The Gironde Estuary and the Pertuis d’Antioche, France’s Western Coast
Sediments flow from the Dordogne and Garonne Rivers, through the Gironde Estuary (bottom right quadrant), and into the Atlantic Ocean off the western coast of France.
The rivers appear completely tan where they merge, near the city of Bordeaux (bottom right corner). This tan color takes on a progressively greener tint as the estuary widens.
Further up the coast, the waters of the Pertuis d’Antioche, a strait between the two islands Île de Ré and Île d’Oléron and the continental coast, between the cities of La Rochelle and the naval arsenal of Rochefort, are also tinged green by sediments.
The Pertuis d’Antioche is bordered by a limestone coast dating back to the Cretaceous Period, at which time is was deep under water.