Sea surf It is a natural phenomenon characterized by the abnormal rise in sea level, in addition to the increased agitation of its waters. A hangover is caused by instability in the weather, such as during the passage of a cold front or a cyclone. Furthermore, tides also cause undertows. This phenomenon results in waves of great amplitude that break on the shore or advance over the beach, which can affect the balance of coastal environments, damage infrastructure and pose risks to population.
Read too: How does a tidal wave form?
Summary about sea hangover
Sea hangover is an oceanographic phenomenon characterized by the abnormal rise in sea level and the agitation of its waters.
The waves generated during a surf break on the shore or advance over the beach, which can cause flooding.
Its main causes are the approach of tropical or extratropical cyclones and also cold fronts. They can also originate from the tides.
Sea surges intensify coastal erosion and damage more fragile coastal environments.
They pose risks to swimmers and boat drivers. If water advances over the beach and the city, storm surges cause damage to infrastructure and generate economic losses.
What is a sea hangover?
Sea hangover is the name given to the natural phenomenon characterized by an abnormal increase in the level and from the agitation of the waters from the sea, O which causes very strong wavesand of great amplitude that propagatetowards the beach and break violently on the shore or advance over the sand and coastal infrastructure, causing floods.
The name “ressaca” for this movement of waves advancing on themselves comes from the Spanish word hangover, which refers to the sea current created with the rapid advance and breaking of sea waves from the coast.
Causes of sea hangover
A sea hangover is a phenomenon that occurs in the oceans, and its effects are felt directly on the Earth's surface, notably in coastal cities. However, this is a type of occurrence whose causes presentmeteorological nature, which means that they are associated with atmospheric and also astronomical weather. In the second case, the hangover is caused by the intensification of the tides.
To the weather conditionsin a certain area affect the behavior of sea waves, especially when there is high atmospheric instability. During the approach of cold fronts, for example, or when typhoons and tropical cyclones or extratropical, Thepresence of strong winds over the oceans causes the surface layer of water to be “pushed” (sea current), causing agitation in the sea and generating many waves during its passage.
See too: Sea currents — how they form and what their relationship is with the climate
How does a sea hangover happen?
In the previous topic, we saw that sea hangovers are mainly caused by instability in atmospheric weather. Intense storms that characterize the passage of typhoons and cyclones, as well as the approach of cold fronts, marked by high-speed winds, are capable of producing the hangover phenomenon.
The winds blow over the sea water, causing it to be pushed and a sea current is created. Waves originate from this movement which gradually increase of amplitude as they propagate towards the beach line, which causes a rise in the water level in regions close to the coast. During a hangover, the waves advance on themselves until they break in the surf zone, which is precisely the beach area where the waves dissipate.
These waves that hit the beach can be more than 3 feet tall, as happened in the city of Rio de Janeiro and on the coast of the state of São Paulo in November 2023 due to the passage of an extratropical cyclone. As they reach the dissipation zone with great turbulence and amplitude, the waves they break with violence or else they advance on the sand It is invade (or flood) the beach and the surrounding infrastructure, such as streets, avenues and residential or commercial neighborhoods.
To the Astronomical tides are also the cause of sea hangovers. In this case, it is the action of the Moon's gravity (Earth's natural satellite) that “pulls” the sea waters at a certain point, causing an increase in the level and greater agitation, causing waves of greater amplitude than in periods of relative stability. It is worth remembering that the position of the Moon in the sky and the stage it is in directly influence the occurrence of tides more intense or weaker.
How long does a sea hangover last?
The duration of the sea hangover is variable. Those associated with astronomical tides, caused by the action of the Moon's gravity on the oceans, remain active during the night. The hangover that is caused by atmospheric instability lasts as long as the cell that conditions changes in the weather is over that area, can be active per a few hours or days.
Know more: Is it possible for a tsunami to occur in Brazil?
Consequences of sea hangover
The consequences of sea hangovers vary depending on the intensity and range of the waves, as well as aspects of the area where they occur, which can only affect the physical structure of the soil and rocks or cause damage to the city's infrastructure and generate damage and losses to the population. Taking this into consideration, the consequences of a sea hangover are:
erosion coastal due to the effect of water on bare rocks;
intensify erosion in fragile environments, such as occupied sand strips;
change, even if temporary, in the position of the coastline;
removal of beach vegetation and changes in the dynamics of this environment;
greater risk of drownings and disappearances of bathers;
dragging structures mounted on the beach sand, such as tents, umbrellas, etc.;
dragging of people and animals that are on the beach during the surf;
flooding of both the beach and the asphalt, damaging traffic and vehicle structures;
damage to urban infrastructure, such as poles, streets, sidewalks, walls;
flooding of commercial establishments, buildings and residences.
Not only that, but this phenomenon also poses a risk to fishermen and boat crews and drivers. In many cases, depending on the strength of the waves, Hangovers can cause people to disappear and even die due to drowning or associated causes, such as falls.
→ How does sea hangover affect the lives of those who live on the coast?
Living on the coast, closer to the beach, has numerous benefits for those who enjoy this condition, especially in terms of quality of life. However, there are natural phenomena typical of these areas that directly affect people's daily lives, such as sea hangovers.
In addition to the intense winds and rough seas that prevent leisure and rest, intense undertows in which the water advances over the beach and the city interfere in the flow of public roads and can invade homes and businesses, temporarily altering the dynamics of everyday life.
Why is the sea rougher at night?
The sea gets rougher at night due to a phenomenon known as tide, which, in turn, is caused by the gravity of the Moon. The gravitational field of Earth's natural satellite is responsible for the oscillation in sea level, causing it to increase in the areas over which the Moon is. Tides are also characterized by the agitation of sea waters and the occurrence of waves, which even serve to generate electricity. When the planet is aligned with the Moon, the tides are even more intense.
Then, during the night, sea level tends to rise and the waters become rougher by the influence of the Moon's gravitational field. During the day, the relative position of the Moon changes and the satellite has less influence over the area, and the sea returns to a state of apparent calm, disregarding other external factors.
Image credits
[1]Arthur Villato
Sources
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ESSAY. Did you know? Why do high and low tides occur? Earth, [n.d.]. Available in: https://www.terra.com.br/byte/ciencia/voce-sabia-por-que-ocorrem-as-mares-alta-e-baixa, 1d8b24618a8a4c32995a596c04b3649771qr9w9k.html.
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Source: Brazil School - https://brasilescola.uol.com.br/geografia/ressaca-maritima.htm
