Talk:Plate tectonics

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NPOV[edit]

Please understand that I believe that the plate tectonics theory is correct, and I understand quite well why the article is locked. :)

Shouldn't the 'See Also' in this article include links to WP articles about opposing views (such as Flood Geology)? That page has been the subject of inappropriate edits [1] [2] that are apparently because of objection to opposing viewpoints having no mention here. Revent (talk) 03:16, 28 April 2013 (UTC)

No, we don't need links to fringe articles just because some true believer objected there. Flood geology is not an opposing view - it's religious pseudoscience. Vsmith (talk) 15:28, 28 April 2013 (UTC)
Regardless of it's status as religious pseudoscience, it is a set of opinions held by many people (hence it's worthiness for a WP article) that directly contradicts the content of this article. IMO, not at least mentioning it in the 'see also' (which is the least 'significant' way to mention it) is essentially inappropriate. The fact that a large number of people hold an opinion that contradicts this theory is itself notable, and a member of the public reading this article would probably be interested in that. If you read Flood Geology, you'll see that it is mentioned in the lead that the scientific community considers it to be pseudoscience.. History_of_geology also links to flood geology, and discusses that it's development as a 'theory' was a direct stimulus for the increased research into the Earth's age that led to the development of plate tectonics. Revent (talk) 20:41, 28 April 2013 (UTC)
To be more specific, from History_of_Geology, 'To prove the Bible’s authenticity, individuals felt the need to demonstrate with scientific evidence that the Great Flood had in fact occurred. With this enhanced desire for data came an increase in observations of the Earth’s composition, which in turn led to the discovery of fossils. Although theories that resulted from the heightened interest in the Earth’s composition were often manipulated to support the concept of the Deluge, a genuine outcome was a greater interest in the makeup of the Earth.' Revent (talk) 20:44, 28 April 2013 (UTC)
Its not worth putting on the page, because the folks you talk about have no actual evidence, just opinion. Its the same reason we don't have a section devoted to Alchemy on the Chemistry page, or Astrology on the Astronomy page. 74.132.252.16 (talk) 06:01, 20 May 2013 (UTC)

Plate tectonics and rotation circa 2005[edit]

The main article in 2005 contained absolutely no details relating to a rotational mechanism for crustal evolution/motion even though this mechanism was being considered using specific reasoning in that year.The mechanism based on an uneven rotational gradient between equatorial and polar latitudes known commonly as differential rotation is almost a 100% certainty for all celestial objects with rotating fluid compositions so it is really no stretch of the imagination to apply it to the Earth's interior and look for clues on the surface crust and the 26 mile spherical deviation of the Earth relating to this mechanism.The Wikipedia article as in now stands amounts to flinging every assertion possible using rotation without the neat reasoning which actually requires researchers to consider fluid dynamics via the spherical deviation of the planet or the necessity to explain the Mid Atlantic Ridge using the global lag/advance mechanism arising from differential rotation where there is a symmetrical generation of crust either side of the Great Ridge.This is not a matter of priority or attribution,it is most certainly about wrecking an approach to a rotational mechanism in a measured and reasoned way as it was done long before rotation was inserted as wild and indiscriminate assertions years later.78.137.181.121 (talk) 05:34, 17 May 2013 (UTC)

Without a source, it's difficult to comment on - not that I entirely understand what you're asking for. Mikenorton (talk) 07:11, 17 May 2013 (UTC)

You are fine,eventually they will discover that it is impossible to exempt the Earth rotating fluid interior from the 100% certainty of differential rotation and even if they do apply it to evolutionary geology and specifically oceanic crust generation/destruction without proper attribution they will sooner or later run into the spherical deviation of the planet from the same cause.How many times have they to repeat 'the debate is still open' when academics should be handling the rotational principles with confidence and competence.Orion216 (talk) 19:05, 30 May 2013 (UTC)

Considering that CME's expose the Venutian bow shock due to the residual rotation of Venus as opposed to the magnetic field created by the Earth's rapid rotation which protects the surface from such pronounced bow shocks, the person who removed all content relating to rotation and plate tectonics because it interferes with a stationary Earth notion of 'convection cells' and a flawed notion of a high viscosity fluid in contact with the fractured crust is basically sledgehammer editing. Obviously researchers haven't looked at the viscosity of the fluid pouring out of every volcano and boundary in order to work with a lower viscosity and differential rotation across latitudes.

https://www.youtube.com/watch?v=fmCJSS2YAP0

Orion216 (talk) 15:53, 18 November 2015 (UTC)

A discussion about a rotational mechanism based on differential rotation across latitudes shouldn't suffer from the concerns of an academic curia so perhaps it is better to just isolate the approach and leave it for what it is. The geologically active and very volcanic Venus has no plate tectonics, no spherical deviation and only residual rotation whereas our home planet rotates at a fairly decent clip , has a noticeable spherical deviation and a very active crust. It is only a matter of drawing comparisons and creating a narrative suitable for the evolution and motion of the surface crust on Earth along with observations of the viscosity of the fluid pouring out of every volcano and boundary. It is a shame that a rotational mechanism is going to be smothered by the academic curia who expect and invoke reference warfare as a 'debate'. No complaints here as I enjoy the challenge of advancing the geological puzzle as the facts present themselves.Orion216 (talk) 07:12, 24 November 2015 (UTC)

error in estimate of thickness of oceanic lithosphere?[edit]

The article currently states that "average oceanic lithosphere is typically 100 km (62 mi) thick; its thickness is a function of its age: as time passes, it conductively cools and become thicker." In general, things do not expand upon cooling (one exception is water from 0-4˚C), and I think the above statement, and possibly the thickness estimates, are not correct. — Preceding unsigned comment added by Chouwawa (talkcontribs) 00:52, 10 September 2013 (UTC)

What could perhaps be made clearer is that the thickness increases as the lithosphere cools because more of the mantle becomes part of it - the base of the lithosphere is determined approximately by the temperature, as this affects the strength, with marked weakening at temperatures above about 1300°C. Mikenorton (talk) 06:53, 10 September 2013 (UTC)
Reworded a bit "its thickness is a function of its age: as time passes, it conductively cools and subjacent cooling mantle is added to its base" to (hopefully) clarify the confusing wording. Vsmith (talk) 12:41, 10 September 2013 (UTC)

Downward suction???[edit]

Lede claims downward suction is a significant force. Risible.173.189.79.137 (talk) 16:41, 12 October 2013 (UTC)

I know neither you nor Lede, but indeed, slab suction is a significant force, greater in magnitude than ridge push. That's why the atlantic ridge that is solely driven by ridge push spreads at a speed of approx 2cm/y when the pacific that has bothe the western american and eastern asian subductions to push on it moves at approx 10 cm/y
Quite not risible 140.77.130.227 (talk) 21:55, 24 March 2017 (UTC)

Semi-protected edit request on 13 February 2014[edit]

Alfred Wegener's name should be linked to his wiki page in the summary of the development of the theory:

Summary


Detailed map showing the tectonic plates with their movement vectors. In line with other previous and contemporaneous proposals, in 1912 the meteorologist Alfred Wegener amply described what he called continental drift, expanded in his 1915 book The Origin of Continents and Oceans[28] and the scientific debate started that would end up fifty years later in the theory of plate tectonics. https://en.wikipedia.org/wiki/Alfred_Wegener A low-carb high fat dieter (talk) 17:51, 13 February 2014 (UTC)

X mark.svg Not done This would contravene WP:OVERLINK which states:-
Generally, a link should appear only once in an article, but if helpful for readers, links may be repeated in infoboxes, tables, image captions, footnotes, and at the first occurrence after the lead.
Alfred Wegener's name is already linked twice in the article - so for strict compliance, one of those links should be removed, but that is rather petty. - Arjayay (talk) 18:10, 13 February 2014 (UTC)

Summary missing original text?[edit]

Looking at the summary section, I was somewhat surprised not to see Antonio Snider-Pellegrini's work as the original theoretical text behind plate tectonics. Is this an omission or was it specifically left out? Ckruschke (talk) 09:49, 10 March 2014 (UTC)Ckruschke

He's mentioned in the Continental Drift section "Wegener was not the first to note this (Abraham Ortelius, Snider-Pellegrini, Eduard Suess, Roberto Mantovani and Frank Bursley Taylor preceded him just to mention a few)". The lead section just mentions that the theory "builds on the concepts of continental drift", which seems like a sufficient summary to me. Mikenorton (talk) 19:12, 10 March 2014 (UTC)
Weak agreement - Wegener's work is the foundation and I guess it is ok if none of his predecessores are listed in the section summary para (it isn't the lede).
Follow-up question - this sentence is just following the sentence you cite above "but he was the first to marshal significant fossil and paleo-topographical and climatological evidence to support this simple observation." with italic emphasis on the statement that he was the first to note fossil evidence supporting his theory. Snider-Pellegrini's work also notes fossil evidence as the basic proof behind his theory. Is the hair that is being split here is the word "significant"? I have not read the works of the other authors (Suess, Mantovani, et al) so am unsure if Snider-Pelligrini is the only one that made the fossil - plate tectonics connection prior to Wegener's work. Ckruschke (talk) 02:47, 11 March 2014 (UTC)Ckruschke

George Plafker and the '64 Alaska quake[edit]

There is a good article in the NY Times ("A '64 Quake Still Reverberates". New York Times.  ) that has some material that might be worth incorporating here or in the article on earthquakes; apparently, before the '64 quake, the connection between plate tectonics and earthquakes was still controversial. Paulmlieberman (talk) 21:16, 8 April 2014 (UTC)

Note: removed the reference tags and formatted as inline link. Vsmith (talk) 21:13, 6 October 2014 (UTC)

who is David Pratt?[edit]

I keep seeing websites by this geologist (?) who says that there are serious issues with plate tectonic theory, making it sound like there is a sizable voice in geology against plate tectonics. Why are they not included in the article? Givethemahug (talk) 03:05, 29 June 2014 (UTC)

He expresses a decidedly WP:FRINGE view. Most of his work is either self-published or appears in New Concepts in Global Tectonics, a newsletter whose editorial board he is on. His ideas have not been picked up by geologists in general and I see no reason to mention them here. Mikenorton (talk) 06:30, 29 June 2014 (UTC)

Grand Canyon part[edit]

Hello everyone. I'm D011235813d. i would like to remove the "grand canyon" section from the page plate tectonics because I think it is not related, in any way, to plate tectonics. Please give any suggestions, answers, or tips to me as soon as possible. Thank you for your time. D011235813d (talk) 19:30, 6 October 2014 (UTC)

The "Grand Canyon" part is simply the illustration for the template Key topics in Geology and is not implying a relationship, altho' the development of the canyon is definitely related to the tectonics of western North America. (note: I've removed the template from this talk section.) Vsmith (talk) 21:08, 6 October 2014 (UTC)

Fix for description of Types of Plate Boundaries: Convergent Boundaries[edit]

The text uses the phrase "continent-to-continent subduction ". Shouldn't this be "ocean-to-continent subduction", since the two examples given are of the Nazca oceanic plate subducting under the South American continental plate, and the Juan de Fuca oceanic plate subducting under the North American continental plate. Continental collision is described in a separate set of sentences. 192.4.0.12 (talk) 18:27, 25 November 2014 (UTC)

Done - thanks for pointing that out. Mikenorton (talk) 20:25, 25 November 2014 (UTC)

Driving forces related to Earth rotation[edit]

For point #5, I suggest reference to the Earth ellipsoid, because more than 99% of georadial adjustments resulting from secular axial motion (i.e. polar drift) accrue from deviations of the reference ellipsoid from a sphere. Less than 1% accrue by gravitational differences from mass related variations. The change in emphasis is important as more is being accomplished, lately, by utilizing 'ellipsoidal demand'. Ref: Please select latest draft: http://www.celestialgeodynamics.org/content/los-angeles-san-francisco

Thank you for your consideration, Douglas W. Zbikowski

75.171.52.16 (talk) 23:07, 19 January 2015 (UTC)

When your work has been published in a peer reviewed journal and had a significant impact - then perhaps ... Vsmith (talk) 23:25, 19 January 2015 (UTC)

Revisiting driving forces related to Earth rotation[edit]

There are quite a few problems with this section of the article, and at one point I removed the entire section, only to see an avid editor restore it. I don't have time to go into all of it, but the main and most explicit problem is the assertion that the Coriolis force is actually a significant factor in plate tectonics. It isn't. Plate motion is, ultimately, driven by mantle convection, and the important factors affecting that convection are viscosity, thermal buoyancy, and pressure. Inertia and the Coriolis force are not important. This is explained very clearly in two authoritative references that, yesterday, I inserted into the article. See page 36 of Ricard,[1] or page 149 of Glatzmaier[2]. Another problem with the section is the mistaken notion that the centrifugal force is important for plate tectonics. Once again, it isn't. The centrifugal force for mantle convection is, yes, larger than the Coriolis force, but still relatively small compared to viscosity and thermal buoyancy. There is an interesting introduction to these sorts of issues starting on about page 11 in Bercovici[3]. Generally, the centrifugal force just distorts what would be an approximately spherical gravitational potential into a gravitational+centrifugal potential with a shape that resembles an oblate spheroid, resulting in convection that is only slightly different from a spherical convection, see page 36 of Ricard.[4] Now, yesterday I tried to insert some of these sourced concepts into the text of the article. I also removed the unsourced and erroneous material that has, I understand, been in the article for years. Unfortunately, I've been reverted. So, here I am justifying what I did: I removed unsourced material and substitute sourced material. The sourced concepts I've explained above should be, in my opinion, restored. The erroneous material should be removed. Thank you, Isambard Kingdom (talk) 14:14, 23 November 2015 (UTC)

The issue is differential rotation displayed by all rotating celestial bodies with exposed viscous compositions and not an appeal to Coriolis. The ideology of 'convection cells' ignores the rotating Earth hence a high viscosity fluid was thereby asserted to account for convection effects on the evolution and motion of the surface crust whereas a lower viscosity and differential rotation across latitudes produces clues on the surface crust consistent with a rotational mechanism such as the Mid Atlantic Ridge. The biggest planetalogical feature is actually the 26 mile spherical deviation between Equatorial and Polar diameters and this meshes nicely with the uneven rotational gradient between Equator and poles. I imagine this is why the tendency is now towards the rotation of the fluid interior impacting on the surface crust and why editors are now reluctant to see a hatchet job done on the speculative rotation mechanism by invoking a stationary Earth notion of 'convection cells'. In short, if you can exempt the Earth's fluid interior from differential rotation of the fluid across latitudes even though it is attested for all rotating celestial bodies with viscous states then and only then can you posit 'convection cells' for plate tectonics.Orion216 (talk) 21:23, 23 November 2015 (UTC)

I've restored the referenced content as added by User:Isambard Kingdom. You will need to supply references directly relevant to the article to support your concerns above. Please also see WP:synthesis. Vsmith (talk) 02:52, 24 November 2015 (UTC)

I must conclude from the vivid discussion that my original statement that the discussion is still open stands. Any force related to Earth Rotation has since long been debated and I think it is therefore correct to leave the Article in some form here. It needs to be mentioned with the correct references to the articles that both promote certain forces and others that deny their existence as relevant in Plate Tectonics. Wikipedia has even entire articles related to highly discussed Earth Science and does not position itself necessarily. I thanks everybody so much for contributing and adding references. Jpvandijk (talk) 09:26, 7 December 2015 (UTC)

The references below manage to exempt the Earth's rotating fluid interior from differential rotation across latitudes even though every observed rotating celestial object in a viscous state will display that dynamical feature.'Convection cells' are basically a stationary Earth notion hence the decision to move forward will be a choice between differential rotation or convection cells. If the contributor can find a rotating celestial object in a viscous state that displays only convection then and only then can the debate be closed but they would still have to account for the spherical deviation of the planet using those cells. Orion216 (talk) 21:42, 8 December 2015 (UTC)

References

  1. ^ Ricard, Y. (2009). "2. Physics of Mantle Convection". In David Bercovici and Gerald Schubert. Treatise on Geophysics: Mantle Dynamics. 7. Elsevier Science. 
  2. ^ Glatzmaier, Gary A. (2013). Introduction to Modeling Convection in Planets and Stars: Magnetic Field, Density Stratification, Rotation. Princeton University Press. 
  3. ^ David, Bercovici (2009). Treatise on Geophysics: Mantle Dynamics. 7. Elsevier Science. 
  4. ^ Ricard, Y. (2009). "2. Physics of Mantle Convection". In David Bercovici and Gerald Schubert. Treatise on Geophysics: Mantle Dynamics. 7. Elsevier Science. 

Semi-protected edit request on 14 December 2015[edit]

The article should be revised to reflect the latest tectonics understanding based on:

Swedan NH. Ridge Push Engine of Plate Tectonics.Geotectonics, 2015, Vol. 49, No. 4, pp. 342–359. © Pleiades Publishing, Inc., 2015.

The tectonic plates are driven be forced convection of the upper mantle, which performs as a thermodynamic cycle. Midocean ridges enclose a magma chamber that acts as engine chamber. The latent heat of solidification of the new ocean crust is released inside this chamber and it is converted into mechanical work that drives the tectonic system. The tectonic plates perform as pistons and piston rods. Mechanical energy is thus transported from the ridges into oceanic trenches.

Ridge push and slab pull cannot explain the rise of colossal mountains such as the Rockies or Hamalyians. On the other hand, the thermodynamic engine at pressure of 5,000 bars at midocean ridges can explain continents building.

Nabilswedan (talk) 05:43, 14 December 2015 (UTC)

No, Wikipedia is not here to promote your work. Vsmith (talk) 14:50, 14 December 2015 (UTC)

Semi-protected edit request on 14 January 2016[edit]

In section "Types of plate boundaries" "3. Convergent boundaries" delete "and as the subducted plate partially melts". Begin a new sentence and replace with "The mantle above the subducting plate partially melts as water is driven off the dehydrating subducting plate". This is a very common misconception among students that is not helped by being repeated here. Only in rare cases does the subducting plate melt. 137.113.101.15 (talk) 21:03, 14 January 2016 (UTC)

Ultimately the subducted plate does melt as it becomes entrained into the convecting mantle. Still, it is as also true that there is partial melt associated with dehydration. Do you have a standard source we can cite?Isambard Kingdom (talk) 21:12, 14 January 2016 (UTC)
Partial melting of the mantle below volcanic arcs is caused by the release of volatiles (mainly H20) from the descending slab. This paper is pretty comprehensive - maybe too detailed in fact. Some other sources The subduction factory and Turcotte & Schubert. Mikenorton (talk) 21:48, 14 January 2016 (UTC)
Yeah, the article is wrong and it should say that the magma that comes up originates in the mantle wedge, not so much the descending slab, and that the actual melting is from changing the melting the point of the wedge, not by heating the slab. That's something that gets emphasized in Earth Science 101 curricula but which is also counterintuitive for most people, and it's tricky to describe melting point depression to a non-technical audience. Is everyone happy with this edit? [3]. Thank you for noticing that, IP editor. Geogene (talk) 23:26, 14 January 2016 (UTC)
I've removed some text a bit further down that section that said similar stuff to your edit - the text of this whole section still needs tightening I think. Mikenorton (talk) 00:13, 15 January 2016 (UTC)
Pictogram voting question.svg Question: So has this SPER been fulfiled? Or should this remain open? Ping me with repsonse, thanks. --allthefoxes (Talk) 03:37, 15 January 2016 (UTC)
Pictogram voting comment.svg Note: Closed for now --allthefoxes (Talk) 22:19, 16 January 2016 (UTC)

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