877 articles
Gulf of Mexico
The Gulf of Mexico (also officially styled Gulf of America by some U.S. agencies) is a 218,000-square-mile semi-enclosed Atlantic basin linked to the Caribbean by the Yucatan Channel, defined by the Loop Current, major hurricanes, and half of U.S. petroleum refining capacity.
Gulf of Ob
Gulf of Ob (Обская губа), also Ob Bay, a ~850 km long estuary of the Ob River in the southern Kara Sea, Siberia; among the world's largest estuaries, receiving ~530 km³ freshwater yearly and hosting major Yamal LNG projects.
Gulf of Oman
The Gulf of Oman, or Sea of Oman, is the 560-km-long arm of the Arabian Sea linking the Persian Gulf through the Strait of Hormuz to the Indian Ocean, a deep monsoon-driven basin with seasonal coastal hypoxia and major oil shipping routes.
Gulf of Papua
Gulf of Papua: large embayment on Papua New Guinea's south coast opening to the Coral Sea, fed by the Fly, Purari, and Kikori rivers; major tide-dominated deltaic clinoform with ~385 million tonnes of annual sediment input.
Gulf of Penas
Gulf of Penas (Golfo de Penas), an open Pacific gulf in Chile's Aysén Region at about 47°22'S, 74°50'W between Cabo Tres Montes and Cabo Mogotes; named by 1557 for stormy crossings, it overlies the Golfo de Penas-Taitao basin near the Chile Triple Junction.
Gulf of Salalah
The Gulf of Salalah is a broad embayment of the Arabian Sea on the southern coast of Oman's Dhofar governorate, fronting the Salalah plain and the Port of Salalah.
Gulf of Sidra (خليج سدرة)
Gulf of Sidra (Khalīj Surt, Gulf of Sirte) is a large Mediterranean embayment on Libya's central coast, 760 km between Misurata and Benghazi, ancient Syrtis Maior, site of Libya's 1973 Line of Death claim and 1981, 1986, and 1989 US-Libya incidents.
Gulf of St. Lawrence
Gulf of St. Lawrence (Golfe du Saint-Laurent): semi-enclosed Canadian sea opening via Cabot Strait and Strait of Belle Isle; Magdalen Shallows under 80 m; ~15% of Canadian fish catch; sea ice, warming, Cartier 1534.
Gulf of Suez
Gulf of Suez: northwestern arm of the Red Sea between Egypt and Sinai, head at Suez, linked to the Mediterranean by the Suez Canal; a continental rift still widening 0.5 mm/year and an Egyptian oil province.
Gulf of Taranto
Gulf of Taranto (Golfo di Taranto), embayment of the northern Ionian Sea on southern Italy's instep, named for Taranto (ancient Taras, Spartan colony founded 706 BC); known for its Calabrian-arc tectonics, submarine geohazards, the Port of Taranto, and the Mar Grande SIN remediation site.
Gulf of Tehuantepec
Gulf of Tehuantepec (Golfo de Tehuantepec), Pacific embayment of southern Mexico between Oaxaca and Chiapas; famous for winter Tehuano gap winds through Chivela Pass that drive upwelling, 10 °C single-day SST drops, and mesoscale eddies.
Gulf of Thailand
Gulf of Thailand, formerly Gulf of Siam: semi-enclosed 320,000 km2 bay of the South China Sea bordered by Thailand, Malaysia, Cambodia, and Vietnam, up to 85 m deep, with monsoon-reversing circulation, major fisheries, and offshore oil and gas.
Gulf of Tomini
Gulf of Tomini (Teluk Tomini, Tomini Bay): deep semi-enclosed gulf between Sulawesi's northern and eastern arms, opening to the Moluku Sea; borders Gorontalo, North Sulawesi, and Central Sulawesi; contains the Togean Islands and fisheries assessed under EAFM.
Gulf of Tonkin
Gulf of Tonkin (Vịnh Bắc Bộ; 北部湾, Beibu Gulf), a shallow semi-enclosed arm of the northwestern South China Sea between Vietnam and Hainan, China; about 128,800 km², delimited by a 2000 China–Vietnam agreement in force 2004, and a major shared fishery.
Gulf of Urabá
Gulf of Urabá (Golfo de Urabá), largest estuary of the Colombian Caribbean in northwestern Antioquia/Chocó; site of Spain's 1510 mainland settlements, banana enclave, Atrato River discharge, salt-wedge sedimentation, and planned deep-water port.
Gulf St Vincent
Gulf St Vincent, South Australia's smaller gulf, an inverse estuary beside Adelaide with salinity up to 42‰, dodge tides, mangrove and seagrass habitats, prawn and snapper fisheries, and a Karenia algal bloom from March 2025.
Gulf Stream
Gulf Stream: intense warm western boundary current of the western North Atlantic, flowing from the Strait of Florida past Cape Hatteras toward Europe; average speed 6.4 km/h, first charted by Franklin in 1769–1770, a wind-driven branch of the AMOC.
Guyot
Guyot, also called tablemount: a flat-topped seamount rising at least 1,000 m above the seafloor. Term coined 1946 by Harry Hess for Arnold Guyot; formed by erosion and subsidence of volcanic islands.
Gwadar (گوادر)
Gwadar (گوادر) is a port city on Pakistan's Arabian Sea coast in Balochistan, bought from Oman in 1958; it hosts Pakistan's third deep-sea port, the CPEC flagship, operated by China's COPHCL.
Hạ Long Bay
Hạ Long Bay (Vịnh Hạ Long), northeastern Viet Nam, Gulf of Tonkin bay of limestone tower karst; UNESCO World Heritage 1994, 2000, extended 2023 with Cat Ba Archipelago; 65,650 ha, 1,133 islands, heavy tourism and conservation pressure.
Hadal zone
Hadal zone (hadalpelagic zone): the deepest ocean zone, about 6,000–11,000 m, confined to trenches and troughs, named after Hades; area near Australia's size, over 400 known trench species.
Hadley Bay
Hadley Bay (baie Hadley) is an official bay on Victoria Island, Nunavut, Canada, at 73°N 110°W, named in 1982; it gives its name to a 2013 Geological Survey of Canada tectonic assemblage map.
Halmahera Sea
Halmahera Sea: quasi-confined marginal sea in eastern Indonesia between Halmahera Island and Irian Jaya, a secondary entry portal of the Indonesian Throughflow, with ENSO-linked variability, intense internal-wave mixing, and Coral Triangle coral biodiversity.
Hamburg Bay
Hamburg Bay (German: Hamburghafen) is a bay on the northwest coast of Anvers Island, Palmer Archipelago, Antarctica, just south of Bonnier Point at about 64°30'S, 63°57'W. Discovered and named in 1874 by Dallmann's German expedition for the port of Hamburg.
Hampton Roads
Hampton Roads, Virginia: roadstead where the James, Nansemond, and Elizabeth rivers meet Chesapeake Bay; major port, US Navy hub, site of the first ironclad battle, and a region highly exposed to sea level rise.
Hanauma Bay
Hanauma Bay, on Oʻahu's southeastern coast, Hawaiʻi, is a curved bay in a breached volcanic tuff cone, the state's first Marine Life Conservation District (1967), capped at 1,400 nonresident visitors daily and known for its reef fish biomass and COVID-era recovery.
Hangzhou Bay (杭州湾)
Hangzhou Bay (杭州湾) is a funnel-shaped tidal bay on China's east coast, the Qiantang River estuary known for its tidal bore and 36 km bridge.
Hankow Reef
Hankow Reef (Yomba) is a submarine stratovolcano with summit at -5 m in the Bismarck Volcanic Arc, Papua New Guinea, between Bagabag and Crown Islands; linked to the legendary destroyed island of Yomba, with no confirmed Holocene eruptions.
Hauraki Gulf
The Hauraki Gulf (Tīkapa Moana) is a large embayment on New Zealand's northeast North Island coast, home to the 1.2-million-hectare Hauraki Gulf Marine Park (2000), over 200 islands, Bryde's whales, and the 2025 Marine Protection Act.
Hawaii hotspot
Hawaii hotspot: the volcanic center, also called the Hawaiian plume, that built the 5,800 km Hawaiian-Emperor chain over ~76 million years as the Pacific plate moved over a mantle plume, now under Mauna Loa, Kīlauea, and Lōʻihi.