Earth's climate change 20,000 years ago reversed the circulation of the Atlantic Ocean

Nov 03, 2010

An international team of investigators under the leadership of two researchers from the UAB demonstrates the response of the Atlantic Ocean circulation to climate change in the past. Global warming today could have similar effects on ocean currents and could accelerate climate change.

The Atlantic Ocean circulation (termed meridional overturning circulation, MOC) is an important component of the climate system. Warm currents, such as the , transport energy from the tropics to the subpolar North Atlantic and influence regional weather and climate patterns. Once they arrive in the North the currents cool, their waters sink and with them they transfer carbon from the atmosphere to the abyss. These processes are important for climate but the way the Atlantic MOC responds to climate change is not well known yet.

An international team of investigators under the leadership of two researchers from the UAB now demonstrates the response of the Atlantic MOC to in the past. The new research results will be published on 4 November 2010 in the international front-line . The research project was led by Rainer Zahn (ICREA researcher) and Pere Masque, both of the UAB at the Institut de Ciència i Tecnologia Ambientals (ICTA) and Department of Physics. With collaborators at the universities of Seville, Oxford and Cardiff (UK) they investigated the distribution of isotopes in the Atlantic Ocean that are generated from the natural decay of uranium in seawater and are distributed with the flow of deep waters across the Atlantic basin. The young investigator Cesar Negre studied the natural abundance of these isotopes in the seafloor sediments 2.5 km deep in the South Atlantic and achieved a PhD degree in the Environmental Science and Technology doctoral programme at ICTA.

The study shows that the was very different in the past and that there was a period when the flow of deep waters in the Atlantic was reversed. This happened when the climate of the North Atlantic region was substantially colder and deep convection was weakened. At that time the balance of seawater density between the North and South Atlantic was shifted in such a way that deep water convection was stronger in the South Polar Ocean. Recent computer models simulate a reversal of the deep Atlantic circulation under such conditions while it is only now with the new data generated by UAB scientists and their colleagues from Seville and the UK that the details of the circulation reversal become apparent. This situation occurred during the ice age 20,000 years ago. Although this was far back in time the results are relevant for our climate today and in the near future. The new study shows that the Atlantic MOC in the past was very sensitive to changes in the salt balance of currents. Similar changes in seawater salt concentration are expected to occur in the North Atlantic in the course of climate warming over the next 100 years. Therefore the data to be published in Nature offer the climate modelling community the opportunity to calibrate their models and improve their capacity to predict reliably future ocean and climate changes.

Explore further: Fall in monsoon rains driven by rise in air pollution, study shows

Provided by Universitat Autonoma de Barcelona

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R_R
1 / 5 (4) Nov 04, 2010
Perhaps the Atlantic circulation was sensitive to 50 mile wide crust piercing meteors, not salt.

The currents changed direction
The continents thier elevation
The planet stopped rotation
The poles a relocation
An Ice Age explanation
A Science of castration

"Message from the Ancients"
R_R
1 / 5 (3) Nov 05, 2010
As a follow up, I'm of the understanding that the current circulation of oceans, storms and even toilets all spin one way in the northern hemisphere and the other in the southern hemisphere. Can some one here explain how this might change if the planet stopped its rotation and then started up in the opposite direction. Would the ocean circulation (and toilets) change direction of circulation, just as this report above indicates did happen.
thermodynamics
5 / 5 (4) Nov 05, 2010
R_R: We would have a lot more in the way of problems than the direction the oceans were spinning if the earth changed spin directions. In stopping and re-accelerating the forces on continents and oceans would rip them apart. There would be no more ring of fire, there would be a planet of fire. I would be surprised if anything on the surface of the planet survived such a catastrophe.

In general there are forces called the Coriolis effect you can read at wikipedia:

http://en.wikiped...s_effect

Which affects currents, winds, and other moving fluids. However, currents and winds are more complex than that since they have many other forces working on them including pressure, density gradients, etc. The Coriolis is pretty weak and needs the right systems to prevail.

Your disaster scenario would be a terrible end to most(if not all) of life on earth.
R_R
1 / 5 (3) Nov 05, 2010
Thermo, as to your convictions,it is possible to survive Pole Shift, we did 10500 BC. No offense, but you have accepted speculation as fact. As to fire, Dr. Firestone has shown N. America was incinerated. As to flood, well you know the tales. I have seen countless times Pole Shift better explains evidence but is not considered. Scientists know where thier breads buttered.

Let me just say there were survivors and they were some kind of smart. Listen to them and not the Bullshit you were taught!
thermodynamics
5 / 5 (3) Nov 06, 2010
R_R: It does surprise me when I run into someone who is ignorant enough to confuse stopping the rotation of the earth with swapping magnetic poles. They are two completely different animals. In stopping the rotation of the earth you would have to stop all of the angular momentum. What that means is that the angular momentum would be turned into heat - ripping the continents apart and sloshing the oceans across what was left of the continents.

That is completely different from the poles migrating (which they are always doing) and even switching positions. The switch of magnetic poles is electromagnetic in nature and does not change the rotation of the earth. So, you have mixed up the concept of pole-shift with change of rotation. I think you really need to do some reading on the difference between these two things. One (changing rotation) destroys large sections of the earth. The other (swapping poles) happens often.
R_R
1 / 5 (3) Nov 06, 2010
Thermo, it surprises me when someone is ignorant enough to use the word ignorant. When did I ever say magnetic pole? You might find I'm a great deal more more informed then you think I am if you were to open your mind. So again.

This planet slowed to a stop and then started up in the opposite direction but at 30 degrees off its original axis. 10500BC. Pole shift and rotation reversal. Measured and recorded by eye witness survivors. Or lay in your bed of hay.
thermodynamics
5 / 5 (2) Nov 06, 2010
R_R: OK, now this is getting interesting.

Do you have any references to the event you are talking about?

Are there any measurements?

Can you point us at a paper?

I will explain my issues with what you have had to say.

1) You say this was measured and reported by survivors. I am not aware of any measurements or reports from 10,500 BC about anything - let alone the stoppage of the rotation of the earth in its tracks.

2) Angular momentum is a measurable and computable property. When angular momentum is stopped it requires energy (try grabbing a spinning top to stop it). An entity then requires energy to start back up again (the top you stopped has to be spun back up). Where did the energy come from?

Please give references.
GSwift7
3 / 5 (2) Nov 10, 2010
lol Thermo, maybe her only source of news is the National Inquirer or The View?

There are a few questions/problems I have with this press release (of course). Once again the question of the chicken and the egg must be answered. Changes in salinity, climate, circulation, etc. All very difficult to sort out in terms of what happened first and what was a cause and what was an effect, especially when they kinda blend. The statement in the above article about how 'sensitive' the ocean is to changes in air temperature seems a bit suspect to me. I would be more inclined to believe that when you look at the pair of the ocean and the air, it's probably going to be the state of the ocean that has more influence over the combined state of them both.
thermodynamics
5 / 5 (1) Nov 11, 2010
GSwift7: I am going to agree on your observation that the sea probably has more influence. However, there are other issues that have more influence yet, and both can be changed as such. For instance, the influence of the sun is number 1. If there were any changes in input (such as receding ice) the sun interacting with the open ocean instead of the ice would influence all three (ice, ocean, and atmosphere). It would not take much albedo change. Then everything is happening at once with feedback from water vapor. So I would be hard pressed to say anything lead and what the great influence was. It is too complicated to simplify as they did in the article. Of course, R_R will probably have it all thought out and I am really interested in the references. I think we will all have a lot to learn when they show up.
GSwift7
3 / 5 (4) Nov 11, 2010
"It is too complicated to simplify as they did in the article"

Which makes me ask if the problem is the article, the research, the spokesperson, the editor(s), or even just an error/oversight.

What really scares me about R_R's posts is that those kinds of beliefs aren't uncommon. The average person, even in the US, doesn't know much about science. Ask 10 people what kind of sound does a laser make, or what color is an infrared laser, for instance. Heck, the average office worker probably can't explain potential energy, momentum or work. R_R is a good example of that, and he's probably a high school graduate, but it's clear that he's not educated enough to know the difference between "then" and "than" as demonstrated here: "You might find I'm a great deal more more informed then you think I am "

that's common these days. My own 14 y/o daughter mixes up "whether" and "rather" all the time.
GSwift7
1 / 5 (1) Nov 11, 2010
"It would not take much albedo change"

I'm not going to accept that statement actually. The poles only receive a small amount of sunlight you know, and much of that reflects off the surface due to incident angle, regardless of whether it's water or ice. The vast majority of solar input happens in equatorial lattitudes. Albedo change at the poles is a drop in the bucket compared to all the other components in the system globally. At the poles I expect wind speed dominates albedo in terms of it's effect on air temp.
GSwift7
1 / 5 (1) Nov 11, 2010
"At the poles I expect wind speed dominates albedo in terms of it's effect on air temp"

I should clarify that. I mean that fluctuations in wind speed and pressure should have a larger effect on air temp at the poles, due to evaporation and such, than the difference between the albedo of ice versus water there.
GSwift7
1 / 5 (1) Nov 12, 2010
Realistically, if the circulation of the Ocean currents were as vulnerable to upset as some alarmists would have you believe, then the seasonal cycle of polar melt and thaw would wreak havock on the currents. We don't observe that, so I'm inclined to say that the currents are more stable than they would have us believe in articles like this one, which hint at impending global doom at the hands of mankind.
R_R
1 / 5 (4) Nov 12, 2010
Thermo, I do not have regular access to the net but can answer now. The 500 km wide craters (force) that brought about these changes are right in front of you at lower right Hudson Bay and Great Lakes. It utterly amazes me how highly educated people are so blind and can be so easily manipulated to the point they unquestionly accept, no defend, such complete and utter rubbish no matter what evidence to the contrary is placed in front of them. By the way, ancient myth is cramed with reference to this event.

Read 'Message from the Ancients", then show me where I'm wrong, although I'm sure you will carry on defending your masters lies. Ba Ba
thermodynamics
5 / 5 (1) Nov 14, 2010
R_R: The 500 km wide craters sound pretty impressive. In fact, I have heard of them before. However, they will have almost zero effect on the rotation of the earth. Here is a URL for an on-line system for calculating the effects of astronomical collisions.

http://impact.ese...Effects/

You can put in sizes and densities of impactors and see what diameter crater they produce. I did that for 500 mile diameter craters and the result is that there is almost no effect on the rotation of the earth (lengthening of the day). Part of that is that the rotational energy of the Earth is approximately 2.14x10^29 J. That is a lot of energy.

Here is a site with some smaller craters and their energy of colossions.

http://www.enotes...t-crater

they give a 62 mile crater needing about 4.6x10^22 J.

I will continue this in the next comment (continued)
thermodynamics
5 / 5 (1) Nov 14, 2010
The problem is that you do not understand the amount of energy needed to stop the earth and then have it startup going the other way. You seem to think of the earth as this rigid body that, when hit with an asteroid, moves as a solid to respond to the asteroid. What you do not seem to understand is that at the velocities of the impact, the energy of the impact is greater than the molecular bonds holding the rock together so it flows like a liquid. Those ferocious impacts that leave 500 mile craters do not slow the earth much at all even if the impact is at an optimal angle. The reason is that on top of energy transfer you have to change angular momentum. If you do the calculations you will find that stopping the earth from rotating will cause the oceans to continue to move (since they are not as viscous as the rock) while the rock slows. Likewise, the atmosphere will continue on being slowed much less than either the oceans or rock. (continued)
thermodynamics
5 / 5 (1) Nov 14, 2010
Continued: The result is that the solid rock will flow like a fluid and will heat to thousands of degrees sterilizing the planet. The wind will take days - weeks to couple to the planet. The ocean will take days to couple but it will evaporate due to the heated rock at the surface. The impactor you would need would be capable of much more damage than a 500 mile crater. You have been fed a line that seems to say that the planet can (and has) been stopped and sent spinning in the other direction by an impact that left something on the planet alive. Do the math. It is relatively straight forward. All you need is the earth's angular momentum and rotational energy. You would need a text on rock mechanics. You can use the on-line calculator I mentioned above. Just match the impact and angle to stop the earth. Find out how much energy that is and compare it with the amount needed to melt the crust. Bingo-you have an answer.
thermodynamics
5 / 5 (1) Nov 14, 2010
Continued: R_R: I just went through and did some of my own calculations to see what would be needed. The rock asteroid would have to be about 2,480 miles in diameter with a density of about 3000kg/m^3. I used an impact velocity of 30 km/sec. My impact angle was 30 degrees. The resulting crater would be about 15,000 miles in diameter (not your 500 mile craters). Under those conditions the earth's surface would be 18.3% melted. The oceans would be evaporated. It could change the length of the day by about 57 hours with the right angle. In fact, they also say that this size collision will not take place over the lifetime of the planet. If it did take place it was during the great bombardment or the formation of the moon. Please realize that the event you are talking about cannot happen and has not happened no matter what you have read. Have you bothered to make the calculations yourself to see you are being spun a yarn?
R_R
1 / 5 (4) Nov 18, 2010
Thermo, I do not know how to convince you these changes did occurr and you are the one being hoodwinked, but doing my best. Thankyou for your serious response. The ancients recorded these impacts and Pole Shift and state this occurred 10500 BC (with star positioning) although it is possible something else occurred as well such as a close flyby of an enormous body (which may also be recorded but not sure at this time). I certainly do not trust your calculatios though given they originate fron our selfish pseudo science that strives to cover up this event. The core evidence in every case backs my position, just no scientist dare say it.
R_R
1 / 5 (4) Nov 18, 2010
Thermo, the most glaring example is the fact that up to 12000 years ago much of North America was covered with mile thick ice while directly on the opposite side of todays pole (and very close to it) in Siberia and Alaska there was no ice cover. In fact in these areas millions of frozen Elephant and Rhino bones have been found showing it was quite pleasent along the arctic ocean coast duing this so called Ice Age. Sciences explanation for this and so many other things is such a joke, it baffles me how they get away with it.
thermodynamics
5 / 5 (3) Nov 18, 2010
R_R: Let me try to understand your stance. Are you convinced that modern science is made up of people who make things up to push a view that is politically correct?

Have you ever taken a physics course? The concept of angular momentum is part of a first course in physics and has been known since the Greeks and quantified by Newton's time. Are you saying that the concept of angular momentum is a lie?

Thanks for the response.
R_R
1 / 5 (4) Nov 18, 2010
Thermo, modern science is concerned with money and power, no different then Wall Street. Modern scientists know better then to rock the boat. For instance, no scientist today would dare say Eratic boulders could have been blasted to thier positions, not moved by ice, even though this theory is very plausible (indeed is the reality). Ask yourself why this is. This is a very dangerous problem, but my expierience is that few see it or even care.
thermodynamics
5 / 5 (1) Nov 18, 2010
R_R: You are just not getting it. "Erratic boulders" would not be "blasted to their positions" they would be molten globs that are blasted around the Earth. Much smaller impacts have left much bigger footprints. You are postulating a recent huge event that left almost no footprint around the world. If there were really that large of an impact it would have blasted ejecta into orbit and melted a huge part of the Earth. There is no such sign of anything like that happening in the past few tens-of-millions of years.
R_R
1 / 5 (5) Nov 18, 2010
Thermo, the evidence is everywhere but as I suspected I'm unlikely of getting through with you. I could go on and on giving examples but you have a closed mind and just say no no no. These impacts blasted rock out like any explosive would such as at a mine site demolition. Countless millions of boulders lie apon the groud where they should not be, just because you were taught "molten globs" and "melted Earth" senerios does not mean the stories told, in the end this is just someones speculation. So open your eyes and stop feeding from the information trough.