3,546 articles
Starbuck Island
Starbuck Island, also known as Volunteer Island, is an uninhabited coral atoll in the southern Line Islands of Kiribati, once mined for guano and home to millions of sooty terns.
Stavropol Upland
Stavropol Upland (Ставропольская возвышенность), upland in central Subcaucasia, Stavropol Krai, Russia; elevations 300–600 m, maximum 831 m at Mount Stryzhament; Black Sea–Caspian watershed dividing Ciscaucasia into western and eastern parts.
Steacie Ice Cap
Steacie Ice Cap, a 5,100 km2 ice cap on southwestern Axel Heiberg Island, Nunavut, Canada, one of the island's two major ice caps with Müller Ice Cap, drained by the advancing Good Friday Glacier.
Steele Island
Steele Island, an ice rise on the Larsen Ice Front off the Black Coast of Palmer Land, British Antarctic Territory, at 71°00'S 60°43'W; surveyed by USAS in 1940 and named for Clarence E. Steele, East Base tractor driver.
Steens Mountain
Steens Mountain is a 9,733-foot fault-block mountain in southeastern Oregon, the state's highest point east of the Cascades, with glacial gorges, the 170,200-acre Steens Mountain Wilderness, and the 2000 CMPA.
Stefansson Island
Stefansson Island is an uninhabited island in Nunavut's Canadian Arctic Archipelago, northeast of Victoria Island; about 4,463 km², flat lowland, named in 1952 for explorer Vilhjalmur Stefansson.
Steierdorf Formation
Steierdorf Formation: Early Jurassic (Hettangian–Sinemurian) continental coal-bearing formation in the Reșița Basin, South Carpathians, Romania, at Anina; famed for over 120 fossil plant taxa, tetrapod tracks, and 1792–2006 coal mining.
Steller
Mount Steller is a 2,272 m glaciated Holocene-active stratovolcano in Katmai National Park, Alaska, between Denison and Kukak volcanoes; unmonitored, no historical eruptions, named 1928 for naturalist Georg Wilhelm Steller.
Stelvio Pass
Stelvio Pass (Passo dello Stelvio, Stilfser Joch), 2,757–2,758 m alpine pass between Lombardy and South Tyrol, Italy. Highest paved pass in Italy, second in the Alps; SS38 road built 1820–1825 by Carlo Donegani, 48 hairpins on the Trafoi side, Giro d'Italia classic.
Stepovak Bay Group
Stepovak Bay Group: volcanic field of four Quaternary vents (Stepovak Bay 1-4) on the western Alaska Peninsula, SW of Kupreanof volcano; tholeiitic andesite, Holocene flows, GVP number 312055.
Steppe
A steppe is a level, treeless grassland plain, the name coming from the Russian stepi; the vast Eurasian Steppe stretches from Eastern Europe to Mongolia.
Stewart Island / Rakiura
Stewart Island (Rakiura), New Zealand's third-largest island, lies 30 km south of Bluff across Foveaux Strait, covers about 1,680 km², is 85% Rakiura National Park, and had 500 residents in 2025.
Stone Forest
Stone Forest (石林, Shílín) is a UNESCO World Heritage site in Yunnan, China, featuring towering karst pillars formed from shallow marine carbonate deposits over 270 million years ago.
Stony desert
Stony desert, also called reg, serir, gobi, or gibber terrain, is a gravel-armored desert plain formed by deflation and dust accretion; sand covers only about 20 percent of Earth's deserts, while stony and rocky surfaces dominate.
Store Koldewey
Store Koldewey ("Big Koldewey"), also Koldewey Island, is an uninhabited 90 km-long island off northeastern Greenland, largest of the Koldewey Islands, separating Dove Bugt from the Greenland Sea; named after Karl Koldewey of the 1869–70 German expedition.
Straumøya
Straumøya (also Straumoya) is a 29.7 km² island in Bodø Municipality, Nordland, Norway, in Saltfjorden south of Bodø, bounded by Sundstraumen and Saltstraumen, crossed by Fylkesvei 17; distinct from namesake islands in Frøya and Smøla.
Strzelecki Desert
Strzelecki Desert: arid linear-dune desert in northeastern South Australia extending into Queensland and NSW, 80,250 km², named via Strzelecki Creek after explorer Paul Edmond de Strzelecki, drained by Cooper Creek, with Cooper Basin petroleum fields.
Subglacial channel
A subglacial channel is a conduit carrying meltwater at a glacier bed, melted upward into the ice (an R-channel) or eroded downward into bedrock (a Nye channel).
Subglacial drainage
Subglacial drainage is the movement of meltwater at the base of a glacier or ice sheet through films, cavities, and channels, governing basal sliding, erosion, and outburst floods.
Subterranean river
Subterranean (underground) rivers flow through karst cave conduits dissolved in soluble rock, distinct from aquifers; mapped by dye tracing, modeled with conduit-matrix tools, and tapped for water supply.
Sudest Island
Sudest Island, also Tagula or Vanatinai, is the largest island of the Louisiade Archipelago, Milne Bay Province, Papua New Guinea; home of the Sudest (Tagula) language and site of the 1888 Australian gold rush.
Sudetes
The Sudetes are a Central European mountain range, about 300 km long, across Czechia, Poland, and Germany; a rejuvenated Variscan orogen whose highest range, the Krkonoše, hosts the world's first transboundary UNESCO biosphere reserve.
Sugarloaf Island
Sugarloaf Island: name of several small islands, notably a seabird-rich islet off Clarence Island, South Shetland Islands (61°11'S 54°00'W), and a monitored living-shoreline island at Morehead City, North Carolina.
Sugarloaf Mountain
Sugarloaf Mountain (Pão de Açúcar), a 396 m gneiss monolith at the entrance of Guanabara Bay, Rio de Janeiro; a UNESCO World Heritage site reached by Brazil's first cable car (1912), with about 2 million visitors yearly.
Sulaiman Mountains
Sulaiman Mountains (Koh-e-Sulaiman), north-south range in western Pakistan and Zabul, Afghanistan; highest point Takht-e-Sulaiman 3,487 m; fold-thrust belt of the India-Eurasia collision with unique Chilghoza pine forests.
Sulamutag Feng
Sulamutag Feng (苏拉木塔格峰) is an unclimbed 6,245 m mountain in the Altyn-Tagh range of northwestern China, in Xinjiang near the Qinghai border, described by some sources as the range's highest summit.
Sulawesi
Sulawesi (Celebes), large Indonesian island in Wallacea west of the Wallace Line, famed for endemic wildlife, million-year archaeology, the Gowa sultanate, the 2018 Palu earthquake, and its dominant nickel industry.
Sumaco
Sumaco, isolated stratovolcano in Ecuador's Sub-Andean Amazon (Napo and Orellana provinces), 105 km east of Quito; alkaline back-arc volcano, potentially active, last confirmed eruption 1895, core of Sumaco Biosphere Reserve.
Šumadija (Шумадија)
Šumadija (Шумадија), central Serbia's historical heartland region between the Sava-Danube, Morava, and Kolubara rivers; forest-derived name, hilly relief up to Rudnik 1,132 m, uprisings of 1804–1815, Kragujevac as main center, and a noted wine region around Topola and Oplenac.
Sumatra
Sumatra (Sumatera), westernmost of Indonesia's Great Sunda Islands: 178,338 sq mi, about 46 million people, oil, gas, palm oil and coal exports, Sunda megathrust earthquakes including the 2004 M9.1, and the endangered Tropical Rainforest Heritage.