Ria coast
Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Beyond NCERT
Meaning
A ria coast is a type of submergent coast with long, funnel-shaped inlets that reach far inland. It forms when the sea level rises or the land sinks, and the sea floods the lower parts of river valleys. These drowned valleys are called rias. Each ria is wide and deep at the mouth and becomes narrower and shallower inland. The ridges between the old valleys stand out as headlands. This gives the coast a jagged, deeply cut outline, often with good natural harbours.
Example
Galicia in north-western Spain has a classic ria coast. Its long sea inlets, the Rías Baixas, were once river valleys that the rising sea drowned. Southwest Ireland has a similar coast.
Don't confuse with
- Fjord: a fjord is a glacial U-shaped trough drowned by the sea in high latitudes, and it is very deep, often with a shallow lip at its mouth. A ria is a drowned river valley, and it becomes shallower inland.
Related concepts
- Emergent coast
- Submergent coast
- Longshore current
- Coastal erosion
- Sea cliff
- Wave-cut platform
- Sea cave
- Sea arch
- Sea stack