Mainstream plate tectonics model is nowhere near quantitatively correct

I'm not familiar with Anderson's work, but is it really true that he has "his own new theory" of continental drift, as TB claims in the first paragraph of post 1.The Anderson quote is pretty short, so there's little context, but he appears to be commenting on the lack of success in developing a mathematical model for plate tectonics. Is that right, Joe? If so, then this simply seems analogous to weather. We have observational evidence for weather to the point where we can characterize it's behavior in great detail, but it is so complicated that we cannot develop mathematical models that predict weather more than a few days out.I imagine the same difficulties exist for mantle convection currents and plate tectonics. We have tons of data on the motion of continents over time, so much so that you can watch animated movies showing the dance of the continents from Gondawanaland to today, but we have yet to develop a successful mathematical model replicating that behavior over a billion years.--Percy

Tranquility Base writes:

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Come on Joe, Humphreys just drew a Corel Draw sketch to give us some sort of feeling that was in his head. And sure it may be based on that data in a sub-conscious way. He seems to have reverse timed it, shifted the horizontal axis and accelerated the reversals? But he really is just trying to show us what the creationist have in mind empirically. Do you have a diagram on the web somewhere of what the entire time sequence of reversals is from the mainstream POV?

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It appears to me that Humphreys makes these serious mistakes in his diagram:

• Though there have been no reversals in at least the last 7000 years, Humphreys diagram nonetheless includes reversals. Only fluctuations have occurred in the last 7000 years.
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• The flood model requires not the 4 reversals shown on Humphreys diagram, but somewhere in the neighborhood of 1000.
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• He places the fluctuations thousands of years ago to make them coincide to the supposed flood, when in reality the fluctuations have occurred approximately since Christ.
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• He shows the intensity decreasing since the Creationist date for creation, when in reality it has increased.

Humphreys diagram is a fancy of his imagination, is not based upon real data, and bears no resemblance to reality, yet his label says, "Magnetic field intensity at the earth's surface, from creation to now."Humphreys is doing worse than playing fast and loose with the data. This is simple misrepresentation. As a scientist you should deplore such behavior.--PercyPS - Lost that reply button again?

Hi wj!The "Lost that reply button" comment was just a hopefully gentle reminder to Tranquility Base to use the little "Reply" icon that's with the list of icons at the bottom of each message, instead of the big "Post Reply" button that appears at the top and bottom of the entire page. Since he tends not to quote any text, without the "This is a reply to" annotation that use of the "Reply" icon adds it's very hard to tell who he's replying to.In other words, he should take his time composing a reply. Whenever he has available time is fine.--Percy

Andor writes:

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I understand that, with time, as ocean plates become older they get thicker and denser by underplating. So eventually the plate does not float any longer and begin subducting into the mantle. With this, the movement of the plates reverse, until all plates rejoin in one big supercontinent and the cycle restarts once again.

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I'm won't comment about underplating nor about ocean plates becoming denser with time, but sea floor formation and subduction is not thought to operate as you describe here. Sea floor is produced at mid-oceanic ridges at the rate of a few inches/year. Where sea floor meets continent it can be subducted beneath the lighter continent. This is what is happening around the Pacific perimeter. For example, the Pacific plate is subducting beneath the west coast of the US.This subduction process does not take place along the east coast of the US because the continental US is part of the North Atlantic plate, which includes the west Atlantic. Thus, as sea floor is produced at the mid-Atlantic ridge at the rate of several inches/year, the entire sea floor to the west of the ridge plus both American continents are being pushed west.You're probably correct about another supercontinent eventually forming, though. With the Americas being pushed west and with Asia possibly moving east, they may eventually collide.--Percy

Joe, I'm probably asking you to repeat something, but I'd like to know more about subduction that doesn't result from plate collisions. One specific question, is there a contemporary example of this somewhere in the world?Andor, follow Joe on this. He knows much more than me on this topic.--Percy

What does it mean for the polarity of a subduction zone to reverse, and what is the geological evidence for such events. Thanks!--Percy

Joe, Edge,Thanks! Had never heard of this before.About underplating, in general is this a significant contributor to plate thickness? Does deplating (you can tell from the terminology that I'm a professional geologist ) also occur? In fact, does it sometimes occur that the lithosphere wears very thin or wears away completely?Underplating isn't in the site's geology glossary. Can someone provide a laymen's level definition that I could add? And for it's opposite if there is such a term? Thanks!--Percy

Hi Joe,Took a closer look at your picture. Really neat! I didn't realize Australia and Antactica are moving north that rapidly. Also neat is that you have eastern Africa rifting off into the Indian Ocean to become the Somali Plate. It must be moving much slower than Australia. What's the little yellow piece between the African fragment and Antarctica?--Percy