The Celtic Sea is the area of the Atlantic Ocean off the south coast of Ireland bounded to the east by Saint George's Channel; other limits include the Bristol Channel, the English Channel, and the Bay of Biscay, as well as adjacent portions of Wales, Cornwall, and Brittany.The southern and western boundaries are delimited by the continental shelf, which drops away sharply.

The Ionian Sea (Greek: Ιόνιο Πέλαγος, Iónio Pélagos [iˈonio ˈpelaɣos]; Italian: Mar Ionio [mar ˈjɔːnjo]; Albanian: Deti Jon [dɛti jɔ:n] ("our sea")) is an elongated bay of the Mediterranean Sea.It is connected to the Adriatic Sea to the north, and is bounded by Southern Italy, including Calabria, Sicily, and the Salento peninsula to the west, southern Albania (and western ...

Si stima che il mar di Marmara abbia avuto origine circa 2,5 milioni di anni fa, in seguito a movimenti della crosta terrestre.Geologicamente esso è un bacino a pull-apart formato in corrispondenza di una curva estensionale nella faglia nord anatolica. Si estende in lunghezza per circa 252 km (distanza aerea tra le città di Gallipoli e İzmit) e presenta coste alte, rocciose, con …