Pororoca is a natural phenomenon characterized by large and violent waves that are formed from the meeting of sea water with river water. There are several explanations for this phenomenon, but the main one says that its cause is due to the change in the phases of moon, especially on the equinoxes which increases the propensity of the net mass of the oceans providing large noise.
In the Amazon region, there is this elevation of water that reaches 6 meters in height at a speed of 30 kilometers per hour. You can predict the pororoca two hours in advance, as the force of the water coming from the headboard causes a very strong and unmistakable noise.
Moments before his arrival, the noise ceases and then silence reigns. This is the sign that it is better to find a safe place so that the force of the water does not cause any damage. Today, the pororoca has become a tourist attraction. Surf championships take place in Pororoca where the winner is the one who stays on the wave the longest.
Curiosities - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/curiosidades/o-que-e-pororoca.htm