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In the log of 14th April, 2005, Alex answered this question
- Jenna question about ocean waves [find original question]
Ocean waves are physically just the same as beach waves except that they don’t have a sloping beach under them. They are often much bigger – in the southern ocean they can build up over a fetch that goes right around the world, so each wave has enormous energy but the water itself is not moving forwards – only up and down.
But when the wave gets to a sloping shore, the lower part of it is deflected – slowed down – causing the wave form to collapse at the top and the water starts to surge forward – this is the breaking wave on a beach.
The same breaking effect is caused by the wind actually moving the water in the tops of ocean waves forwards, causing it to break – huge and very frightening if you are under it. Oceanographers may quibble with this description, but it’s more or less what happens.
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