Subject: Re: Every seventh wave on the sea.

* Is it true that every 7th wave rolling ashore from seas or oceans is * bigger that the other 6 waves? And if so, what is the explanation?

Waves breaking on the beach are generated at great distances from the shoreline. Factors such as the wind (weather), currents and the slope of the continental shelf all affect the propagation of waves through the ocean. Off the South Carolina coast (southeastern region of the US) we once calculated that roughly every 21st wave was larger than the previous ones, and the difference in height was approximately two-fold. I have heard that this phenomenon can vary among every 4 to 23 waves in the north Atlantic. The cause for these differences is attributed to a periodic 'catching up' of one wave with another. The single combined wave has an amplitude equal to the sum of the two individual waves, thus the two-fold difference in height.

-L. Bry, MAD.SCI Admin