2,436 articles
Severnaya Zemlya (Северная Земля)
Severnaya Zemlya (Северная Земля, "Northern Land"), originally Nicholas II Land, is a Russian Arctic archipelago of about 36,800 km² between the Kara and Laptev seas, discovered in 1913 and mapped by the 1930–32 Ushakov–Urvantsev expedition.
Seymour Narrows
Seymour Narrows, the narrowest part of Discovery Passage, British Columbia, is a tidal bottleneck with currents up to 16 knots. Its underwater hazard Ripple Rock, which sank over 100 ships, was destroyed in the 1958 Ripple Rock explosion.
Shabogamo Lake
Shabogamo Lake, western Labrador, Newfoundland and Labrador, Canada; also spelled Shabogama (Algonquian, "water penetrates"). A 376 km² lake near Labrador City, downstream of Wabush Lake mine tailings, namesake of the Shabogamo Gabbro (~1375 Ma).
Shadegan Ponds (تالاب شادگان)
Shadegan Ponds (تالاب شادگان), or Shadegan Wetland, is Iran's largest Ramsar site (400,000 ha, Khuzestan, designated 1975), a Jarahi delta marsh and tidal mudflat complex vital for Marbled Teal, now severely shrunk by dams, pollution, and drainage.
Shark Bay
Shark Bay (Gathaagudu), Western Australia: a 2.2-million-hectare World Heritage embayment with the world's largest seagrass beds, about 11,000 dugongs, Hamelin Pool stromatolites, and Dirk Hartog's 1616 landing site.
Shatsky Rise
Shatsky Rise is a large oceanic plateau and large igneous province ~1,300 km east of Japan, formed at a spreading ridge triple junction in the Late Jurassic–Early Cretaceous; Tamu, Ori, and Shirshov massifs; plume–ridge interaction origin.
Shatt al-Arab (شط العرب)
Shatt al-Arab (شط العرب), also Arvand Rud, is the Tigris-Euphrates confluence river flowing to the Persian Gulf along the Iran-Iraq border, defined by the 1975 Algiers thalweg boundary, the 1980-88 war, and severe Basra salinity intrusion.
Shebelle (river, Somalia)
Shebelle River (Webi Shabeelle), longest river in eastern Ethiopia at over 1,000 km, rises in the Ethiopian highlands, flows into Somalia toward the Arabian Sea, over 90% of discharge from highland runoff, often dries in lower reaches.
Shelf edge
Shelf edge (shelf break): the line of marked gradient increase at the seaward margin of a continental or island shelf, conventionally at 183-200 m depth but ranging 50-550 m, controlled by tectonics, sediment supply, and sea level.
Shelf valley
A shelf valley is a valley incised into the continental shelf floor, cut by rivers when sea level fell, often extending an existing river and feeding submarine canyons.
Shelikhov Gulf
Shelikhov Gulf (залив Шелихова), largest gulf of the Sea of Okhotsk between mainland Asia and Kamchatka; 650 km long, up to 350 m deep, tides to 12.9 m, ice-covered December to May, named for explorer Grigory Shelikhov.
Shenandoah River
The Shenandoah River is a Potomac tributary formed at Front Royal, Virginia, by the North and South Forks, flowing 57 miles to Harpers Ferry; a top eastern smallmouth bass river with fish kills and harmful algal blooms.
Sherman Basin
Sherman Basin names two features: a bay in the Kitikmeot Sea, Nunavut, Canada (67°49'N 97°35'W), an ecologically rich Arctic bay studied by DFO and Kristina Brown, and a small Paleozoic foreland basin in northeast Texas.
Shigir Idol
Shigir Idol (Шигирский идол): an Early Mesolithic larch sculpture from a Urals peat bog, found 1894, dated c. 11,500 years old, the world's oldest known monumental wooden sculpture, displayed in Yekaterinburg.
Shikoku Basin
Shikoku Basin (四国海盆), an inactive back-arc basin on the northern Philippine Sea Plate south of southwest Japan; formed by seafloor spreading about 30–15 Ma, bounded by the Kyushu-Palau Ridge, and now subducting at the Nankai Trough.
Shilka (Amur)
Shilka (Amur) is FEOW freshwater ecoregion 619, a Palearctic temperate upland rivers ecoregion covering the Shilka River drainage in Russia and Mongolia, with one endemic fish.
Shivanasamudra Falls (ಶಿವನಸಮುದ್ರ ಜಲಪಾತ)
Shivanasamudra Falls (ಶಿವನಸಮುದ್ರ ಜಲಪಾತ), twin Kaveri waterfalls Gaganachukki (90 m) and Bharachukki (69 m) in Mandya-Chamarajanagar, Karnataka, site of Asia's first major hydroelectric station, commissioned 1902 with a 147 km line to Kolar Gold Fields.
Shoebill
Shoebill (Balaeniceps rex), also called whale-headed stork, a Vulnerable solitary African swamp bird, sole member of Balaenicipitidae, related to pelicans and hamerkop, hunting lungfish with a foot-long bill.
Shoshone Falls
Shoshone Falls, the Niagara of the West, is a 212-foot waterfall on the Snake River near Twin Falls, Idaho, carved by the Bonneville Flood, seasonally reduced by irrigation diversions, and home to a 1907 hydroelectric plant.
Shtokman field (Штокмановское месторождение)
Shtokman field (Штокмановское месторождение), a giant Barents Sea gas condensate field 600 km from Murmansk with 3.9 tcm of gas; Gazprom-Total-Statoil consortium suspended development in 2012 over $30 billion costs and US shale gas.
Siberia Abyssal Plain
Siberia Abyssal Plain, also called Fletcher Abyssal Plain or Makarov Basin, is a GEBCO-named deep Arctic Ocean seafloor plain in the Makarov Basin off East Siberia, about 3,940 m deep, joined to the Wrangel Plain by the Arlis Gap.
Siberian Shelf
The Siberian Shelf comprises the Kara, Laptev, and East Siberian seas, the world's widest, shallowest continental shelf (20–30 m average depth), dominated by Siberian river freshwater, relic subsea permafrost, and rapid sea-ice retreat.
Sibuyan Sea
The Sibuyan Sea is an inland sea of the central Philippine archipelago between Tablas, Panay, Masbate, and Luzon's Bicol region, linking the Pacific to the South China and Sulu Seas.
Sierra Madre del Sur (protected area)
Sierra Madre del Sur, FEOW freshwater ecoregion 170 (not a formal protected area), Neotropic coastal rivers of Guerrero and Oaxaca, Mexico, draining Pacific slopes of the Sierra Madre del Sur; major rivers Petatlán, Papagayo, Verde, Colotepec.
Siletiteniz
Siletiteniz (Seletyteniz, Силетытениз) is a shallow endorheic salt lake in North Kazakhstan Region, Kazakhstan, about 750–780 km² in area, 2 m mean depth, fed mainly by snowmelt from the Silety River.
Siling
Siling (色林错, Siling Co/Selin Co) is Tibet's largest lake, a brackish endorheic lake at ~4,530 m on the central Tibetan Plateau; it expanded ~40% since the 1970s and overflowed into Bam Co in September 2023.
Siljan
Siljan, lake in Dalarna, Sweden, seventh largest by area (293 km², max depth 134 m), largest lake in the Siljan Ring, Europe's largest meteorite impact structure, regulated since the 1920s, outlet to Dalälven at Leksand.
Simcoe
Lake Simcoe, southern Ontario's largest lake outside the Great Lakes (722 km², 42 m max depth), a Trent-Severn Waterway lake with a major ice fishery, Protection Plan since 2009, and invasive-species and chloride stressors.
Singapore Strait
Singapore Strait (Selat Singapura), eastern continuation of the Strait of Malacca south of Singapore; shortest Indian Ocean–Pacific shipping route, over 300 vessels daily, narrowest point 530 m, managed by Indonesia, Malaysia, and Singapore under STRAITREP.
Sir Creek
Sir Creek: 96-km tidal estuary in the Rann of Kutch disputed between India and Pakistan; Pakistan claims the eastern bank under the 1914 Resolution Maps, India claims mid-channel (thalweg), blocking maritime boundary delimitation in the Arabian Sea.