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Arc, In the argument about fast mountain building and episodic growth spurts: 1) You show some problems with the standard model. Great, very interesting! 2) You add some kind of alternative explanation (in the form of cartoons). OK good you're thinking at least! Now just add the maths! 3) You add some evidence -- midocean ridges bulge upwards. Here are the problems: • The evidence does not support your theory because your model is nothing more than cartoons -- you really need those numbers! • One obvious consequence of your model is that there would need to be compressive faults at the mid ocean ridges to accomodate the crustal shortening. There aren't any observed in nature. BOOM your theory is wrong. (truth hurts sometimes) • There is already a perfectly good *quantitative* description of the mid ocean ridge bulge (Parsons and Sclater). This latter point relates to your second argument about the height of transform ridges. Here you: 1) You show that transform ridges bulge upwards and this is not explained by the Parsons and Sclater model. Great, how interesting! 2) You ramble on for a while without making a coherent point. Presumably here you mean to destroy the standard model again and thereby free your path to our hearts and minds. However, just because the Parson and Sclater model does not explain EVERYTHING does not mean that it explains NOTHING. To me, the failure of the Parsons and Sclater model at the these locations reveals that the underlying physics used in that model does not apply in these situations. Parson and Sclater model is a thermal model of topography, and therefore the bulges at tranform faults are not thermal features. Besides, non of this helps you to escape the fact that there are still no compressive faults at the mid-ocean ridges. And that for me is the killer blow to your theory. You could disprove Parsons and Sclater all day long and it wouldn't make the darndest difference.

Welcome back arc, nice to see that after the long break you are still adhering more strongly than ever to your beloved paradigm of planetary sciences! Let's see if this time you can break through the most rigorous barriers we can assemble for you and shatter our perception of reality. One small thing I think you forgot to address. Where are the compressive faults?

The speed of the wave (tsunami) depends strongly on the water depth: shallow water leads to slower wave propagation. The slowing down of the wave as it reaches the shore causes the wavelength to shorten and to conserve energy the amplitude of the wave increases. This is why tsunamis are so high at the shore but barely noticable in the open ocean.

Indeed, welcome back Ophiolite!

True, but this is a much slower process of heat transfer, which explains why the ice does not melt so rapidly. I think we've reached consensus in understanding the mechanism.

I think the idea is that the surface layer is buoyantly stable -- i.e. there is not a "gravitational imperative" for the deep layer to rise to the surface. It is stable because it is less dense than the water below, and it is less dense because it is fresher (less salty). This is despite the fact that it is also colder (which would tend to make it more dense). I don't quite understand the second point. I do not think it "remains the same". In fact I think the whole ocean is constantly circulating and one would have to look at the sources and sinks of the water. I think the question you might be looking for is: what is the source of the cold surface layer in the Southern Ocean? Hi iNow, Yes, that link is essentially the source of the information I previously had summarised (the same research group even). So we are on the same page! I only asked for comments because you posted a lot of information without giving any context. I wanted some discussion context for all that information. Thank you for clarifying your position. Now your previous posts make sense!

Dimensional analysis really is not much to learn. You can *easily* learn it in an afternoon. Calculus on the other hand is something you could be studying for years and years.

Hi studiot, Not exactly. They say there is more rain and snow now which creates a layer of fresh water at the surface. This layer prevents warmer deeper waters from reaching (and melting) the sea ice at the surface. The (salty) warm deep waters were always there -- only now they cannot mix to the surface so effectively. (Disclaimer: I haven't read the original paper: Zhang, 2007)

Care to comment? Also: Antarctic ≠ Arctic

According to the website (http://www.cpom.ucl.ac.uk/csopr/seaice.html) an unusually cold summer in 2013 was the cause of a jump in sea ice production. 'The volume of Arctic sea ice increased by a third after the summer of 2013 as the unusually cool air temperatures prevented the ice from melting.' However, overall, sea ice production is declining over the long-term. 'Although the jump in volume means that the region is unlikely to be ice free this summer, temperatures are likely to rise in the future, and so the events of 2013 will have simply wound the clock back a few years on the long-term pattern of decline.'

Like a black swan? I guess it would have to be. I think in this case you can use a lot of artistic license.

This is not science.

So on what basis does your new "theory" reside other than the hunches that you have based on the cherry picked observations made by your untrained eye?

For me science is about getting to the truth. That does not mean that (the currently favoured) theory is truth. Rather like a map, the map helps us to navigate the complex world and answer specific questions (how do you get from A to B?) but the map itself is not the complex world. Theory is a bit like a map. Sometimes maps can be plain wrong, but usually they're good for something, even though an objectively better (more accurate map) is possible / exists.

Let me see if I understand what you are trying to do correctly. You want to see if your intuitive guesses about the positions of Mars and Venus match up to reality... My recommendation would be to produce a plot. Plot a timeseries of the actual positions of the planets and then on top plot the points that you guessed. Then you will quickly be able to see if your points fall on the line or not. After that you can get a bit heavier on the statistics.

I'm glad to have helped You could probably clean up that "z" trick. But hey -- if it works! -- it works and sometimes that's all that matters. Learning the basics of awk is worthwhile (I notice you're using it in your cleaned up script to print $3). If you ever deal with very large text files learning how to use the arrays (as I demonstrated) will give your code some muscle.

Hi, just some (hopefully helpful) comments about your code, bear in mind I don't have access to your files (too lazy to download them myself) so the suggestions I have will probably need tweaking: It looks like you are using some tricks that you figured out for yourself like the idea of replacing the '.' with a ',' grepping it out and then changing it back again. While these are very clever, they're unnecessarily complicated and would be considered bad "style" because they make the code hard to read and may cause unintended side effects. If longitude is always in the same column there are useful tools such as "awk" (or the vastly improved gawk) that will do a good job for you. I also don't like the way you are looping using an until statement and modify your variable with some quite clunky code inside the loop. The whole thing can be done much more elegantly using a for statement: #! /bin/bash dlist=$(cat ~/astr/dates) echo "initial dlist "$dlist list="" until [[ $dlist == "" ]]; do ## Assigns the next value in $dlist to $date, then removes it from $dlist. date=$(echo $dlist | sed "s/-/z/" | tr " " "\n" | grep z) date=$(echo $date | sed "s/z/-/" | tr ">" " ") # The above could probably be made more concise (and readable) using something like: # for date in $(cat ~/astr/dates) ; do echo "date "$date dlist=$(echo $dlist | sed "s/-/z/" | tr " " "\n" | grep -v z) echo "dlist "$dlist ## Greps the table with $date, then isolates and assigns the longitude value(s). longitude=$(cat ~/astr/merc | grep "$date" | sed "s/\./\,/" | tr " " "\n" | grep [,] | tr "," ".") # There might be an easier way to do this, e.g. (where Y is the column number containing longitude): # longitude=$(cat ~/astr/merc | grep "$date" | awk '{print $Y}') ## Appends $longitude to $list. list=$list" "$longitude echo $list # Is this "list" of longitudes getting longer and longer and you're printing it out every iteration? Why? Lots of duplication! done ## Indicate completion of the until loop. echo "List completed." It looks to me like the whole thing can be done far more quickly and concisely with a single call to awk. #!/bin/bash # Print the date and corresponding longitude for each date in the date file. datefile=~/astr/dates mercfile=~/astr/merc gawk -v datefile=$datefile -v mercfile=$mercfile \ 'FILENAME==datefile { dates[$1]=$1; next} \ FILENAME==mercfile { if (($X) in dates) { \ print dates[$X],$Y}' \ $datefile $mercfile # Where $X is the column number containing the datestring in the mercfile \ # and $Y is the column number containing the longitude in the mercfile. If you want more help maybe you can post a head of the two files you are looking at to give some idea of what they look like. Hope it helps.

Perhaps off tangent slightly but the geocentric approach is also, more generally, a way to do science (cf. the ab initio approach). https://books.google.co.uk/books?id=KB3KsIPa94sC&pg=PA3&lpg=PA3&dq=geocentric+vs+ab+initio&source=bl&ots=2UtcXH4tyP&sig=HPGWYVhMu54nuksT_najuVpBh0c&hl=en&sa=X&ved=0CBkQ6AEwAWoVChMIzvzyhNXpxgIVQdcUCh2lUQ37#v=onepage&q=geocentric%20vs%20ab%20initio&f=false

Yes, you are correct. However, Arwen (and cohort) do make an ellipticity correction to account for this; she just doesn't talk about it on the radio. Probably fair enough given the average level of the audience.

If you allow us to remember the Japanese earthquakes. You were then predicting cycles on timescales of human history (thousands to tens of thousands of years). Now you've changed your mind -- it' million of years. Are we forgetting all that Japanese earthquake stuff now? Aside tip on scientific communication: Arc it is not clear "from that paper". It would be better to say something along the lines: "it is clear that X is true based on the evidence Y (reference to paper)". Anyway, my understanding is that the mantle is constantly supplying melt to produce oceanic crust, but the rate at which it provides melt is fluctuating. It is entirely not clear that the mantle is moving "out and then back in a cycle of several million years" at all, at least not to me! That's your spin on it! Vitally, there is no mention of stopping and starting which you agree your model requires ... Then where are all the compressive faults? (another question repeatedly ignored!) This is ridiculous. Your model is global. How on Earth does it predict local "hotspot" volcanism?

Definitely cool.. To be clear though this paper is about slab detachment. Potentially an important process in rapid plate motion changes (Hawaii-Emperor chain anyone?) I imagine also very important in the eventual death of a subduction zone. It is a nice example that shows how important processes at subduction zones are for the global scale plate motions.

Magma is formed by a melting process -- it is not everywhere! One can look at the chemistry and the petrology of the rocks and minerals to learn about the source of the magma and the processes it has been through. As acme states there are many types of volcanic eruptive styles. I'm no volcanologist, but: The traditional view is of a volcano sitting above a magma chamber. Melt feeds into the magma chamber from below, sits there, and every so often the pressure builds up to the point where it blows. In reality it's a bit more complicated than that, every volcano is different, there can be a network of chambers in some sort of plumbing configuration and many factors come into play when it comes to the eruption. The science has progressed a lot to the point now where we can predict volcanic eruptions (on some volcanoes) with some accuracy provided with good monitoring data. The dynamics of a volcano is a complex and active research area ...

Hi Acme, do you care to comment further on this?

An excellent point.

I realised that out of context this phrase could easily be misinterpreted. Let me rephrase: If (according to arc's model) the Atlantic has experienced periods of compression which formed the ridge, then where are all the compressional faults? I look forward to the creative reply. I cannot possibly comment on this as your description is very unclear. Perhaps your observational skills are not up to scientific standards? Perhaps it's just a case of severe confirmation bias? More confirmation bias and less hard thinking. These pulses have been observed elsewhere ... (I don't have the references to hand, though it might be interesting to dig them out) ... Interestingly, this is actually evidence against your hypothesis. Your hypothesis requires oceanic crust formation to stop and start. However, these studies clearly show that oceanic crust formation is constantly ongoing.