up this stuff at various times, certainly enough to make it impossible to determine what was were and when.
There are many unaswered questions which make it impossible to determine the age of anything that may be on the floor of the Pacific and Atlantic. For example, the grand Canyon is assumed to have been formed by millions of years of errosion. If that's what formed it, wouldnt you expect to find a gigantic river delta where the Colorado River enters the Gulf of California? Its not there. Where did 800 cubic miles of dirt go?
If it's buried under all the magna that sits on top of the actual Pacific floor, which is only assumed to be basalt like the Atlantic ocean floor, (nobody has been able to drill a hole deep enough to find out) it stands to reason anything on the pacific floor would only be as old as the dirt that has piled up from the grand canyon since that event.
Using plate tetonic theory, itself a theory that is in no way free of it's own problems creates even more questions than it answers. Plate tectonics claims a trench forms as a plate dives down into the mantle, a process called subduction. The fact that there is NO distortion as you point out of the horizontal sediment layer in these trenches shows that this can't be what's happening.
If a 30 mile thick plate was sliding into the mantle even only a couple of miles, the friction would be far greater than the rocks strength. We would see much buckling, distortion, breaking and crushing. Yet, there is no horizontal distortion.
Plate tetonic theory suggests earthquakes form where these plates slide under each other , so there would definately be a lot of activty in this area disturbing the sediment greatly. Or, tetonic theory is wrong.
Shallow earthquakes displace the ground horizontally along a fault, and would also cause heat. Since these sediments aren't disturbed or destroyed by heat, these trenches can't be caused a fault line either.
To establish a plausible theory about climate history based on sediments which are impossible to be certain of their age and reliability is a waste of time. certainly not "science" governments enviroment activists should be using to claim the sky is falling, and creating any global warming policy on.
Well, useless to the small animals, which have died. Isn't this the same stuff we use in swimming pool filters, diatomaceous earth?
I'm guessing that it's the limestone of the future.
limestone (lìm´ston´), sedimentary rock composed of calcium carbonate. It is ordinarily white but may be colored brown, yellow, or red by iron oxide and blue, black, or gray by carbon impurities. Most limestones are formed from the skeletons of marine invertebrates; a few are chemically precipitated from solution.
Are you talkin' to me?
No, just an adjective observation from the article.
Uh-oh! I'll get out here ...
(Actually, he was responding to David Biello, but I'm going to be busy making popcorn.)
"2. 'Eccentric Orbital Rhythms' makes a really catchy name for a rock band..."
I think you're confusing them with the 'Electric Light Orchestra' or 'Orchestral Maneuvers in the Dark' (aka OMD, which made some VERY pretty music in the 80's.)
But you're right. What goes around comes around and we haven't had an elegantly named band in a few decades now, LOL!
Only guessing 'cause my track record over millions of years has yet to be established. ;-)
I'm rather partial to "Frankly Scarlet."
I got'cha covered, pal. I'm certified to be older than dirt.
Now that's cute! :)
Husband was listening to a band called "Hinder" the other night,. Being German, I pronounced it "Hine-Der" versus "Hin-Der." LOL!
Stupid marketing IMHO, but they got a luagh out of me. ;)
TCM aired Taxi Driver recently. In the publicity it was mentioned that DeNiro ad-libbed the famous line. A great film.
Methane is the largest component of natural gas, a large percent of our energy resources. As CH4, it doesn't really decompose into anything.
(You do need large quantities of concentrated gas to make use of it though: Diffuse little bits mixed in amidst tons of muck isn't practical to even gather, much less transport and try to use.)
Only problem I see with orbit eccentricities is that they are long-period, very slow transitions: How can you explain a sudden (few hundred year) drop in temperature when the period of change of the earth's orbit (precession for example) is a few hundred thousand years with only a very small total change in sunlight.
Something else caused global climate change in the past.
We can't address today's (possible) global climate change UNTIL we can figure out WHY it changed in the past.
(Having said that, can we recover the gasses from those entrapped methane sources naturally present in the Superdome after a chili and beer cookoff Louisiana style?)
Let's have the truth. No more political agendas. If the media would just report the facts I would make up my mind without their help. When they "report" in such as way as to try to convince me of something, I don't believe them.
Very perceptive. In truth, we can examine orbital eccentricities, Solar variations, and possibly even Galactic rotations as predictable variants, but there are also unpredictable factors which can affect global climate.
Very widely spread forest fires, vulcanism, and even uncharacterized animal or plant climax populations could have had randomizing factors at critical times in Earth's wobble-dance.
Climatological profiles and computer models can not take advatage of these possibilities, so not every excursion is explicable. Sometimes things just happen, like meteoric impacts.