The book Tidal Lands published 1918, mentioned in the blog of 6th May, uses the phrase ‘wind waves’ rather than just waves, although it doesn’t go into waves fluid dynamics but rather the effect of waves on various types of coastline. The size (height) of wind waves is mostly determined by the wind prevailing over the surface of the water-body,, how long in time that that wind has been blowing and how strongly the wind is blowing (wind speed). The other determining factor is the ‘fetch’, that is how far across the water body the wind has been blowing. The picture above shows a point on the Portuguese coast (from the internet), here the fetch could potentially be 2000 miles giving the potential for stormy coastal conditions. No point on the coast of the North Sea could be impacted by such a fetch but destructive ‘surges’ originate in the Atlantic and pass down the east coast of Britain and on to the south North Sea coastlines, so in fact on such occasions North Sea coasts are impacted by the long fetch of the Atlantic Ocean. Witness the 5th December 2013.
Waves can be ‘constructive’ or ‘destructive’. In the former the waves are placid, relatively calm conditions, and the ‘swash’ carries fine sediment particles onto the beach thus, over time, adding to the bulk of the sandy beach. Destructive waves are characteristic of storm conditions, here the ‘backwash’ is more powerful than the ‘swash’ thus eroding fine material from the beach back onto the sea-bed.
But I still have an unanswered question.
(To be continued).