Why do ocean waves go towards the beach?

The waves have a hypnotic effect. We can spend hours watching, without getting tired, how one after another breaks in front of the beach. You don't have to be very observant to discover that waves increase in height before they do so. To understand this phenomenon, the first thing we have to know is that wave energy has two components: potential and kinetic. Potential energy is related to height and kinetic energy is related to speed. And, contrary to what we might think a priori, waves do not transport water, but movement, so that when the wave has passed, the particles return to the same point. When there is a lot of speed, most of the energy is kinetic and as the wave approaches the coast, the potential energy predominates. In the open sea they have no direction. Sea waves are undulations that are generated on the water surface as a consequence of the propagation of movement between two media: water and wind. The highest part is known as the crest and the deepest part is called the valley or trough. If we focus on the movement, in sea waves we can distinguish two types: the oscillation of the medium moved by the wave - circular - and the propagation of the wave with a direction and speed. This is precisely what explains why not all waves travel at the same speed nor are they all equal. On the one hand, we know that the longer the time interval between waves, and at greater depths, the marine waves travel at greater speed. On the other hand, its size depends on the intensity of the wind, how long it has been blowing and whether it has a route in which there are no interruptions. In such a way that when there is no wind blowing it is said that the sea is calm, if the wind is light what is generated are waves of small millimeters in height (capillary waves) and if the wind is strong and constant what we observe are waves. big. All of this explains why in the open sea the waves do not have a predetermined direction; since there are no physical barriers, the wind can blow in all directions. However, this does not happen on the beach. At different speeds As the wave approaches the shore, the surface part travels faster than the deeper part, so that the crest ends up destabilizing and falling against the ground, producing a characteristic dull sound. And in shallow waters the speed of the waves is highly conditioned by depth: there is a certain moment in which the part closest to the bottom has a lower speed than that which is further away. This phenomenon is known as refraction and explains why waves die parallel to the beach line. There are also square waves. Year after year the French island of Ré, which is linked to Rochelle by a bridge, attracts thousands of tourists to photograph two events that have made it famous: its donkeys and its waves. And Ré's donkeys, since 1860, have worn beautiful pants to prevent them from being affected by insect bites to which they are very vulnerable due to their long and curly hair. MORE INFORMATION news No They find the progenitor of the largest 'magnetic monsters' in the Universe news No Russia reaches the orbit of the Moon: the final stretch begins to conquer the south pole of our satellite The other singularity is a gift from nature: the presence of square waves. This phenomenon, which is not exclusive to this French enclave, occurs when two sea currents collide with each other with great force and at high speed. In the case of the island of Ré, and a few kilometers below the water surface, the waters of the Cantabrian Sea collide with those from the Atlantic Ocean, producing this unique and photogenic visual phenomenon.