It’s one of those shows that only the sea has the secrets to.
It goes higher, but also goes lower than usual.
This coming and going has a name: spring tides.
And these will offer some beautiful panoramas in the coming days.
So many landscapes which will change every six hours, due to the strong tidal coefficients.
They will reach 104 as of this Sunday March 10, peaking at 117 on Tuesday March 12, according to data from the Hydrographic and Oceanographic Service of the Navy (Shom).
The spectacle should be particularly impressive in the Manche department, particularly near Saint-Malo and Mont-Saint-Michel.
The rocky islet will once again be cut off from the world for a few hours.
But how is this possible?
Originally, a tide is a variation in the amplitude of the water height on the coast.
It is mainly due to the attraction of the Moon on the Earth and, to a lesser extent, the Sun.
Depending on the position of the three stars, the amplitude of the tide will be different.
Spring tides therefore appear when there is a more or less perfect alignment between the Sun, the Earth and the Moon, and the forces of attraction add up.
In addition to the spectacle of nature, these high tides play a crucial role in the regeneration of marine habitats.
Oyster farmers can thus access their oyster beds located furthest offshore.
The next ones in April
But how to predict them?
The “largest” tides often occur during the spring (between March 20 and 22, depending on the year) and autumn (between September 21 and 23) equinoxes.
Or when the distance between the Earth-Moon couple and the Sun is the shortest.
During these periods, the tidal coefficients - which therefore make it possible to know the amplitude of the tide - can exceed the mark of 110. But no exact science here: the next ones, which will follow those of March, will only take place at from April 9, as noted by the Manche Tourist Office.
The only certainty: the places to observe them.
Saint-Malo and Mont-Saint-Michel are privileged places, where we find the largest tidal ranges in continental Europe.
This is due to the existence of the Cotentin peninsula, which acts as an obstacle and allows tidal waves to reflect and add up.
Be careful though if you have to venture out to sea, especially for those who love fishing on foot.
The water can rise very quickly.
In Mont-Saint-Michel, it is often said that the sea rises
“at the speed of a galloping horse”
.