======== Newsgroups: alt.surfing Subject: The Physics of Waves From: kmg@ix.netcom.com (Ketan Gadkari ) Date: 27 Mar 1996 05:55:07 GMT Hi, I am trying to learn more about how waves break. i.e. what equations drive how a wave will break. Do you know of any books on the subject and how to order them? Thanks, Ketan ======== Newsgroups: alt.surfing Subject: Re: The Physics of Waves From: Ric@diltd.demon.co.uk (Ric Harwood) Date: Thu, 28 Mar 1996 18:38:33 GMT Ketan Gadkari , kmg@ix.netcom.com (Ketan Gadkari ) wrote: >I am trying to learn more about how waves break. i.e. what equations >drive how a wave will break. Do you know of any books on the subject >and how to order them? In short, AIUI: In shallow water [h < L/20] the speed of waves is governed by the water depth rather than their wavelength, [as in deep water]. The shallower the water the slower they travel. However the energy of the wave must remain constant, [Newton] so as this energy is comprised of kinetic and potential forms, [speed and height] when the speed is decreased the height increases, but the wavelength does not change. The waves get bigger and steeper. There is a limit on how steep a wave can be, [H/L ~ 1/7] when it gets beyond this it starts to break, thus reducing the height. This tends to produce spilling breakers. Combined with this, as I said the speed of the wave depends on the water depth, so the crests of the waves travel faster than the troughs, [because the water is deeper] so the waves become asymmetric, with steeper fronts than backs. this increases the steepness of the face of the wave. Eventually the wave becomes unstable and the faster crest tries to overtake the trough and the wave breaks. This process tends towards producing plunging breakers, especially when it happens rapidly. These two processes act together, [along with other smaller and even more complex ones]. The extent of each depends on things like the rate of shoaling, hence you see plunging breakers [+ tubes] on steep beaches where the depth changes rapidly. h = water depth, L = wavelength, H = wave height. I have not gone into the equations too much, I can send you some if you wish {:^) But for more detail I would recommend: Introductory Dynamical Oceanography, 2nd Ed. 1983 Pond S. and Pickard G.L. Butterworth-Heineman Ltd, [Reed Elseiver] ISBN 0 7506 2496 5 HTH Regards, Ric -- ______________________________________________________________ PGP: 0x0766ABE5 | homepage http://area51.upsu.plym.ac.uk/~ric/ ======== Newsgroups: alt.surfing Subject: Re: The Physics of Waves From: mendo@ccnet.com (mendo) Date: 30 Mar 1996 20:13:36 -0800 For more reading, I'd also recommend _Waves and Beaches_. Unfortunately, I do not know the author. It is rather old, has very detailed information about all things related to waves and beaches, and has some amazing photographs. Greg mendo@ccnet.com ======== Newsgroups: alt.surfing Subject: Re: The Physics of Waves From: Ric@diltd.demon.co.uk (Ric Harwood) Date: Sun, 31 Mar 1996 21:57:45 GMT mendo, mendo@ccnet.com (mendo) wrote: > For more reading, I'd also recommend _Waves and Beaches_. >Unfortunately, I do not know the author. It is rather old, has very detailed >information about all things related to waves and beaches, and has some >amazing photographs. I think that it is in our library,. watch this space. Ric -- ______________________________________________________________ PGP: 0766ABE5 | Homepage http://area51.upsu.plym.ac.uk/~ric/ ======== Newsgroups: alt.surfing Subject: Re: The Physics of Waves From: skibo@florida.engr.sgi.com (Thomas Skibo) Date: 1 Apr 1996 00:34:48 GMT In article <4jl0pg$dga@ccnet3.ccnet.com>, mendo wrote: > For more reading, I'd also recommend _Waves and Beaches_. >Unfortunately, I do not know the author. Willard Bascom is the author. Good book. -- --- Thomas Skibo Silicon Graphics, Inc. skibo@sgi.com ======== Newsgroups: alt.surfing Subject: Re: The Physics of Waves From: nefcytom@aol.com (NefcyTom) Date: 31 Mar 1996 13:55:37 -0500 I have it written on my board. This was written by a physicist at UCLA. I will try to get an image of it to post here. The symbols do not translate very well. Tommy Nefcy Malibu surfer