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Thursday, October 30, 2014

Those Plates, They Are A-Movin’

Posted by jlwile on April 30, 2012

This map of a portion of the earth shows the motion of specific locations relative to a fixed point. The arrows indicate the velocity of each location, and the blue lines are the outlines of what are thought to be the plates that are producing this motion. (Click for credit)


In the theory of plate tectonics, the earth’s surface is broken into several distinct plates which move about, carrying the continents with them. As a result, a fixed location on the planet is not really stationary. It is actually moving along the earth! We don’t notice the motion, of course, because it is happening very slowly. However, according to the theory, it is always happening. If scientists make certain assumptions about how this motion occurred in the past, they can conclude that at one time, all the continents on earth were grouped together in a supercontinent called Pangaea. Over time, the motion of the plates then separated the continents into the positions we see today.

If you assume that the plate motions we think are happening today are representative of how fast the plates have always moved, you find that it would take hundreds of millions of years for the continents to have moved from Pangaea to where they are today. However, many young-earth creationists think that plate motions were much faster during the worldwide Flood, and some have produced detailed computer models that attempt to explain how the Flood happened in the context of this catastrophic plate tectonics. Other young-earth creationists are skeptical about plate tectonics, claiming that there isn’t a lot of evidence to support it.

I tend to disagree with the young-earth creationists who are skeptical about plate tectonics. While I am definitely not a geologist or geophysicist, I do think there is a lot of indirect evidence to indicate that the plates are real and that they are really moving. Interestingly enough, I recently ran across an article by Dr. John Baumgardner that, in my mind, really clinches the case for the reality of plate tectonics.1 Not only that, the data used in the article are just plain cool!

It turns out that the Global Positioning System (GPS) has been monitoring over 2,000 stationary receivers that have been placed all over the earth. The GPS confirms that these receivers are moving at surprisingly constant velocities, despite the fact that they are fixed to the ground. The map shown at the top of the post, for example, displays several of the receivers and the directions in which the GPS confirms that they are moving. If you go to the Jet Propulsion Lab (JPL) website that archives these data, you can look at any part of the world and see the receivers that are there and how they are moving. If you do that, you will find that they are moving the way you would expect them to move in the context of plate tectonics.

What’s really fascinating to me about these data is how detailed they are. For example, some of the fastest motion detected by the GPS is around Australia and New Zealand. Let’s look at the GPS data for a receiver that is sitting on the Cook Islands, which are in the Western Pacific, east of Australia:

Changes in latitude, longitude, and elevation for the Cook Islands station over the past ten years. (NASA/JPL image)


The black dots are the data, and the red lines are simply meant to guide your eyes along the data. Note that the graphs span a bit more than ten years. In that time, the receiver has moved about 36 centimeters in latitude and about 60 centimeters in longitude. Its elevation, however, hasn’t changed significantly. Now look at the data points themselves. Notice that for both longitude and latitude, most of the points fall along an almost perfectly straight line. There are a few deviations here and there, but the straight lines are unmistakable. Physics tells us that the slope of a position versus time curve tells you the speed. Since a straight line has a constant slope, the straight lines in these graphs tell us that the speed at which the Cook Islands are moving has stayed remarkably constant over the past ten years.

I just think it is nothing short of awesome that we have these data!

REFERENCE

1. John Baumgardner, “Is Plate Tectonics Occurring Today?”, Journal of Creation 26(1):101-105, 2012
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Comments

20 Responses to “Those Plates, They Are A-Movin’”
  1. Seth says:

    I agree, it’s incredible that we can come up with such nice linear data (if all data was like this it would make science a whole lot easier).

    I absolutely love science, I’m actually majoring in Physics. I’m always looking for good resources to read, but it seems like I’m always outdated on everything. How, with your busy schedule, do you keep up with science, where do you find all your resources?

  2. jlwile says:

    Seth, you are certainly right that if all data were like these, science would be a whole lot easier! I keep up with science by making reading a priority. I read PLoS ONE, Science, Science News, and Journal of Creation regularly, and I also surf the science blogs for news not covered in those journals. I used to read Chemical and Engineering News as well, but I don’t do that regularly anymore.

  3. Hi Dr. Jay, Recently I’ve heard some Christians talking about ley lines and magnetic vortices (ie Bermuda Triangle, Devil’s graveyard in Alaska, etc I think there are said to be 12?) and the possibility of their spiritual significance. Just wondering what your take is on all that. Are the scientific properties of these places different than other places on earth?
    Thanks, Sandy

  4. jlwile says:

    Sandy, I haven’t looked into the specifics of places like the Bermuda Triangle and the Devil’s graveyard, but I follow the scientific literature pretty closely and haven’t read anything to indicate that such places have different properties than other places on earth.

  5. Seth says:

    Thanks for the reply, I’ll add those to my Google reader account :)

    Sidenote: I discovered your blog about two months ago and I’ve always found your style very appealing, you always make the science interesting and down to earth. Keep it up!

  6. jlwile says:

    Thanks so much, Seth!

  7. Scott Warner says:

    Dr. Wile, a related question — would you comment on the Hydroplate Theory as proposed by Dr. Walt Brown. Thanks.

  8. jlwile says:

    Scott, I am not very impressed with Dr. Brown’s model. It is long on ideas and short on details. Also, it seems to me he has some basic geophysical problems. For example, in order for his model to work prior to the Flood, he would need the earth’s crust to be impervious to water, which is certainly not what we see today. In addition, the crust could not have any serious hills (much less mountains), as they would cause a buckling stress that would create the kind of microfractures that would let the water out long before it should be let out. Also, the physics of the water release doesn’t seem to work. The water is under so much pressure that it would be released at a velocity above escape velocity, which means much of the water would simply fly out into space, never coming back to make the Flood.

    By comparison, the catastrophic plate tectonics model is significantly more worked out, with a detailed computer model that at least incorporates some good physics. Overall, I think it is the best model available right now. That doesn’t mean it is the right model, of course.

  9. D. Perrine says:

    Concerning the graphs, is it possible that the motion is not linear? We only have a small time scale to deal with and this could be the approximation of a tangent line situation where the graph is so enlarged that the overall curve looks straight.
    I was just curious because I remembered your old post (http://blog.drwile.com/?p=9).

    Always a pleasure to read.

  10. jlwile says:

    Excellent point, D. Perrine! It could be that the speed is varying so slowly that in a ten-year period, it only appears to be constant. In addition, it could be that the speed varies over different periods of time. It might be constant over a generation or so and then change dramatically, depending on the conditions of the mantle.

  11. Kevin N says:

    The GPS data is just one of many convincing evidences that plate tectonics is occurring today, and that it has been active throughout geologic history, whether that history be measured in billions or thousands of years.

    Conventional (i.e. old-Earth) geologists do not say that the rate of sea-floor spreading has been constant throughout Earth history. For example, there is evidence that the rate of sea floor spreading in the Cretaceous was up to three times that of today. Going further into the past, heat generation in Earth’s interior in the Archean (early Precambrian) could have been 2-3 times greater than it is today due to greater concentrations of radioactive isotopes of uranium, thorium, and potassium. However, this would not have necessarily meant faster rates of plate tectonics, and many Precambrian experts believe that plate tectonics did not occur in its modern form before three or so billion years ago.

    The problems with young-Earth plate tectonics models are numerous:

    –The greatly increased rate of sea-floor spreading and other volcanic activity would have led to extremely high carbon dioxide concentrations in the atmosphere. Christian geophysicist Glenn Morton calculated that the amount of CO2 produced by volcanism in the flood year would have been sufficient to raise atmospheric CO2 levels to over 58000 ppm. (Morton was once a YEC and even published several articles in the Creation Research Society Quarterly. He had a crisis of faith when he figured out that YEC didn’t work, but by God’s grace retained his faith).

    –Much of the plate tectonic activity would have had to occur in the first 40 days of the flood, with most of the remaining movement occurring in the following months. This means that a considerable portion of the 10-km thick oceanic crust would still have been molten or semi-molten at the end of the flood. Thick bodies of magma do not cool overnight. Semi-molten oceanic crust would not have subducted beneath continental crust in the same way that solid slabs of oceanic crust subduct today (or perhaps would not have subducted at all).

    –Plate tectonics is the driving force behind mountain building, which often involves the folding and faulting of sedimentary rocks. If these sedimentary rocks formed during the flood, they also would have had to completely solidify within a few days or weeks in order to have the brittleness to be faulted or the strength to be folded without turning to massive sediment flows.

    There are more problems for “catastrophic flood geology,” some of which are detailed at the old-Earth Christian site Answers in Creation.

  12. jlwile says:

    Thanks for your comment, Kevin. I agree that there is a lot of evidence for plate tectonics. I also understand why old-earth geologists are desperate to point out one of the very few young-earthers who became an old-earther (Glenn Morton, who has a B.S. in physics), while they ignore the many (more qualified) old-earthers who became young-earthers, like Roger Sigler (M.S. in geology). By God’s grace, Sigler and others like him are able to follow the evidence despite the peer pressure that leads many to ignore the evidence and believe in an old earth.

    Not surprisingly, Morton’s CO2 argument is absurd. What Morton fails to consider is the huge amount of water introduced to the system as a result of the Flood. This water would have acted like a sink, absorbing the CO2 so it would not rise to high levels in the atmosphere. I truly don’t understand how any serious physicist could make such an amateurish mistake!

    I agree that thick bodies of magma do not cool overnight, but they also don’t have the runaway subduction that would have occurred during the Flood. The convectional flow resulting from runaway subduction of the cold ocean-floor slabs would have cooled the mantle temperature at the core-mantle boundary. This would have greatly accelerated heat loss from the adjacent outer core. Indeed, catastrophic plate tectonics is the only model of which I am aware that can actually balance the “energy budget” of the earth for the plate movements that geologists think have happened. I think you need to learn a bit more about the theory before you attempt to critique it!.

    I agree that sediments would have needed to lithify rapidly during the Flood, but that is not a problem. Lithification is not at all slow, given the proper conditions. Instead, the time frame is dependent upon the presence of cement, pressure, and other chemical issues. If the right conditions are met, sediment can be turned rapidly into rock. As someone who follows the data, I understand that there is no problem with rapid lithification under the right conditions. After all, old-earthers once assured us that opals took thousands upon thousands, if not millions, of years to form. Now, of course, we know better. The same is true for lithification.

    Not surprisingly, the article you link at Answers in Creation isn’t any better when it comes to giving a realistic critique of catastrophic plate tectonics. Indeed, it tries to use radiometric dating as evidence against the theory. Anyone who has spent any time at all on this blog knows that radiometric dating is fraught with difficulties – so much so that as a nuclear chemist, I was drug away from it, kicking and screaming! In addition, catastrophic plate tectonics has also made a successful prediction about data that were subsequently discovered (see prediction #4). Thus, far from being problematic, catastrophic plate tectonics is (according to the data) a superior theory compared to old-earth plate tectonics.

    In actuality, the problems with plate tectonics lie mostly on the old-earth side, as described by PhD geologist Dr. Andrew Snelling.

  13. Kevin N says:

    Jay,

    As I expected, you have given a well-reasoned, well-written response. However, I didn’t find any of your arguments to be convincing.

    As I read through Morton’s calculations last night, my impression was that he considerably underestimated the amount of CO2 that would have been produced by volcanism during the flood. His calculations included data for flood basalts—the term “flood basalt” has nothing to do with Noah’s flood—such as the Deccan Traps and Columbia River Basalt, but he does not seem to have included mid-ocean ridge basalts formed by sea floor spreading. In any case, I don’t think that the YEC “the oceans acted as a CO2 sink” argument works. If CO2 was absorbed by the oceans, then it has subsequently gone somewhere. The YEC hypothesis is that it has been removed from the oceans in the form of carbonate sedimentary rocks, such as limestone. But most limestone is composed of fossils, such as clams, brachiopods, bryozoans, and corals, in a matrix of biogenic lime mud. For the YEC explanation to work, the CO2 would have had to go into the ocean, been incorporated into organisms that were somehow growing in murky water during the flood, deposited as limey sediments, and then lithified. If you say this isn’t what happened, then you need to suggest another final sink for all that CO2.

    Perhaps I am misunderstanding something, but Brown’s hydroplate theory involves the addition of a “huge amount of water” to the oceans from the mantle, but the catastrophic plate tectonics model does not. Snelling’s description of catastrophic plate tectonics that you referenced states “this hot mantle material vaporizes huge volumes of ocean water with which it comes into contact to produce a linear curtain of supersonic steam jets.” The large quantity of CO2 would have gone into existing ocean water, not into introduced mantle water.

    If oceanic crust had crystallized rapidly, as catastrophic plate tectonics requires, then the structure of oceanic crust would be radically different. The uppermost part of oceanic crust is characterized by pillow basalt, which formed in contact with seawater. Beneath this pillow basalt is a series of densely packed dikes, and deeper still, the oceanic crust is composed of course-grained gabbro. The dikes are not thick, as they should be if sea-floor spreading was occurring at a meter per second. Neither of these deeper zones show any indication of rapid cooling. The muddled geomagnetic signature of the deeper rocks is an indication that they took a long time to cool.

    Some sedimentary rocks can lithify on a relatively short time scale, though to cement thousands of feet of sediment per week in some cases is a stretch. Many cementation processes involve movement of fluids through poorly-connected pores or even migration of ions through solid material, and this isn’t going to happen in just a few days, which is what would be necessary in many cases. This is especially true for rocks where there is ample evidence of multiple cementation episodes or where one cement, such as calcite, has clearly been replaced over time by another cement, such as silica. Trying to deposit the sediments, bury them, cement them, re-cement them, and then fold and fault them within just a few weeks is typical of YEC geology: too many events, too little time.

    Plate tectonics is happening, but it has never progressed at the catastrophic rates proposed in the current YEC model.

    Grace and Peace

  14. jlwile says:

    Thanks for your thoughtful reply, Kevin. I will still have to disagree with you, however. First, Morton may, indeed, have underestimated the amount of CO2 released by catastrophic plate tectonics. He also may have overestimated it. That’s the problem with estimations. We really don’t know. The main problem, however, is that he definitely underestimated the sink, and therefore his increase in atmospheric carbon dioxide is certainly wrong.

    When I wrote about the “huge amount of water introduced to the system,” I wasn’t writing about new water. I was writing about the steam jets you correctly described in your reply. Remember, CO2 enters the oceans by interactions between the atmosphere and the surface of the ocean. This is very inefficient, reducing the amount of CO2 that can (and does) dissolve into the ocean. When the water is vaporized to form jets of steam, it then falls back to the ocean through the atmosphere. So all this CO2-poor water is being introduced directly into the atmospheric system. This would promote a huge amount of dissolution of CO2 into the water. Until you properly take into account this huge, fast CO2 sink, you can’t come close to properly estimating the carbon dioxide in the atmosphere.

    I agree that the dissolved carbon dioxide had to eventually go somewhere, and microorganisms are the most likely place that it went. In fact, the muddy Flood waters would have been ideal for coccolithophorids, which would bloom in the nutritious, sediment-laden water. Because of their short lifetime, an enormous amount of carbon dioxide would be converted into calcium carbonate in a short amount of time. Eventually, much of it would then be deposited in sediments.

    I am not sure that the structure of the oceanic crust would be different under plate tectonics. You are assuming what rapidly-cooled oceanic crust would look like had it cooled rapidly. In fact, there would have been a lot of things going on during catastrophic plate tectonics, and until you take into account all these factors, it is hard to believe that you can accurately predict what the oceanic crust should look like. However, you can accurately predict what the ocean floor should look like if plate tectonics was always slow and gradual, and it most certainly doesn’t look like that at all. Drilling into the seafloor, for example, reveals rapid and erratic changes in the polarity of the earth’s magnetic field. This is quite opposite of what you would expect from slow-and-gradual plate tectonics, and it is at least consistent with catastrophic plate tectonics. In addition, slow-and-gradual plate tectonics should deform and thrust-fault the seafloor. However, looking at the East Aleutian and Peru-Chile Trenches, you don’t see any of that. Once again, they are consistent with what you would expect from rapid subduction.

    Actually, lithifying thousands of feet of sediment rapidly is not a stretch at all. The same chemistry that works on thin layers of sediment works on thick layers as well. If the right chemical and physical properties exist, sediments can, indeed, lithify quite rapidly. I agree that SOME cementation processed would not work well in Flood geology, but there are plenty that would work quite well, especially given the excellent mixing that would occur during the Flood. In the end, your comments are very typical of an old-earth geologist commenting on Flood geology – you assume slow and gradual processes and then claim that there is not enough time for these things to happen in the Flood. However, those kinds of processes are not what drive Flood geology. Catastrophic processes drive Flood geology, and our studies of catastrophic geological processes show that there is, indeed, plenty of time for most of the geology we see today to have been formed rapidly in a worldwide Flood.

    Lots of evidence points to the fact that the plates did, indeed, travel quite rapidly at one point in earth’s history. The more we learn about geology, the more clear this becomes.

  15. J.S. says:

    Very interesting discussion here. I would contribute that GPS-derived indications of surficial movements may be consistent with elements of plate tectonic theory such as subduction and mountain building, but are not probative in and of themselves. There are other problems, for example, the fact that the total length of spreading sites is 3x longer than that of subduction sites (“Origin of Mountains (2000, Ollier and Pain).

    In regard to carbonates, Ka┼║mierczak et al (1996), in a widely-cited article, state that “The origin of micritic and peloidal limestones comprising the bulk of many ancient marine carbonate deposits represents a major unsolved problem of carbonate sedimentology.” (http://www.app.pan.pl/article/item/app41-319.html) In a remarkable statement about the singularity of peloidal deposition, they conclude that, “… the entophysalidaceans, pleurocapsaleans, and similar coccoid benthic cyanobacteria living in an uncalcified state in modern seas are waiting for the restoration of excessively alkaline environmental conditions to imprint again their micritic/peloidal signature on widespread areas of the shallow sea floor.”

  16. jlwile says:

    Thanks for your comment, J.S. I agree that marine carbonate deposits can be very problematic for old-earth geologists. I was wondering how you would explain the surficial movements in a non-plate-tectonics way. I have not read Ollier and Pain’s book, but I have read the “plate tectonics wars” in the young-earth creationist literature, and I do think the plate-tectonics camp makes a much stronger argument. When I saw these GPS data, they seemed to clinch it for me. However, I would be open to hearing an alternate explanation. Particularly, I would like to know why the observed movements seem correlated so well to the plates, even though the plate boundaries were not determined using these data.

  17. J.S. says:

    Doing research to answer your question brought to my attention the existence of an e-book called “The Flood Science Review,” which contains back-and-forth discussion between proponents of different positions on the flood, and is made available by a group called “In Jesus’ Name Productions,” which is hoping to make a movie about the flood:

    From the web page:

    The Flood Science Review eBook is a 1,645 page PDF document that has been linked throughout to ease navigation. It contains every exchange between our Authors and Panelists and between our Authors and each other. We believe this eBook gives a very accurate view into the strengths and weaknesses of our current Flood models. Additionally, it helps set direction for where the Creation Community may need to go to reach the goal of a truly mature and defensible Flood model.

    Obviously, this is a long document, but I suspect that it, plus the information on the web page about participating and non-participating authors (http://www.injesusnameproductions.org/pages/page.asp?page_id=167123), would be about as complete a reference as one could possibly get on the state of flood modelling in the scientific Christian community.

  18. jlwile says:

    Thanks for the link, J.S. It does look like a very comprehensive resource.

  19. J.S. says:

    I realized I didn’t include a link to the Flood Science Review ebook itself–here it is: http://www.injesusnameproductions.org/pages/page.asp?page_id=167120

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