gulf

A gulf is a large coastal indentation of the sea or ocean that is partially enclosed by land and opens to the sea through a mouth or channel. In common usage, gulfs are typically larger and more enclosed than bays, though there is no universal, strict boundary that separates the two terms. The designation often depends on regional naming conventions as well as historical and navigational considerations.

The term is applied to diverse geographic settings around the world. Gulfs may form through tectonic subsidence, differential land movement, and long-term coastal erosion, or through changes in sea level that expand an existing inlet. Some gulfs have substantial freshwater input from rivers and exhibit unique hydrological and ecological characteristics, while others are more saline and marine-dominated. Depth, width, and the size of the opening to the open sea vary widely among gulfs.

Notable examples include the Persian Gulf, which lies between Iran and the Arabian Peninsula; the Gulf of Mexico, bordered by the United States, Mexico, and Cuba; the Gulf of Aden, separating Yemen and Somalia; and the Gulf of Oman, linking the Arabian Sea with the Persian Gulf. Other examples include the Gulf of Alaska, the Gulf of Thailand, the Gulf of Carpentaria, and the Gulf of Saint Lawrence. Gulfs are often important for shipping, oil and gas production, fishing, and tourism, and they commonly host diverse marine ecosystems such as coral reefs, mangroves, and seagrass habitats.

See also: Bay, Inlet, Strait, Sea.