S.America and Africa's rate of spreading

Does anyone have an estimate of the rate at which they are spreading and how did you estimate it? Tx

Try this link: At a more detailed level, plus it mentions GPS measurements: --Percy

ah, tx a lot, that was very helpful and interesting.

May I ask why no young earthers want to point out what is wrong with the article referenced in post 2?

Hi Ultima,The Mid-Atlantic Ridge rises above sea level in Iceland and basically splits the island in two parts, each side being on one of the tectonic plates. Before GPS, scientists set up mirrors on tripods on both sides of the ridge. They then fired a red laser at one mirror and adjusted the mirror so the beam was reflected in the next mirror and so on. They measured the distance and angles of the beam as reflected in each mirror. As the two sides of the ridge spread, the angles and distances of each leg of the beam changed. They were then able to calculate the direction and velocity of sea floor spreading without getting their feet wet.I don't have a link, because Al Gore hadn't invented the Web yet. (:raig

"May I ask why no young earthers want to point out what is wrong with the article referenced in post 2? "
--Well despite subsequent explanation on the difference between the half-spreading and full-spreading(or plate separation/divergence rate) the assertion that "These plates move at speeds of about 1 to 15 cm per year" isn't right. While probably an unintentional inconsistency, the 150 mm/yr rate is the fastest separation rate observed in some loci at the Nazca/Pacific accretion boundary. Probably not what you were shooting for though, Nosyned. Firstly, I disagree with the quote given in the paper by Stuart Nevins (1976), "the idea that sea-floor plates form slowly and continuously at a rate of a few centimeters each year as the ocean crust is being rift apart, is not supported by geologic data". I think it is if all the data is interpreted within the uniformitarian presupposition.The section, 'spreading Rates from K-Ar Biochronology' is flawed with its application to that which would be expected in a catastrophist scenario. It is asserted that:

quote:

---

If sea-floor spreading has occured, then the biostratigraphic age of the sediments immediately overlying the oceanic crust should increase with increasing distance from spreading ridge axes. If on the other hand the ocean basins were created raidly and 'all at once,' we would not expect any relationship between distance from the ridge axis and biostratigraphic age.

---

This conclusion is flawed because the flux of terrigenous sedimentary deposition over ocean basins would have to have been much higher than today, possibly proportional to the rate of sea-floor spreading(though probably not in a simple linear way). While the modern ocean floor in the runaway subduction scenario was created very quickly by any standard, it didn't just 'appear'.Also asserted in the essay:

quote:

---

It would be strange, then, if direct observation revealed motion in the 'wrong' directions, or no motion at all, or rates of motion very much faster than those derived from radiometric dating.

---

--The author seems to still have the uniformitarian(that processes occuring today have always been occuring and are responsible for fashioning the earth) mind-set when considering what would be expected in a young seafloor. Catastrophic plate tectonics would have just as much of a problem explaining motion in the 'wrong' direction than would uniformitarian geodynamics. Also, it is obvious that if radioisotopic decay were accelerated, the rate of motion would be interpreted as being much faster. Also, the curve in the acceleration/deceleration radioisotopic decay rate will would also influence any catastrophist interpretation of past spreading rates.Contrary to the authors conclusion that "these observations constitute a robust falsification of 'catastrophicst' tectonic[s]" I don't see this very well substantiated in the essay. The only thing in the essay which, in my opinion, may hint in favour of uniformitarian tectonics is that from astronomical influence of geomagnetic data, though I have not done research on that possibility.Lastly, the final statements are falliceous:

quote:

---

To argue, as young-earthers and some other catastrophists do, that the ocean basins were actually created in a few months and that current spreading rates "just happen by chance to be a near perfect match within the rates derived from the...geologic time scale requires complete abandonment of Occam's razor" (Wise, 1998).

---

Even in the catastrophists view, the current rates of sea-floor spreading and past rates may be related. I think that it is probably due to the correlation between the rate of radioisotopic decay and spreading velocity. This of course probably isn't the only reason for this relationship.Just a few comments.[This message has been edited by TrueCreation, 09-18-2003][This message has been edited by TrueCreation, 09-18-2003]

Well that response fails to deal with the correlation with radiometric dating. It fails to deal with the use of the Milankovitch cycles tp establish dates.The criticism of the statement "It would be strange, then, if direct observation revealed motion in the 'wrong' directions, or no motion at all, or rates of motion very much faster than those derived from radiometric dating." takes it out of contextThe full quote is

quote:

---

If the radiometric and astronomical data are accurate, then plate motions have been remarkably uniform for milions of years. It would be strange, then, if direct observation revealed motion in the 'wrong' directions, or no motion at all, or rates of motion very much faster than those derived from radiometric dating.

---

In short it is not based on a uniformitarian ASSUMPTION but on the evidence that the rate has NOT changed much for a significant period of time - even by geological standards. That the currently measured rates are in close agreement, then, is confirming evidence that the data - and the inferred rates are correct. There is certainly no suggestion that the "wrong" direction would support catastrophism - and to criticise the statement on those grounds is a misrepresentation.
(I would add that those who favour a catastrophist view would be much happier with a significant mismatch in the inferred rate - and even a problem with the direction would likely be welcomed as discrediting the evidence contradicting their view.)The disagreement with the biochronology appears to be pure handwaving - it fails to offer any explanation of why there should be an identifiable biochronology at all. Let alone why it should agree with he expected results.As for the last sentence the point is not that there is a relationship between the rates - the problem is that the past rates inferred from three very different methods all agree with each other and with the current rates. Even with the highly dubious idea of accelerated radioactive decay to try to explain the radiometric data (dubious because there is no plausible mechanism which would raise decay rates - and certainly not one that would proportionately raise all the decay rates used in radiometric dating) it is still a priori unlikely that the spreading rate would rise in direct proportion - why would it ? And that would leave two other measurements giving matching results unexplained. At present massive coincidence is the only explanation available.In the face of this CPT cannot be considered a live possibility as a scientific proposal. It faces serious problems which will likely prove insurmountable.

"Well that response fails to deal with the correlation with radiometric dating. It fails to deal with the use of the Milankovitch cycles tp establish dates."
--My comment on the latter is in my last post if anyone wants to read it. As well as with the radioisotopic dating correlation. There is no reason for me to reitterate but my response to these statements should help:"The criticism of the statement "It would be strange, then, if direct observation revealed motion in the 'wrong' directions, or no motion at all, or rates of motion very much faster than those derived from radiometric dating." takes it out of contextThe full quote is[Snip]In short it is not based on a uniformitarian ASSUMPTION but on the evidence that the rate has NOT changed much for a significant period of time - even by geological standards."
--Thank you for describing an application of the uniformitarian principle.."That the currently measured rates are in close agreement, then, is confirming evidence that the data - and the inferred rates are correct."
--If ultimately radioisotopic decay was constant during the formation of seafloor. As a side note, science is not about correctness, but can only establish degrees of plausibility."There is certainly no suggestion that the "wrong" direction would support catastrophism - and to criticise the statement on those grounds is a misrepresentation."
--This was not my ground for criticism, but was merely a note. What I did criticise is his uniformitarian presuppostion."The disagreement with the biochronology appears to be pure handwaving - it fails to offer any explanation of why there should be an identifiable biochronology at all. Let alone why it should agree with he expected results."
--This wasn't hand waving. I pointed out that the ocean floor didn't just 'appear' as the article at at least one point seemed to suppose, but was formed systematically (despite the catastrophic rates implied). Given this, seafloor more distal to the ridge axis would therefor be older. Also, as is hypothesised during catastrophic plate tectonics, anomalously high oceanic flux's of terrigenous sediment would also be implied. There is, therefore, no serious difficulty that I can see with envisioning that sediments directly superposing ocean floor would be about the same age."As for the last sentence the point is not that there is a relationship between the rates..."
--Well this point was emphasised in the essay and I thought it worth responding to."...the problem is that the past rates inferred from three very different methods all agree with each other and with the current rates."
--The only thing I can see that would be detrimental to that hypothesised for the formation of the oceanic lithosphere in CPT is the astronomical patterns in the record. But again, I havent researched this and don't intend on doing a rigorous one right now. If you, however, would like to privide for the board this data, that may help your case."Even with the highly dubious idea of accelerated radioactive decay to try to explain the radiometric data (dubious because there is no plausible mechanism which would raise decay rates - and certainly not one that would proportionately raise all the decay rates used in radiometric dating) it is still a priori unlikely that the spreading rate would rise in direct proportion - why would it ?"
--radiogenic heat. Hence the term 'thermal' runaway of subduction."In the face of this CPT cannot be considered a live possibility as a scientific proposal. It faces serious problems which will likely prove insurmountable. "
--CPT has inconsistencies, therefore it is not scientifically possible, or even scientific... sure Paul, you keep thinking that.[This message has been edited by TrueCreation, 09-19-2003]

I reread your post and there was no clear answer to either the radiometric data nor the Milankovitch cycles. From your present post it seems that you simply refuse to accept this data.And you seem to be using the usual dodge of calling conclusions presuppositions. There was no assumption that the spreading rates were uniform - that was inferred from the data and confirmed by the modern day observations. How difficult is that to understand ?And yes your response to the biochronology IS handwaving since it presents no explanation of the biochronology at all. It merely asserts that since there are SMALL age differences in the age of the sea floor that somehow this will produce the results we see. But there is no explanation of how. Simply assuming *a* timescale does not mean that the results will be identical to those expected under the conventional timescale - not when there are differences of what - seven orders of magnitude ?As for your attempt to deal with the problem that your scenario requires massive coincidence you appeal simply to the heat produced by radioactive decay. Now I am well aware of the fact that accelerated decay should produce large amounts of heat - but that fact does NOT mean that the spreading rate should increase proportionately to the decay rate. There is no reason to assume that the relationship should be so simple. So no you have not answered the point at all. You have simply assumed the very coincidence you were claiming did not exist.I hope that this pattern of assertion without explanation is not to be found in your "scientific" work.

"I reread your post and there was no clear answer to either the radiometric data nor the Milankovitch cycles. From your present post it seems that you simply refuse to accept this data."
--No really? Did I not say that I haven't done any research on the Milankovitch cycles??"And you seem to be using the usual dodge of calling conclusions presuppositions. There was no assumption that the spreading rates were uniform - that was inferred from the data and confirmed by the modern day observations. How difficult is that to understand ?"
--I dunno, this is something I understood I can't even remember how long ago, so it must be pretty easy... On the other hand, how difficult is it to understand that the uniformitarian principle is presupposed? I didn't say that spreading rates are assumed to be essentially constant, I was commenting on the rate of radioisotopic decay."And yes your response to the biochronology IS handwaving since it presents no explanation of the biochronology at all. It merely asserts that since there are SMALL age differences in the age of the sea floor that somehow this will produce the results we see. But there is no explanation of how."
--It will give these results because the influx of terrigenous sediments in the oceans are also high. The small age difference will not be small if "age" is derived from radioisotopic analysis because decay rate is higher as well.."As for your attempt to deal with the problem that your scenario requires massive coincidence you appeal simply to the heat produced by radioactive decay. Now I am well aware of the fact that accelerated decay should produce large amounts of heat - but that fact does NOT mean that the spreading rate should increase proportionately to the decay rate."
--They didn't, spreading rate has varied a good percentage since the breakup of pangea. Cretaceous seafloor spreading was significantly faster than now, likewise for 20-30 "Mya" seafloor. I am not saying that spreading rate and isotopic decay are proportional by some simple linear relation. I think this is a good suggestion for further research. But unlike you and mainstream science, there aren't many people doing research and theres quite a bit to be done."I hope that this pattern of assertion without explanation is not to be found in your "scientific" work."
--It is a scientific suggestion. Its not like I am saying that this is 'the' answer.

So you think that radioacitive decay rates are just "assumed" to be constant? Is that it?What would the observable consequences be if they were not constant? These consequences can be, and must be quantified. Please supply a reference that does this. Thanks.

I don't count "I haven't done research" as an adequate answer. Since you dismiss the conclusion of the paper without even considering a major line of evidence you need more than that.And no constancy of radioactive decay rates is NOT simply an assumption. The fact is that the relevant decay rates are very hard to change and there is no indication that any known effect could significantly alter any one of them under conditions that could plausibly apply. Moreover to affect ALL the decay rates that are relevant to radiometric dating to the same degree - as your scenario requires - is so far as we know impossible barring miracles. And if I remember correclty creationist research on the Oklo natural reactor limits the degree of accelerated decay possible to little over one order of magnitude.And you're STILL handwaving over the biochronological dating.And finally your model DOES need radiometric decay to be proportional to spreading rate to explain the match between the rates inferred from radiometric dates with the current spreading rates.It seems your apprroach is simply to shout "catastrophe" and assume that the results will match what is actually observed. That is not scientific - it is the wishful thinking of (bad) religious apologetics.And the reason why mainstream scientists are not looking at your ideas is obvious. They are just too implausible to be worth consideration.

quote:

---

Paul: "In the face of this CPT cannot be considered a live possibility as a scientific proposal. It faces serious problems which will likely prove insurmountable. "

​

--CPT has inconsistencies, therefore it is not scientifically possible, or even scientific... sure Paul, you keep thinking that.

---

Inconsistencies?!! You seem to have a gift for the understatement, TC. CPT has several glaring fatal flaws, not the least of which is that there is no diagnostic evidence for it. And you have not addressed a single one of them except for the fanciful notion that radioactive decay somehow accelerated and then decelerated by many orders of magnitude at some time in the past and left no evidence of it ever happening. It seems that you have already abandoned your magnetic stripes argument (wisely, I might add), so what have you got left?It seems that now your main contention is that uniformitarianism is the ultimate culprit here. If this is the case, you need to collect evidence to support it. First, I would expect that you show your understanding of the modern concept of uniformitarianism (actualism, I believe someone called it) by giving us a definition. Then you need to show where uniformitarianism is erroneous. After that you should give us some guiding principles, replacing uniformitarianism in the interpretation of the data. Please give us some actual evidence, and lose the vague generalities belittling the assumption of uniform processes.

"So you think that radioacitive decay rates are just "assumed" to be constant? Is that it?"
--I wasn't inputing any sarcasm or anything like that. But yes that was my point, the assumption of uniformitarianism."What would the observable consequences be if they were not constant? These consequences can be, and must be quantified. Please supply a reference that does this. Thanks."
--Very good question. One that I hope I will have thoroughly answed in the next couple decades. The effects of radiogenic heat should be quantified. I already know most of the benefits and plenty of the problems associated with radiogenic heat so these do not have to be substantiated before me. These problems are being worked out.I cannot apply you a sufficient reference because the research has yet to be carried out.

"I don't count "I haven't done research" as an adequate answer."
--Neither do I. Did I say it was an answer? Or even that I had one?"And no constancy of radioactive decay rates is NOT simply an assumption."
--That it is assumed is my point."The fact is that the relevant decay rates are very hard to change and there is no indication that any known effect could significantly alter any one of them under conditions that could plausibly apply. Moreover to affect ALL the decay rates that are relevant to radiometric dating to the same degree - as your scenario requires - is so far as we know impossible barring miracles."
--I admit that if accelerated decay has occured, it was caused supernaturally. Of course if it wasn't, the Flood could possibly be explained completely by naturalistic processes."And if I remember correclty creationist research on the Oklo natural reactor limits the degree of accelerated decay possible to little over one order of magnitude."
--So, do you remember correctly?"And you're STILL handwaving over the biochronological dating."
--Why is my explanation inadequate?"And finally your model DOES need radiometric decay to be proportional to spreading rate to explain the match between the rates inferred from radiometric dates with the current spreading rates."
--As far as I know, yup. Then again, this is only something I have been musing on for a couple days... It would therefore be ridiculous for me to attach any more credibility to my suggestion beyond what it is--a suggestion."It seems your apprroach is simply to shout "catastrophe" and assume that the results will match what is actually observed."
--lol.. um, no."And the reason why mainstream scientists are not looking at your ideas is obvious. They are just too implausible to be worth consideration."
--More accurately, they are not looking at these ideas because they already have their answers. Besides, when you have millions of years, who cares?