Extreme High Swell Events on the Moroccan Atlantic Coast

2.0 About High Swell Events » 2.7 More About Swell

Here’s some final information about swell.

The highest individual wave that is likely to be encountered in a storm is roughly twice the significant wave height. This height can be greater in rapidly changing conditions.

The energy level carried by waves varies depending on the state of the sea, with heavy storms producing waves of considerable power.

The power (P) of a wave is proportional to its period (T) times the wave height (H) squared, as given by the following formula:

P=0,4 * Hs² * T (kW per m).

The table shows just how much the power of a wave increases with relatively small increases in height. The important issue is that wave height can make a wave really powerful!

Beaufort scale

4

5

6

8

Hs (m)

1

2

4

6

T (s)

6

8

10

14

P (kW/m) (Power)

2.4

12.8

64

201.6

Question

Which system is more powerful?

Swell 1 = 320 kW/m and swell 2 = 640 kW/m. Therefore, swell 2 is more powerful than swell 1. Remember, P=0,4*Hs²*T (kW per m). When (T) doubles, the P (power) doubles. But when Hs doubles, the power (P) quadruples.

Please make a selection.