Coastal and Oceanic Landform ( 39. Ria )

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Ria of San Vicente de la Barquera in Cantabria, Spain

• A ria is a coastal inlet.

• Formed by the partial submergence of an unglaciated river valley.

• It is a drowned river valley .

• That remains open to the sea. 

• Rias have a dendritic, treelike outline.

• This pattern is inherited from the dendritic drainage pattern of the flooded river valley.

•  The drowning of river valleys along a stretch of coast.

• Rias results in an irregular and indented coastline.

• There are islands.

• They are summits of partly submerged, pre-existing hill peaks.

•  A ria coast is a coastline having several parallel.

• Rias separated by prominent ridges, extending a distance inland.

• The sea level change.

• It caused the submergence of a river valley may be either eustatic/ orisostatic.

• The result is often a very large estuary at the mouth of a relatively insignificant river.

• The Kingsbridge Estuary in Devon, England is an extreme example of a ria forming an estuary.

Ria Formosa from Quinta do Lago

Europe

• Portugal: Ria de Aveiro in Aveiro

                                Ria Formosa in Eastern Algarve

• Wales: Milford Haven in Pembrokeshire is a ria

• Spain : Andalusia  Ria of Carreras

                      Ria of Huelva

              Asturias: Ria of Avilés

              Ria of Bilbao

              Ria of Tina Mayor

              Ria of Tina Menor

Africa

• Kenya: Kilindini Harbour

Asia

• Sanriku Coast: North Japan, east coast of Honshū Island

Oceania

• Australia: The east coast of Australia features several rias around Sydney, including Georges River, Port Hacking and Sydney Harbour itself.

Georges River, in the southern suburbs of Sydney