Talk:Continental drift

From Wikipedia, the free encyclopedia

Contents 1 Continental drift term 1.1 Article topic is Wegner's time period 2 Ocean size 3 Subarticle? 4 Sunken Continents vs. Continental Drift 5 first?

[edit] Continental drift term

The best out of this material would suit the 'history' subsection at Plate tectonics instead of being isolated under this antiquated expression, IMO. More findable I think. Wetman 04:42, 12 Jan 2004 (UTC)

[edit] Article topic is Wegner's time period

I think that this term is important for its historical value. It is anachronistic to discuss Wegner's theory as plate tectonics, since the term was invented over 30 years after his death. This article should be about the development of the concept of continental drift separately from that of plate tectonics. Although this article needs further work (e.g., Various data) Gwimpey 23:16, 5 May 2004 (UTC)

I am going to add some info on pre-Wegner continental drift hypotheses based on info in Geology in the Nineteenth Century by Mott T. Greene Gwimpey 23:54, 9 May 2004 (UTC)

[edit] Ocean size

I think that the ocean in fact does not get bigger because of plate tectonics. If the magme spreads the plates apart and creates more oceanic crust, then the oceanic plates will just go below other plates and the ocean will get new crust and lose old crust. I do think, however, that the land masses will get bigger from the rifts on the land and the land plates will go over all the oceanic crusted plates.

No, the Pacific ocean is in fact getting smaller. This is because it has more convergent than divergent boundaries, so more material is being "destroyed" than "created". Conversly and consequentially, the atlantic ocean is growing because the mid-ocean range goes thorugh the atlantic ocean. The ocean as a whole is not shrinking, if that is what you mean. But specific oceans are shrinking due to their plate boundaries. -Anonymous

Whether ocean gets bigger depends upon everything else. India merging with Asia surely takes less surface area than did a separate India. But various volcanic islands have grown, rivers have dumped sediment, the South Atlantic has moved Africa and South America apart, the Rift valley in Africa is opening, etc. (SEWilco 02:45, 28 Apr 2005 (UTC))

VIKTORIA SIUHA GR 8

hi i am viktoria and i think that the ocean is about the half size of the world cause the earth is half water and it can not get bigger cause of its plate crusts and hopefully one day we will all get the chance two really explor just how big is the ocean

Please stay on topic, and for the love of my sanity, use proper grammar and spelling.

[edit] Subarticle?

There is a link stating that this is a subarticle of plate tectonics [1] but this article contains a link stating that plate tectonics is a subarticle of this article.[2] Is this article a subarticle? (SEWilco 5 July 2005 07:26 (UTC))

[edit] Sunken Continents vs. Continental Drift

My edition is not 'original research' as every sentence and conception conveyed is sourced, and less even are 'inappropriate'. The articles are scientific peer-reviewed; due to deletions in this and other articles I copy it to here for those who really want to make scientific research and not scientific politics. Regards --GalaazV 23:56, 14 February 2006 (UTC)

---

See main article Vertical tectonics.

Continental drift theory far from being a simple, elegant, all-embracing global theory, it is confronted with a multitude of observational anomalies, and has had to be patched up with a complex variety of ad-hoc modifications and auxiliary hypotheses. The existence of deep continental roots and the absence of a continuous, global asthenosphere to 'lubricate' plate motions, have rendered the classical model of plate movements untenable. There is no consensus on the thickness of the 'plates' and no certainty as to the forces responsible for their supposed movement. The hypotheses of large-scale continental drift, seafloor spreading and subduction, and the relative youth of the oceanic crust are contradicted by a considerable volume of data. Evidence for substantial vertical crustal movements and for significant amounts of submerged continental crust in the present-day oceans poses another major challenge to plate tectonics.

A major new hypothesis of geodynamics ^[3] is surge tectonics, which rejects both seafloor spreading and continental drift. Surge tectonics postulates that all the major features of the earth's surface, including rifts, foldbelts, metamorphic belts, and strike-slip zones, are underlain by shallow (less than 80 km) magma chambers and channels (known as 'surge channels'). Seismotomographic data suggest that surge channels form an interconnected worldwide network, which has been dubbed 'the earth's cardiovascular system'. Active surge channels are characterized by high heat flow and microearthquakes. Magma from the asthenosphere flows slowly through active channels at the rate of a few centimeters a year. This horizontal flow is demonstrated by two major surface features: linear, belt-parallel faults, fractures, and fissures; and the division of tectonic belts into fairly uniform segments. The same features characterize all lava flows and tunnels, and have also been observed on Mars, Venus, and several moons of the outer planets. Surge tectonics postulates that the main cause of geodynamics is lithosphere compression, generated by the cooling and contraction of the earth. As compression increases during a geotectonic cycle, it causes the magma to move through a channel in pulsed surges and eventually to rupture it, so that the contents of the channel surge bilaterally upward and outward to initiate tectogenesis. The asthenosphere (in regions where it is present) alternately contracts during periods of tectonic activity and expands during periods of tectonic quiescence. The earth's rotation, combined with differential lag between the more rigid lithosphere above and the more fluid asthenosphere below, causes the fluid or semifluid materials to move predominantly eastward.

References

1. ^  Pratt, David Sunken Continents versus Continental Drift, Plate Tectonics: A Paradigm Under Threat first published in the Journal of Scientific Exploration, vol. 14, no. 3, pp. 307-352, 2000

_______________

Dubious at best. Ref links are to compuserve userpage for one David Pratt. The ref Journal of Scientific Exploration appears to be a place to get your wild ideas and speculations published - peer reviewed by what peers? If it wasn't bunk it would be published in a real journal. The J of Sci Expl. publishes stuff on bigfoot and re-incarnation, unlikely bedfellows for a serious geophysics article. In other words nonsense! Now, there are unanswered questions and plenty of room for new research related to plate tectonics - it is a vibrant living science and new discoveries and controversies are there. If the controversies have validity, they will be published in true peer reviewed journals. I say begone with it - or write an article for it properly labeled as speculation and pseudoscience - along with the flat and/or hollow earthers. Vsmith 00:48, 15 February 2006 (UTC)

I agree. It seems strange to me. Bubba73 (talk), 01:09, 15 February 2006 (UTC)

The subject matters published in the journal are immaterial to the validity of the theory, which is lacking. A better rebuttal is that every observation is against it. Thus, it's junk. A nice fiction, yes, but a fiction nonetheless. Whether or not Atlantis did exist has nothing to do with the validity of this theory, that's for sure. Why don't we notice the continents now sinking down or rising up? Because maybe they don't do that? Hmm... "Vertical tectonics" = "Vertical bunk". Oh, and Plato never said Atlantis was a continent, too... 170.215.83.4 00:04, 29 November 2006 (UTC)

After a bit more looking at D. Pratt's c-serve page, I'd say add the nonsense to Theosophy - check out his site, hilarious [4] :-) Vsmith 01:20, 15 February 2006 (UTC)

[edit] first?

The article opens "Continental drift, first proposed as a theory by Alfred Wegener". According to Drifting continents and shifting theories by H. E. LeGrand, Wegener was not the first to propose drift. He gives a very interesting history. I'm up to chapter 5 in the book, but there are quite a few things about (1) the history and (2) Wegener's evidence that I intend to put in the article. Bubba73 (talk), 04:52, 13 December 2006 (UTC)