"Alsek Peak" 02-35
Alsek Peak, a 2,716 m mountain summit in the Saint Elias Mountains of Yukon, Canada, in the glaciated Alsek River drainage that flows west to the Pacific.
"Buckwell Peak" 25-45
Buckwell Peak, also listed with Mount Bigger naming ambiguity, is a 2721 m ultra-prominent (1961 m) summit in the Eastern Alsek Ranges, Saint Elias Mountains, and the highest point of the Alsek Ranges on the BC/Alaska border.
"Detour Peak" 50-35
Detour Peak is a 2550 m (8366 ft) ultra-prominent summit, 1906 m prominence, in the Saint Elias Mountains' Alsek Ranges, Stikine Region, British Columbia, near Detour Creek and the Tatshenshini River.
"Kwatna Peak" 04-58
Kwatna Peak (04-58) is a 2,280 m ultra-prominence summit, prominence 2,215 m, in the Northern Pacific Ranges of British Columbia's Coast Mountains, named for the Kwatna River drainage on Burke Channel.
1974 Lima earthquake
The 1974 Lima earthquake was a magnitude 7.7 offshore earthquake that struck Lima and Callao, Peru, on 3 October 1974, killing 252 people and generating tsunami waves over 5 meters high.
2026 Dhekunu Kandu cave diving incident
The 2026 Dhekunu Kandu cave diving incident was a diving accident off Thinadhoo, Maldives, on May 14, 2026, killing five Italian divers and a military rescuer.
Abaco Islands
The Abaco Islands are a 120-mile chain in the northern Bahamas centered on Great Abaco (1,214 km2), known for Caribbean pine forests, loyalist settlement, the ground-nesting Bahama Parrot, and Hurricane Dorian's 2019 Category 5 landfall.
Abakan Range
Abakan Range (Абаканский хребет), a mountain range in southern Siberia, mainly in Khakassia; a southern spur of the Kuznetsk Alatau linking it to the Altai, about 300 km long, highest point 1984 m, watershed of the Yenisei and Ob basins.
Abercrombie Mtn.
Abercrombie Mountain: 7,310-ft (2,228 m) Selkirk Mountains summit in Colville National Forest, northeastern Washington; 5,174-ft prominence, #53 lower-48 ultra peak, highest point in Stevens County, named for Army officer William Abercrombie.
Abimes de la Fage Formation
Abîmes de la Fage (Gouffre de La Fage): Middle Pleistocene fossil-filled swallow holes at Noailles, Corrèze, France, in Bajocian limestone of the Causse de Martel; MIS 8 (242–301 ka) mammal and bird fauna, excavated 1963–1968, now a show cave and Natura 2000 bat site.
Ablation zone
The ablation zone is the lower part of a glacier where melting and calving remove more ice than snowfall adds, separated from the accumulation zone by the equilibrium line.
Abu Musa (ابوموسی)
Abu Musa (ابوموسی) is a disputed Persian Gulf island near the Strait of Hormuz, claimed by Iran and Sharjah (UAE). Partitioned by a 1971 memorandum, fully controlled by Iran since 1992; hosts an Iranian garrison and the Mubarak oil field.
Academy of Sciences Ice Cap
Academy of Sciences Ice Cap, on Komsomolets Island, Severnaya Zemlya, Russia; largest ice cap in the Russian Arctic at 5,575 km², 749 m summit, 2,184 km³ volume, 42% marine margin, near-zero climatic mass balance.
Acamarachi
Acamarachi (Cerro Pili) is a steep andesitic-dacitic stratovolcano in Antofagasta, northern Chile, about 80 km SE of San Pedro de Atacama; 6,023–6,046 m, no known Holocene eruptions, unmonitored, 87th in Chile's volcanic risk ranking.
Acarai Mountains
Acarai Mountains (Serra do Acaraí, Akarai Mountains), a low forested range on the Guyana–Brazil border, one of Guyana's four principal ranges, highest point 1,009 m, source of the Essequibo River and part of the Guiana Shield.
Acatenango
Acatenango is a 3,976 m stratovolcano in Guatemala, 15 km southwest of Antigua and 3 km north of Fuego. Third highest in the country; last erupted in 1972; famous hiking viewpoint over Fuego.
Achill Island
Achill Island, County Mayo: Ireland's largest offshore island, joined to the mainland by the 1888 Achill Sound swing bridge. About 3,000 residents, Croaghaun's 668 m cliffs, five Blue Flag beaches, Gaeltacht status, and active coastal research.
Aconcagua
Aconcagua, in Mendoza Province, Argentina, is the highest mountain in the Americas and outside Asia at about 6,962 m. First climbed by Matthias Zurbriggen in 1897; key routes are the Normal Route and the 360° route.
Adak Island
Adak Island, largest of the central Aleutian Islands, Alaska (289 sq mi, Mt. Moffett 3,875 ft). WWII Army base from 1942, Cold War Navy anti-submarine base until NAF Adak closed March 31, 1997; now a small Aleut community.
Adam's Bridge
Adam's Bridge, also known as Rama's Bridge or Rama Setu, is a chain of limestone shoals and sandbanks connecting Rameswaram Island in India with Mannar Island in Sri Lanka.
Adam's Peak
Adam's Peak (Sri Pada), a 2,243 m Sri Lankan mountain, bears a summit footprint venerated by Buddhists, Hindus, Muslims, and Christians; pilgrimage season runs December to May with about two million annual pilgrims.
Adamawa Plateau
The Adamawa Plateau is a highland area centered in north-central Cameroon at about 1,100 meters elevation, marking the climatic divide between humid Central Africa and the drier Sahel.
Adams (volcano)
Mount Adams (Pahto), Washington's largest active volcano, a 3,742 m andesitic stratovolcano in the Cascades; ~300 km³ erupted over 520,000 years; last erupted roughly 1,000-7,600 years ago; main hazard is lahars.
Adelaide Island (landform)
Adelaide Island, an ice-covered island off the west Antarctic Peninsula at about 67°15'S, 68°30'W, was named by John Biscoe in 1832 after Queen Adelaide and hosts the UK's Rothera Research Station.
Adirondack High Peaks
The Adirondack High Peaks are 46 Adirondack mountains, originally those believed over 4,000 feet, topped by Mount Marcy (5,344 ft); basis of the Adirondack 46er hiking challenge and the 275,460-acre High Peaks Wilderness.
Adirondack Mountains
Adirondack Mountains: a dome-shaped range in northeastern New York within six-million-acre Adirondack Park; Grenville Province rocks over a billion years old, distinct from the Appalachians; highest peak Mount Marcy at 5,344 feet.
Admiralty Island
Admiralty Island (Tlingit Kootznoowoo, "fortress of the bears") is a 1,664-square-mile island in Alaska's Tongass National Forest, second largest in the Alexander Archipelago, mostly national monument and wilderness, with about 1,500 brown bears, the world's densest bald eagle nests, and the village of Angoon.
Admiralty Mountains
Admiralty Mountains, also Admiralty Range, a mountain group in northeastern Victoria Land, Antarctica, on the Ross Sea coast. Discovered by James Clark Ross (1839-41); highest peak Mount Minto, 4,165 m.
Adrar Bou Nasser
Adrar Bou Nasser (Jbel Bou Naceur, جبل بوناصر) is a 3,340 m peak in Morocco's Middle Atlas, the highest summit of the South Middle Atlas Fault Zone, with 1,642 m prominence and Quaternary rock glaciers.
Aegean Islands
Aegean Islands: Greek archipelago in the Aegean Sea between mainland Greece, Asia Minor, and Crete; largest island complex in Europe, including Cyclades and Dodecanese, volcanic arc with Santorini, tourism-driven economy.