2,436 articles
Grande Sebkha d'Oran
Grande Sebkha d'Oran (Great Sebkha of Oran) is a 56,870-ha closed saline depression south of Oran, Algeria; Ramsar site 1055 since 2001, an IBA for greater flamingo, fed by a 1,890 km² endorheic basin with brine near 180 g/L chlorides.
Grandidier Channel
Grandidier Channel, a channel off the Graham Coast of the Antarctic Peninsula between the Biscoe Islands and the mainland, charted by Charcot's 1903-05 French expedition and named for Alfred Grandidier.
Grauballe Man
Grauballe Man (Grauballemanden) is a Danish Iron Age bog body found in Nebelgaard Bog in 1952, dated around 390 BC, executed by throat-cutting, and displayed at Moesgaard Museum as the world's best-preserved bog body.
Great Australian Bight
The Great Australian Bight is a large open bay on Australia's southern coast, spanning Western Australia and South Australia. Known for its cool-water carbonate ramp, southern right whale calving at Head of Bight, high endemism, and the 45,822 km² Great Australian Bight Marine Park.
Great Bear Lake
Great Bear Lake (Sahtu), Northwest Territories: largest lake entirely within Canada, 31,153 km2, 446 m deep, Arctic Circle, five arms, Délı̨nę Got'ine, UNESCO biosphere reserve, record-low water levels 2023-2025.
Great Belt
The Great Belt (Storebælt) is the widest Danish strait, separating Zealand and Funen and connecting the Kattegat with the Baltic Sea, crossed by a fixed road and rail link.
Great Bitter Lake
Great Bitter Lake (al-Buḥayrah al-Murra al-Kubrā) is a 250 km² saltwater lake at the midpoint of Egypt's Suez Canal, formed from a dry salt flat when the canal opened in 1869, serving as the convoy crossing zone and formerly a salinity barrier to Red Sea species.
Great Blue Hole
The Great Blue Hole is a 320 m wide, 125 m deep flooded karst sinkhole in Lighthouse Reef atoll, Belize, formed during glacial low sea level, anoxic below 90 m, a UNESCO-protected diving site and annually layered climate archive.
Great Dismal Swamp
The Great Dismal Swamp is a 113,000-acre forested peatland refuge in southeastern Virginia and northeastern North Carolina, the largest remnant of a once million-acre wetland, drained by 150 miles of ditches, home to Lake Drummond and historic maroon communities, now being rewetted through 64 water-control structures.
Great Flood of 1862
The Great Flood of 1862 (winter 1861–1862) was California's most severe recorded flood, driven by successive atmospheric rivers that dropped up to 37 inches of rain, drowned Sacramento, killed thousands, and destroyed a third of taxable property.
Great Flood of 1993
The Great Flood of 1993, or Flood of 93, was a flood of the Mississippi and Missouri Rivers across nine US states and the costliest in US history.
Great Lakes
The Great Lakes (Superior, Michigan, Huron, Erie, Ontario) are North America's five connected freshwater lakes, the largest fresh surface water system on earth, holding about one-fifth of the world's fresh surface water and supplying over 40 million people.
Great Lakes region
The Great Lakes region is the North American area around Lakes Superior, Michigan, Huron, Erie, and Ontario and their basin, spanning eight U.S. states and Ontario, holding about 21% of the world's surface fresh water and a $6 trillion economy.
Great Pacific garbage patch
The Great Pacific garbage patch (Pacific trash vortex) is a North Pacific accumulation of floating plastic between Hawaii and California, held by the North Pacific Subtropical Gyre; estimated at 1.8 trillion pieces, mostly microplastics by count and fishing nets by mass.
Great Ruaha
Great Ruaha River, in southwestern Tanzania, a 750 km tributary of the Rufiji feeding the Mtera and Kidatu dams, which generate roughly half of Tanzania's electricity; perennial until it first dried in December 1993 due to upstream Usangu rice irrigation.
Great Salt Lake
Great Salt Lake: hypersaline closed-basin lake in northern Utah, remnant of Lake Bonneville; largest saline lake in the Western Hemisphere, eighth largest worldwide; shrinking since 2021 record lows.
Great Sandy Strait
Great Sandy Strait: 70 km double-ended sand passage estuary in south-eastern Queensland between the mainland and K'gari (Fraser Island); Ramsar site since 14 June 1999, 93,160 ha, famed for migratory shorebirds, dugongs, and turtles.
Great Slave Lake
Great Slave Lake: large deep lake in the Northwest Territories, Canada; fifth largest in North America at 27,195 km2, 625 m deep in Christie Bay, outlet of the Mackenzie River, fur-trade hub since 1786.
Greenhouse gas emissions from wetlands
Greenhouse gas emissions from wetlands: methane, CO2, and N2O fluxes from waterlogged soils. Wetlands emit ~159 Tg CH4/yr, the largest natural methane source, controlled by water table, temperature, and substrates.
Greenland Sea
The Greenland Sea is a marginal sea of the Arctic Ocean between eastern Greenland and the Norwegian Sea, bounded by the Fram Strait and the Denmark Strait.
Grijalva - Usumacinta
Grijalva-Usumacinta: Mexico's largest river system, joining in Tabasco; drains ~112,550 km², ~30% of national runoff, delta seventh worldwide by discharge; Usumacinta undammed in Mexico, Grijalva dammed since 1964; FEOW freshwater ecoregion 173.
Guadiana
Guadiana, Iberian river rising in Spain and forming the Spain-Portugal border to the Atlantic; heavily dammed (39 reservoirs, Alqueva, Europe's largest artificial lake) with a depleted upper aquifer and a shared transboundary estuary.
Guaíra Falls
Guaíra Falls (Sete Quedas, Saltos del Guairá) was a Paraná River waterfall on the Brazil–Paraguay border, 18 cataracts averaging 13,309 m³/s, submerged in October 1982 by the Itaipu Dam reservoir and later dynamited.
Guanabara Bay
Guanabara Bay (Baía de Guanabara), the 412 km² Atlantic bay of Rio de Janeiro, Brazil, entered by the Portuguese on January 1, 1502; site of France Antarctique and the 1565 founding of Rio, now a hypereutrophic estuary under long-running cleanup programs.
Guantánamo Bay
Guantánamo Bay (Bahía de Guantánamo), also called Gitmo, is a sheltered hourglass-shaped Caribbean bay in southeastern Cuba, site of a 45-square-mile U.S. naval base leased since 1903 for $4,085 a year and of post-2002 detention facilities.
Guaporé
Guaporé is a river rising on the Mato Grosso plateau in western Brazil, about 1,550 km long, forming the Brazil–Bolivia border before joining the Mamoré River.
Guapore - Itenez
Guaporé - Iténez, FEOW freshwater ecoregion 319 in Bolivia and Brazil; the Rio Guaporé (Río Iténez), a clearwater Brazilian Shield tributary of the Madeira with 25 endemic fish species including Corydoras and Phreatobius sanguijuela.
Guaymas Basin
Guaymas Basin, Gulf of California: young sedimented rift basin with two spreading troughs, basalt sill intrusions into organic-rich sediment, hydrothermal vents to 315°C, hydrothermal petroleum, and rich hydrocarbon-oxidizing microbial communities.
Guba Gusinaya
Guba Gusinaya (Губа Гусиная, "Goose Bay") is a Siberian arctic bay listed at 71°45′N 149°30′E in the Pub. 183 Northern Coast of Russia Pilot gazetteer; guba is the Pomor term for a river-mouth bay.
Gulf Coast of the United States
Gulf Coast of the United States: the Texas-to-Florida coastline on the Gulf of Mexico (Gulf of America), a low-lying wetland region marked by hurricane hazard, the seasonal hypoxic dead zone, major oil and gas and marine economies, and large Deepwater Horizon restoration programs.