Cotentin against the sea

Published on February 5th 2017

The Cotentin, land of Constantia (Coutances) in Normandy, is a very peculiar place. Cut in half by a nigh-uninterupted stretch of swamplands, one can distinguish its continental part, around Coutances, and its peninsula, sometimes named Corlois, near Cherbourg (Coriallo).

Peninsula, as up until some great works made in the 18th Century, these swamps would be flooded almost all year long, sometimes by the sea, sometimes by rainwater, isolating the Corlois from the continent, to which it was only permanently linked by a small stretch of land, two kilometers wide, on the western side.

Today, despite the 18e Century works, the marsh "whitens" every winter.

Cotentin (red) and marshes (green)

Whitened marshes in winter
Photo Office de Tourisme de la Baie du Cotentin

Isolated for a great part of history, the peninsula kept an insular mentality, and is still today one of the last homes to the Norman language. Hit harder by the Brittanic invasions of the fifth Century than the rest of Normandy, then colonized by Norwegian Vikings rather than Danish Vikings during the tenth Century, its outlook is quite different from the neighbouring lands.

A different outlook caused by a stretch of water only a few hundred meters wide (up to three kilometers wide between Carentan and Saint-Côme-du-Mont).

To which extend could the Cotentin peninsula become an isle? Let's melt all the ice from both poles. This would raise the sea level by up to 60 meters. The result? The stretch of sea is now 25 to 50 kilometers wide. Making the Corlois a true Channel Island.

Cotentin under 60 meters of water

This map is availbale as a license CC-BY-SA-1.0 download (you can reuse it without monetary goals by crediting the author, and you can modify it as you please which keeping this license).

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