Talk:Ocean surface wave

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	Ocean surface wave is a former featured article candidate. Please view the links under Article milestones below to see why the nomination failed. For older candidates, please check the archive.
September 30, 2006 Featured article candidate Not promoted

Does the amount of water affect the size of the wave?

Certainly not. Water will deform continuously under shear so the amount (Volume basis) of water doesn't have a role to play in the size of the waves.

The image alignment of this page is somewhat odd. Could it be changed so that the text is next to the images?

Is a water wave's speed always the same (even if frequency changes) except for when depth changes? I read this formula: v=root(g x d) d=depth the characteristics of deep water waves. As such waves approach the shore they change their speed as the velocities under the waves start feeling the bottom. For surfing typically there is an obstruction that is at an angle to the incoming waves - some of the wave feels the obstruction and commences to break - the wave then bends into the break point feeding in more energy. If the angles are right you get a surfing wave. If it breaks too fast it closes out and you can't surf it.

What do you (anonymous contributor) mean by 'the amount of water'? Even the addition 'volume basis' doesn't ring a bell with me if it comes to propagation of waves. The formula is about the maximum speed of waves traveling through a basin with depth 'd'. You may already have found that waves with smaller wavelenghts travel at less speed than waves with greater wavelenghts but this rule only applies for waves that don't touch the bottom of the basin (that is to say waves with a wavelength less than twice the depth of the basin). Wikiklaas 22:44, 13 March 2006 (UTC)

In general the speed of the wave is a function of frequency and depth. This dependence on frequency goes away in shallow water. Jmkstrat 13:54, 28 May 2007 (UTC)

I do not like the "elliptical trajectory" diagram. Trajectories are never elongated in the vertical, as drawn, but always in the horizontal, and only when the water is shallow. Also, the dashed red trajectory should not extend higher than the tops of the crests. This same diagram is part of the Wave article, and I think it should also be changed there. Rracecarr 23:43, 10 May 2006 (UTC)

[edit] too many images, not enough text

images are taking over this page, perhaps they could be culled a bit, or more written to increase the words:image ratio?--naught101 06:08, 24 May 2006 (UTC)

I agree, there are way too many images in this article. It's been bothering me for quite a while, however I haven't had time to do anything about it. Adding more text isn't going to solve the problem though, the images are mostly out-of-context (at least misplaced). At the moment they're just adding fluff. If you want to do anything about it, I'll back you up. --Bruce 13:04, 25 May 2006 (UTC)

With that background I'll ask before making this change. Would my picture Waveface.jpg add something to the article? I believe it adds value in that it shows the shallow ocean floor where the wave breaks and how sand is being caught by and sucked into the wave when it breaks - and that this visually explains something fundamental about waves to the reader - but I don't want to add more pictures to this article if it is already overloaded. Elmats 12:32, 26 March 2007 (UTC)

[edit] Remove stub?

I added quite a bit to the page, in a little more layman's terms. Anyone vote for removing the stub tag? LACameraman 08:43, 24 May 2006 (UTC)

I noticed that the content you added was copied from "Anatomy of a Wave - By Jay Holben" (Google Cache). Are you Jay Holben? --Bruce 13:04, 25 May 2006 (UTC)

I am. I figured this didn't fall under the original research as that article was thoroughly researched. Also no copyright violation as I'm the original author of the original article. Hope that it helped to round out the article a bit. LACameraman 06:21, 26 May 2006 (UTC)

[edit] A new image

A particle motion in a ocean wave.
A=At deep water
B=At shallow water. The circular movement of a surface particle becomes eliptical with decreasing depth
1= Progression of wave
2= Crest
3= Trough

This is a modification of the image. I think it is better and more correct than the original. I've made it only for shallow water, but it is easy to do it for deep water too. I've chosen the numbers to facilitate the use in any language.(Internationalization)

Zimbres 21:08, 8 June 2006 (UTC)

Yes, definitely an improvement. Rracecarr 08:38, 9 June 2006 (UTC)

I concur, the illustration is clearer, but I question the reference to shallow or deep water. The expanded elliptical path of the object will be determined by wave steepness, not necessarily by depth of the water. If you're referring to particle motion at depth, that is an interesting note to make, but has to bearing on an article on surface waves. The illustration itself, however, is better than the existing one. LACameraman 09:58, 9 June 2006 (UTC)

Not sure what you mean, LACamera. In deep water the particle orbits are circles, and in shallow water they are squashed into ellipses. This does not depend on wave steepness. However, for steep waves, the orbits are no longer closed: water particles end up displaced a little in the direction of travel of the wave.Rracecarr 17:08, 9 June 2006 (UTC)

I've made one more modification in the picture. Now I think it is good for the article.Zimbres 21:53, 9 June 2006 (UTC)

The article is about ocean surface waves - not water particle movement in shallow or deep water - but movement on the surface of the ocean. The reference to particle movement at any depth, except on the surface, is not relevant to this article. The image is clearer than the existing one, but the references to different particle movement patterns at depth should be removed. LACameraman 00:33, 10 June 2006 (UTC)

Dear Lacameraman, one can't understanding how an ocean surface wave works if he doesn't understand its whole movement, including the particles movement. How explain, for example, the origin of the surf zone near the beaches? How understanding the wave breaking process? The ocean wave movement is made possible by small movements of the water molecules and the diagram is about that. Zimbres 14:34, 10 June 2006 (UTC)

Maybe it should be added that, in shallow water, the major axis of the ellipse tends to align itself with the floor (Biesel’s theory). Inike 13:32, 11 June 2006 (UTC)

I like new picture; it's a big improvement. I do have a couple suggestions. First, it might help to show the that for the shallow wave, the bottom of the ocean is at the "B". You might want to split the picture into two halves, one with a bottom and one without. Also, for the deep-water waves, the circle should decrease exponentially it size, rather than just disappear. But it would be pretty hard to make the difference clear in the picture, so you can ignore that :) Finally, the water surface should be should look more sinusoidal; the "traditional" wave shape is due to breaking, which is beyond the scope of that particular diagram. Bennetto 23:38, 4 July 2006 (UTC)

The picture is misleading. The results you quote about the particle paths being circular for infinite depth and elliptical for finite depth are only true in the LINEARISED limit for a monochromatic wave (the Stokes drift is a higher-order correction). Given that this is the case, the free surface shape of the picture is misleading. In the linear limit the waves shapes are simply sinusoidal, rather than having peaked crests and flattened troughs. 21 Feb 2007 —The preceding unsigned comment was added by 81.155.217.252 (talk) 20:57, 21 February 2007 (UTC).

[edit] Types of waves section

The 'Types of waves' section is out of tune with the start of the article. It is written in a 'popular' style and IMO should be rewritten or deleted. MH 20:00, 19 June 2006 (UTC)

As the author of the section in question, I would (of course) argue against deletion. The scientific section of this article, although excellent in and of itself, does not cover the topic nearly as completely without the section on Types of Waves. I do agree that the tone is different, but it is extremely difficult to compete with such a complex and hardcore mathematical approach, which I feel will alienate the majority of readers of this article. I am, of course, open to revisions in the section I added. If you feel you can match the tone and keep the information, please have my blessing. LACameraman 22:45, 19 June 2006 (UTC)

I believe both comments areappropriate. In preparation for a surfing weekend, I studied and did a sort-of rewrite on the (already pretty good) section, and will dl the box on the page. Sfahey 04:05, 22 August 2006 (UTC)

Ocean waves are inherently mathematical. They are one of the few phenomena described adequately by linear math. The math isn't that hard. User:jmkstrat

[edit] Fetch

Coorect me if i am wrong, but doesnt a longer fectch produce a larger wave, therefore that would be a destructive wave. Also a shorter fetch, makes a constructive wave because the wave has less energy to drag sediment back during the backswash. 88.108.26.22 13:42, 23 September 2006 (UTC)

This seems correct. Does the article say otherwise? Sfahey 02:20, 25 September 2006 (UTC)

Yes it does, it says that constructive waves are formed over a longer fetch and that a destructive wave is formed with a short fetch razza 14:54, 7 October 2006 (UTC)

[edit] Eighth Wave Question

I've always wondered why every eighth wave striking land is always the biggest. I can't find an answer anywhere. Does anybody know? I'd be grateful if someone could tell me on my talk page. Thanks! Robinoke 14:12, 1 October 2006 (UTC)

Waves tend to travel in groups. These waves have different frequencies and thus, when added together to create the free surface elevation, constructively and destructively interfere. The "eighth wave" (it may or may not actually be eight) is the largest wave of that group, being entirely due to constructive interference. As the waves enter shallow water, and their speed is no longer that dependent on frequency, they travel as a "locked" group, which is why it seems that the eighth wave is always the largest. Jmkstrat 13:54, 28 May 2007 (UTC)

[edit] Phase Velocity

The article describes phase velocity as the speed of movement of changes in shape. I believe this is not quite correct. The phase velocity is the speed of propogation of a phase change (ie change in phase angle). Shape changes can occur from amplitude (group velocity) and frequency of source. (Edit: Ill come back in a few days and modify it if there is no comment on this.) User A1 08:26, 4 October 2006 (UTC)

[edit] opening line

Apparently Ocean surface waves are surface waves that occur at the surface of an ocean. I changed this, hopefully to make it sound better and be a little bit less of a circular definition. Tell me what you think User A1 06:28, 1 December 2006 (UTC)

I think the correct terminology is "surface gravity wave(s)", as gravity is the restorative mechanism which enables the wave to propagate. This differentiates them from other wave phenomena such as "capillary waves", which are in fact surface waves but are driven by surface tension as the restorative mechanism. One can also observe capillary waves on the ocean surface but it is my understanding that this article refers to surface gravity waves. Michael.morristhomas 18:58, 18 December 2006 (UTC)

[edit] "Clapitus"

Can anyone shed any light on the origin and extent of use of the kayaking term Clapitus -- in that article? Thanks —The preceding unsigned comment was added by Clapitor creator (talk • contribs) 04:56, 19 January 2007 (UTC).

Clapitus is probably a miss-spelling of the French word clapotis. Kraaiennest (talk) 12:09, 4 February 2008 (UTC)

[edit] Wave close up

Hi,

I think there is no need for the wave close up in the section that you added it to. It does little to increase the reader's understanding of the types of wind waves possible. However the image is quite reasonable and obviously good effort has been expended in achieving it. Finally can you digitally edit (maybe just crop) the image to remove the giant date stamp on it? It detracts from the quality of the image (IMHO). Thanks, User A1 02:22, 1 June 2007 (UTC)

[edit] Merge in waves and shallow water

What do we think about merging the content of Waves and shallow water into this article? User A1 16:06, 14 September 2007 (UTC)

[edit] What about soliton waves?

The article Soliton mentions that solitary waves were first observed in water, in a barge canal by John Scott Russell. Here's a website about it. Should this be added to the article? How do soliton waves differ from ordinary water waves? --Chetvorno^TALK 00:53, 4 February 2008 (UTC)

Solitons only appear as surface waves in shallow water. In deep water, surface waves do not travel alone but in wave groups. On the other hand, solitons (or solitary waves) travel as a single wave of unchanged form.
Regarding the inclusion in this article: first, in my opinion, the name of this article is not so appropriate, since the phenomenon of waves on a water surface not only occurs in oceans, but in many open waters, like seas, lakes, rivers, etc. In this respect it is already significant that most photographs in this article are of breaking waves on beaches. No pictures of waves in the open ocean are present.
With the present name, I think solitons should not be included, since they do not appear on the surface of the ocean (although solitons may appear as internal waves on the interface between ocean layers of different density). Kraaiennest (talk) 12:04, 4 February 2008 (UTC)

[edit] are waves only in the ocean_

what determines whether there'll be waves in a place of water or not... in some rivers there seems to be waves or is that an innacuracey... do bays have waves... do rivers and canals... what about the thing with the moon... sorry my question mark on the keypad doesnt work... —Preceding unsigned comment added by 190.49.19.130 (talk) 18:07, 24 March 2008 (UTC)

In my opinion, you are perfectly right. Waves on a water surface also occur in rivers, lakes, canals and bathtubs, and they all obey to the same equations. The name of this article has not been well chosen. Crowsnest (talk) 20:44, 24 March 2008 (UTC)

[edit] Dangerous Waves

Waves poise a serious danger to people and property. Even non-Tsunamis are quite deadly. If the page is to be a FA it should have a section detailing the dangers. I have started edits, but can use other editors.--Lemmey talk 23:31, 4 May 2008 (UTC)

Waves may be dangerous, as well be fun (surfing), provide energy (wave power), give rise to forces, create beach erosion or accretion (littoral drift), etc. You are free to start a new section on wave effects, dangers and applications.

But this is an encyclopedia, and the added news item, how tragic it may be, is not encyclopedic. So I removed it. Crowsnest (talk) 07:19, 5 May 2008 (UTC)

[edit] Particle trajectories

The edits by InIn9393 (talk) on April 28 and May 4 are reverted by me, since they are not encyclopedic, using definitions which are uncommon to the literature on the subject, and due to the chosen definitions come to erroneous conclusions regarding the direction of the particle drift motion. The reference used by InIn1993 is a paper by Constantin (2006), Inventiones Mathematicae, vol. 166, p. 523. In the edits by InIn93 also references therein to earlier papers by Constantin seem to be referred.

1. According to the literature, trajectories of particles are closed ellipses within the framework of linear wave theory (see for instance: Landau & Lifshitz, vol. 6, 1986, p. 33; Lamb, 1994, p. 367; Phillips, 1977, p. 44; and many others). They all consistently apply the same linear theory, valid for infinitesimal-amplitude waves, also to computing the particle trajectories. In contrast, Constantin uses a nonlinear mapping to compute the particle trajectories for finite-amplitude waves, while using the flow field of linear wave theory. He concludes on grounds of this inconsistent (mixed linear and nonlinear) reasoning, that particle trajectories are not closed in linear theory, i.e. that after one wave period (as experienced by the particle) a particle ends at another position than where it started.
2. The fact that particle trajectories are not closed ellipses for nonlinear waves, was already established by Stokes (1847), using a (consistent) second-order (in wave amplitude) theory. This was extended to fully nonlinear waves in the 70's and 80's by many authors (e.g. Longuet-Higgins 1979, 1986; Williams 1981, 1985). They were well aware, that the Stokes drift in a nonlinear wave is due to the fact that the wave period experienced by a fluid particle in a Lagrangian frame of reference is different to the period of the surface elevation in an Eulerian frame of reference.
3. Constantin (2006) neglects that for nonlinear waves the definition of the wave phase speed is by no means unambiguous. In theory, any Galilean frame of reference may be used, some more reasonable than others. While Constantin poses on p. 526: "This leads naturally to Stokes' definition of the wave speed as the mean velocity in the moving frame of reference in which the wave is stationary.", Stokes (1847) poses a second definition which seems equally reasonable to him, i.e. the mean mass-transport velocity (depth-integrated horizontal-volume flux, averaged over a wave length and divided by the mean Eulerian depth), see p. 203 of his Papers, Vol. I (a reprint of the 1947 paper) . This definition of phase speed is at least equally valid, and in some respects even more natural (since for instance in laboratory wave flumes the mass flux is zero, and also for waves approaching normally to the coast the mean mass flux is zero).
   In case of Stokes' 2nd definition of wave celerity, i.e. a zero-mean mass flux, the fluid particles near the free surface drift in the wave propagation direction, while those near the bed drift in the opposite direction (contrary to the Constantin paper). This is the normal situation in a laboratory wave flume, for a wave made by a moving partition.
4. The "Science of waves" section is brief, and the inserted discussions on theories of particle orbits are out of proportion, in length, in depth and in relative importance for the subject, as compared to the rest of the section.

Crowsnest (talk) 14:25, 6 May 2008 (UTC)