Planet Earth may have 'tilted' to keep its balance

[C1ay]

Imagine a shift in the Earth so profound that it could force our entire planet to spin on its side after a few million years, tilting it so far that Alaska would sit at the equator. Princeton scientists have now provided the first compelling evidence that this kind of major shift may have happened in our world's distant past.

 

lefthttp://hypography.com/gallery/files/9/9/8/polar_wander_thumb.jpg[/img]By analyzing the magnetic composition of ancient sediments found in the remote Norwegian archipelago of Svalbard, Princeton University's Adam Maloof has lent credence to a 140-year-old theory regarding the way the Earth might restore its own balance if an unequal distribution of weight ever developed in its interior or on its surface.

 

The theory, known as true polar wander, postulates that if an object of sufficient weight -- such as a supersized volcano -- ever formed far from the equator, the force of the planet's rotation would gradually pull the heavy object away from the axis the Earth spins around. If the volcanoes, land and other masses that exist within the spinning Earth ever became sufficiently imbalanced, the planet would tilt and rotate itself until this extra weight was relocated to a point along the equator.

 

"The sediments we have recovered from Norway offer the first good evidence that a true polar wander event happened about 800 million years ago," said Maloof, an assistant professor of geosciences. "If we can find good corroborating evidence from other parts of the world as well, we will have a very good idea that our planet is capable of this sort of dramatic change."

 

Maloof's team, which includes researchers from Harvard University, the California Institute of Technology and the Massachusetts Institute of Technology as well as Princeton, will publish their findings in the Geological Society of America Bulletin on Friday, Aug. 25.

 

True polar wander is different from the more familiar idea of "continental drift," which is the inchwise movement of individual continents relative to one another across the Earth's surface. Polar wander can tip the entire planet on its side at a rate of perhaps several meters per year, about 10 to 100 times as fast as the continents drift due to plate tectonics. Though the poles themselves would still point in the same direction with respect to the solar system, the process could conceivably shift entire continents from the tropics to the Arctic, or vice versa, within a relatively brief geological time span.

 

While the idea that the continents are slowly moving in relation to one another is a well-known concept, the less familiar theory of true polar wander has been around since the mid-19th century, several decades before continental drift was ever proposed. But when the continents were proven to be moving under the influence of plate tectonics in the 1960s, it explained so many dynamic processes in the Earth's surface so well that true polar wander became an obscure subject.

 

"Planetary scientists still talk about polar wander for other worlds, such as Mars, where a massive buildup of volcanic rock called Tharsis sits at the Martian equator," Maloof said. "But because Earth's surface is constantly changing as the continents move and ocean crustal plates slide over and under one another, it's more difficult to find evidence of our planet twisting hundreds of millions of years ago, as Mars likely did while it was still geologically active."

 

However, the sediments that the team studied in Svalbard from 1999 to 2005 may have provided just such long-sought evidence. It is well known that when rock particles are sinking to the ocean floor to form layers of new sediment, tiny magnetic grains within the particles align themselves with the magnetic lines of the Earth. Once this rock hardens, it becomes a reliable record of the direction the Earth's magnetic field was pointing at the time of the rock's formation. So, if a rock has been spun around by a dramatic geological event, its magnetic field will have an apparently anomalous orientation that geophysicists like those on Maloof's team seek to explain.

 

"We found just such anomalies in the Svalbard sediments," Maloof said. "We made every effort to find another reason for the anomalies, such as a rapid rotation of the individual crustal plate the islands rest upon, but none of the alternatives makes as much sense as a true polar wander event when taken in the context of geochemical and sea level data from the same rocks."

 

The findings, he said, could possibly explain odd changes in ocean chemistry that occurred about 800 million years ago. Other similar changes in the ocean have cropped up in ancient times, Maloof said, but at these other times scientists know that an ice age was to blame.

 

"Scientists have found no evidence for an ice age occurring 800 million years ago, and the change in the ocean at this juncture remains one of the great mysteries in the ancient history of our planet," he said. "But if all the continents were suddenly flipped around and their rivers began carrying water and nutrients into the tropics instead of the Arctic, for example, it could produce the mysterious geochemical changes science has been trying to explain."

 

Because the team obtained all its data from the islands of Svalbard, Maloof said their next priority would be to seek corroborating evidence within sediments of similar age from elsewhere on the planet. This is difficult, Maloof said, because most 800-million-year-old rocks have long since disappeared. Because the Earth's crustal plates slide under one another over time, they take most of geological history back into the planet's deep interior. However, Maloof said, a site his team has located in Australia looks promising.

 

"We cannot be certain of these findings until we find similar patterns in rock chemistry and magnetics on other continents," Maloof said. "Rocks of the same age are preserved in the Australian interior, so we'll be visiting the site over the next two years to look for additional evidence. If we find some, we'll be far more confident about this theory's validity."

 

Maloof said that true polar wander was most likely to occur when the Earth's landmasses were fused together to form a single supercontinent, something that has happened at least twice in the distant past. But he said we should not worry about the planet going through a major shift again any time soon.

 

"If a true polar wander event has occurred in our planet's history, it's likely been when the continents formed a single mass on one side of the Earth," he said. "We don't expect there to be another event in the foreseeable future, though. The Earth's surface is pretty well balanced today."

 

Maloof's research was sponsored in part by the National Science Foundation.

 

Source: Princeton University

[cwes99_03]

Hey C1ay, can you see if you can find whatever was actually published on Aug 25.

I see problems with this. I haven't finished reading but i thought sediments on the ocean floor with different orientations were likely to be caused by shifts in the magnetic poles. It would be worth mentioning in such an article whether or not this was possible or even likely and it is not mentioned at all.

[cwes99_03]

Additionally, wouldn't polar shift and techtonic activity have to work together to form the current earth land mass and tilt? Or is that what they are saying?

[C1ay]

Hey C1ay, can you see if you can find whatever was actually published on Aug 25.

The abstract is available here. The full text article requires a subscription or a one time purchase of $25....

[cwes99_03]

From the abstract.

We explore four possible explanations for these coincidental changes: rapid plate tectonic rotation during depositional hiatus, magnetic excursions, nongeocentric axial-dipole fields, and true polar wander. We conclude that the observations are explained most readily by rapid shifts in paleogeography associated with a pair of true polar wander events.

 

Looks like they considered a bunch, so I guess I'll have to do a bit of study on this to see if they made accurate conclusions.

[HydrogenBond]

One of the practical problems is that all the continents were part of a single land mass at one time bringing all these volcanoes close enough to balance each other out. Doesn't it make more sense that the single original land mass was the cause of the wobble?

 

The question should be, why did the original land form at one location on the earth instead of randomly everywhere due to volcanoes and such? The most logical answer is connected to the earth stealing material from the moon due to a geosynchronistic orbit. Compare the diameter of the moon with that of the original land mass. Also, the moon points the same face to the earth, stuck in this ancient alignment.

 

Picture this scenario. Both the earth and moon were much hotter and therefore fulffier billions years ago. This means that the crust was far more fluid and the atmosphere much heavier with materials, including water. This made the surface fully susceptable to tidal influences. The resultant geosynchronistic alignment and the earth's higher gravity caused the earth steal materials from the moon, collectiving in the tidal flow. This caused the earth to begin to wobble on its axis spreading out the material into a wider land mass.

 

An alternate explanation is still a geosynchronistic moon orbit but with radiational heating keeping one side of the earth hotter and more plastic longer. This was the easiest zone for mantle stresses to be released causing the land to collect there, until the earth began to wobble. I personally like a combo of the two, with the hot convection fighting the cooling of the earth.

[Bagpi]

Planet earth may have tilted!!...Relative to what??

 

bagpi

[Kuba]

You hit the mark on that one. It tilted relative to what? The Sun?

Couldn't it be possible that the earth's magnetic field simply shifted? Rather than the earth shifting while the magnetic field remaining static? Just a thought.:D

[Bagpi]

As far as my limited imagination can see, the only thing a tilt could be relative to would be the Sun. The rest of the universe would'nt give a monkeys. Without the Sun in the equation and the present tilt giving us the seasons we currently enjoy, how would you guage if there was a tilt. North South East West, seems to me to be a man made observation. Approaching earth for the first time from deep space, the Earth's alignment would depend on your ships alignment with regard to the rest of the universe.

 

bagpi

[cwes99_03]

Titled with respect to its orbit around the sun. You guys need to brush up on your astronomy and geometry a bit.

 

The earth revolves around the sun in a certain plane of inclination compared to the suns rotation on it's axis. Most of the planets revolve around the sun in the same plane. However each planet rotates on it's own axis which may be at some angle to this plane.

 

The angle the earth has compared to this plane is like 22 degrees or something like that. Thus is the cause of the seasons.

 

HBond, as far as the land mass Pangea goes. Having the land mass concentrated at one point near the equator would actually cause a wobble, not otherwise. Volcanoes could also have been under water on the other side of the world when and if there was a Pangea.

[Kuba]

Titled with respect to its orbit around the sun. You guys need to brush up on your astronomy and geometry a bit.

 

The earth revolves around the sun in a certain plain of inclination compared to the suns rotation on it's axis. Most of the planets revolve around the sun in the same plane. However each planet rotates on it's own axis which may be at some angle to this plane.

 

The angle the earth has compared to this plane is like 22 degrees or something like that. Thus is the cause of the seasons.

 

HBond, as far as the land mass Pangea goes. Having the land mass concentrated at one point near the equator would actually cause a wobble, not otherwise. Volcanoes could also have been under water on the other side of the world when and if there was a Pangea.

 

Did you look at what the study found? Because all they say is that there is evidence that earth's magnetic field was different in the past. They hypothesis that the earth was tilted in relation to this altered magnetic field but that is not necessarily the case. The magnetic field COULD have changed without the earth tilting.

[Turtle]

Picture this scenario. Both the earth and moon were much hotter and therefore fulffier billions years ago.

 

Did you mean "fluffier"? Your fluff characterizes the entire exchange of posts after C1ay posted the original article. There is never a cogent answer to an insipid question.

[cwes99_03]

Did you look at what the study found? Because all they say is that there is evidence that earth's magnetic field was different in the past. They hypothesis that the earth was tilted in relation to this altered magnetic field but that is not necessarily the case. The magnetic field COULD have changed without the earth tilting.

 

Thus is what I said way back at the beginning to the discussion of this article. Please read before posting.

[cwes99_03]

Did you mean "fluffier"? Your fluff characterizes the entire exchange of posts after C1ay posted the original article. There is never a cogent answer to an insipid question.

 

Wow, Turtle. Reminds me of the recent bad rep you gave me. Are you saying that all the discussion of this article is fluff? Have you actually read some of my posts? Perhaps you need review your "cogent" statment above and perhaps how "insipid" it was to the discussion of this article.

[InfiniteNow]

Wow, Turtle. Reminds me of the recent bad rep you gave me. Are you saying that all the discussion of this article is fluff? Have you actually read some of my posts? Perhaps you need review your "cogent" statment above and perhaps how "insipid" it was to the discussion of this article.

If I may make a suggestion, this is probably not the best approach toward earning more positive rep...

 

 

As to the article, it's clearly articulated that these are not conclusions, but are instead conjectures and proposals. They will now begin seeking corroborating information in an attempt to further support or disprove their stated hypothesis. I, for one, remain interested in what other things may be learned in these explorations.

[Turtle]

Wow, Turtle. Are you saying that all the discussion of this article is fluff?

Have you actually read some of my posts?

Perhaps you need review your "cogent" statment above and perhaps how "insipid" it was to the discussion of this article.

Yes.

I likely have read all your posts here CW, but I had to choose just one for a brother's attention.

Review complete; everything is copacetic.:confused:

[HydrogenBond]

By fluff I mean the earth was less dense at one time and the crust was much more fluid. Picture if the modern earth began to really heat up from the inside out. The oceans would boil, the land would turn molten, all the pressurized stuff in the mantle would pour outwards. The result would make the earth bigger and fluffier and much less dense.

 

If the hot moon was nearby, and had a geosynchronstic orbit, one zone of the earth would have maximum internal and external heating. It would be the last area for water to condense and be the last area where the mantle is sealed against earth contraction pressure releasing material to the surface. The result was pangea.