Bay

This article is about the geographical feature. For other uses, see Bay (disambiguation).

The bay at San Sebastián, Spain

The Bay of Bengal in South Asia

The bay of Baracoa, Cuba

A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, lake, or another bay. A large bay may be called a gulf, sea, sound, or bight. A cove is a type of smaller bay with a circular inlet and narrow entrance. A fjord is a particularly steep bay shaped by glacial activity.

Bays can be the estuary of a river, such as the Chesapeake Bay, an estuary of the Susquehanna River. Bays may also be nested within each other; for example, James Bay is an arm of Hudson Bay in northeastern Canada. Some large bays, such as the Bay of Bengal and the Hudson Bay, have varied marine geology.

The land surrounding a bay often reduces the strength of winds and blocks waves. Bays were significant in the history of human settlement because they provided a safe place for fishing. Later they were important in the development of sea trade as the safe anchorage they provide encouraged their selection as ports.

Formation

There are various ways from which bays can be created. The largest bays have developed as a result of plate tectonics. As the super-continent Pangaea broke up along curved and indented fault lines, the continents moved apart and the world's largest bays formed. These include the Gulf of Guinea, Gulf of Mexico and the Bay of Bengal, which is the largest bay in the world.

Another way bays form is via glacial and river erosion. A bay formed by a glacier is a fjord. Rias are created by rivers and are characterised by more gradual slopes. Currents can make waves more constant, and soft rocks speed erosion. Hard rock eroded less quickly, leaving headlands. The Gulf of California is an example of a bay created by plate tectonics as Baja California peninsula moves away from the Mexican mainland.

See also

• Bay platform
• Great capes
• Headlands and bays