Mascaret

The mascaret is a phenomenon of abrupt heightening of the water of a Fleuve or a Estuaire caused by the rising tidal wave at the time of the spring tides. It occurs in the mouth and the lower course of some Fleuve S when their current is opposed by the flow of the rising Marée. The most spectacular mascarets are observed with the mouths of the Severn, in England, and of the the Amazon, with the Brésil.

Explanations

This phenomenon is characterized by a wave, more or less high, which goes up the course of the river and whose power varies according to the height of the Marée, of the flow of the river at this time and the Topographie (depth and width of the bed, sand banks, meanders, declivity etc). The installation of the river can make it attenuate or disappear as for the the Seine. It is a wave, beachcomber or not, going up the river, being generally accentuated when its bed is tightened.

Physically, the mascaret corresponds to the propagation of a projection along the course of a river or a channel. One can observe this same fixed and circular projection in the sink when the Robinet runs. This projection ends up breaking up into several waves because the waves move more quickly when they are long. It generally finishes in Amont in a soliton. This same equivalent phenomenon exists in optics: the Soliton.

France

In the Gironde, it is particularly visible on:

the the Dordogne, a little front Libourne, with Vayres,
the the Garonne.

Into low the Seine powerful a mascaret until the Années 1960 occurred. The mascaret with Caudebec-in-Caux was considered, but it disappeared following the alterations made to the river (Dragage).

In Basse-Normandie and Brittany, this phenomenon is visible in the bay Mount-Saint-Michel at the time of coefficient higher than 90; dimensioned Norman, the observation of the phenomenon is guaranteed to the point of Grouin, and of course since the Mount-Saint-Michel; and of less visible width but, posted all the same on the bridge of Pontaubault when it goes up in the Sélune.

Use and dangerosity

It makes it possible surfers to be devoted to contests of distance from course on the wave. The mascaret can be a dangerous phenomenon for navigation and particularly for the Péniche S and the vat S which are not conceived to face the waves, as for the people which are held on the banks, sometimes to contemplate it the days of spring tides.

Literature

A phenomenon of mascaret is in the middle of the intrigue of the novel of Maurice Leblanc putting in scene Arsène Lupin, the bar goes there .

Anecdotes

It is said that it is a mascaret which carried Léopoldine, the girl of Victor Hugo, for which, inconsolable, he wrote the poem “Demain, at dawn…” ( Contemplations ). However, the town of Villequier near to Caudebec-in-Caux has in the house Vacquerie (name of the son-in-law of Victor Hugo, married to Léopoldine) transform in museum Victor Hugo, the newspaper cutting reporting the drama of the shipwreck on September 4th, 1843 on the Seine with the place known as " back of âne" and making state of a strong sudden and unforeseen strong gale, and not the mascaret, which would have laid down the boat charged with 4 people and whose badly subjugated ballast added at the last time would have contributed to the shipwreck.

External bonds

the mascaret, you know?
of a mascaret on Quiantang in China in September 2000 having made to several victims
surfers on the mascaret of the Dordogne with St Forgiveness of Vayrès (the Gironde - France)

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