"Square" waves, the angle between which can reach 90 °, is an unusual and bewitching sight. This phenomenon is called "cross-waves" or "cross waves". This natural phenomenon is not only beautiful but also extremely dangerous. It caused many shipwrecks. Let's talk about why "square" waves are formed, and why you should beware of them.
There are several reasons why "square" waves can appear in the sea
This often happens when the wind drives the waves in one direction and the sea currents in the other. Also, this phenomenon can be caused by the superposition of waves from different storms on top of each other. The third possible cause is wind shear. The changed wind sets a new direction for the waves, and they intersect with the already formed ones. The result looks like a checkerboard pattern on the ocean surface.
Scientists say the Cross Sea is an example of the Kadomtsev – Petviashvili equation in action. The formula describes nonlinear wave motion and is often used to explain how weather systems interact with each other.
Where can crosswaves be seen?
"Square" waves are most often found in shallow waters along coastal areas: on the beaches of the Azores, Tel Aviv and other regions. This is a fairly rare occurrence, but on the west coast of France there is one place where shear waves are generated with surprising regularity.
Promotional video:
Crossed waves on the island of Ré (Bay of Biscay, western France). Photo: National Geographic Russia.
This is the island of Re, whose geology is ideal for their formation. The sight of the waves attracts thousands of tourists to the island every year.
Why are “square waves” dangerous?
The powerful ocean currents that generate these unpredictable and unusually high waves (sometimes up to three meters in height) are capable of overturning large boats. Therefore, rescuers warn that under no circumstances should you go to sea in case of cross waves. If, for some reason, they suddenly appeared around you, you should get to the coast as soon as possible.
ELIZAVETA GRITSAI
