2,436 articles
Palmer Basin
Palmer Basin, also called Palmer Deep (US ACUF), is an undersea inner-shelf basin southwest of Anvers Island, Antarctic Peninsula, up to 1400 m deep, with three sub-basins, ODP Sites 1098/1099, named for Nathaniel B. Palmer.
Palouse Falls
Palouse Falls is a 198-foot waterfall on the Palouse River in southeastern Washington, made Washington's official state waterfall in 2014 and formed by the Ice Age Missoula floods.
Paludiculture
Paludiculture is productive farming or forestry on wet or rewetted peatlands that keeps water tables high to preserve peat. Also called wet agriculture; crops include reed, cattail, Sphagnum, sago; cuts GHG emissions versus drained peatland farming.
Pamlico Sound
Pamlico Sound, North Carolina's large shallow lagoonal estuary behind the Outer Banks, largest lagoonal ecosystem in the US, 5,200 km², fed by the Tar-Pamlico and Neuse rivers, connected to the ocean by three inlets.
Panama Basin
Panama Basin: oceanic basin of the eastern equatorial Pacific, bounded by the Cocos, Carnegie, and Galapagos ridges; tectonically active, productive, hypoxic at 400 m; Gulf of Panama upwelling failed in 2025.
Panch Prayag
Panch Prayag, the five sacred confluences of the Alaknanda River in Garhwal, Uttarakhand: Vishnuprayag, Nandaprayag, Karnaprayag, Rudraprayag, and Devprayag, where the Ganga is formed.
Pangani
Pangani: river, basin, and freshwater ecoregion (FEOW 568) in northeastern Tanzania and Kenya, rising on Kilimanjaro and Meru, flowing 500 km to the Indian Ocean; noted for endemic fish, hydropower, and severe water stress.
Pangong Tso (སྤང་གོང་མཚོ)
Pangong Tso (སྤང་གོང་མཚོ), also called Pangong Lake, is a ~134 km brackish, endorheic high-altitude lake at about 4,350 m spanning Ladakh (India) and Tibet (China), bisected by the Line of Actual Control and a focal point of the India-China border dispute and 2020 standoff disengagement.
Panj
Panj (Панҷ), also Pyanj or Pyandzh: 921-km Central Asian river rising in the Pamirs, forming much of the Afghanistan-Tajikistan border and feeding the Amu Darya; subject of Tajik-Afghan hydrology cooperation, flood hazards, and glacier-fed flow.
Pantanal
The Pantanal is the world's largest tropical wetland, about 42 million acres across Bolivia, Brazil, and Paraguay, defined by an annual flood pulse, exceptional wildlife including jaguars and 10 million caimans, extensive cattle ranching, and growing fire and drought threats.
Panthalassa
Panthalassa, meaning "all water," was a vast global ocean surrounding Pangaea from the late Paleozoic into the early Mesozoic, with the Pacific Ocean as its modern remnant.
Panuco
Panuco (Pánuco), FEOW freshwater ecoregion 167, a tropical and subtropical coastal-river ecoregion on Mexico's Gulf slope centered on the Río Pánuco basin, noted for roughly 60% endemic fishes, Xiphophorus and Herichthys radiations, and endangered conservation status.
Papaloapan
Papaloapan: major river of Mexico's southern Gulf slope, draining a ~46,517 km² basin across Oaxaca, Veracruz, and Puebla; second by flow after Grijalva-Usumacinta; site of the 1947 Papaloapan Commission, Miguel Alemán and Cerro de Oro dams, and a highly endemic freshwater fish fauna.
Paraná River
Paraná River (Rio Paraná), ninth largest river by discharge, flows through a basin spanning Argentina, Brazil, Bolivia, and Paraguay; heavily dammed (Itaipú, Yacyretá, Porto Primavera), navigated since 1865, hit by 2021 drought emergencies.
Paranaíba
Paranaíba River, also Rio Paranaíba, a 1,120 km Brazilian river rising in Serra da Mata da Corda, Minas Gerais, at 1,140 m; joins the Rio Grande to form the Paraná; basin of 222,767 km² with dams Itumbiara, Emborcação, Nova Ponte; distinct from the Parnaíba River and the city of Paranaíba (MS).
Paranapanema
Paranapanema (rio Paranapanema), a left-bank tributary of the Paraná River on the São Paulo–Paraná border, Brazil; 106,554.53 km² basin, 11 hydropower dams including Chavantes and Capivara, 225 fish species.
Paratethys
Paratethys was a vast shallow epicontinental sea that covered Eurasia's southern margin from about 33 million years ago into the Pliocene, leaving the Black, Caspian, and Aral seas.
Parece Vela Basin
Parece Vela Basin, also formerly called West Mariana Basin, is an extinct back-arc basin in the Philippine Sea Plate between the Kyushu-Palau and West Mariana ridges, formed about 30-15 Ma behind the proto Izu-Bonin-Mariana arc and hosting the Godzilla Megamullion, Earth's largest known oceanic core complex.
Parnaíba (landform)
The Parnaíba (Rio Parnaíba) is a river of northeastern Brazil that flows about 1,500 km to the Atlantic, where it forms the Parnaíba Delta on the Piauí–Maranhão border.
Parnassia palustris
Parnassia palustris, marsh grass-of-Parnassus or bog star (梅花草), a circumpolar perennial herb of Celastraceae with white five-petaled flowers and nectar-mimicking staminodes, pollinated deceptively by flies, IUCN least concern.
Parry Channel
Parry Channel is the deep east-west waterway of the Canadian Arctic Archipelago, the northern Northwest Passage route through M'Clure Strait, Viscount Melville Sound, Barrow Strait, and Lancaster Sound, named for explorer William Edward Parry.
Patapsco River
The Patapsco River is a major Maryland river that flows generally southeast into the Chesapeake Bay. Its valley is known as the cradle of the state's Industrial Revolution.
Patos Lagoon
Patos Lagoon (Lagoa dos Patos), Brazil's largest coastal lagoon at about 10,360 km2 in Rio Grande do Sul, is the world's largest choked lagoon, connected to the Atlantic by a single inlet at Rio Grande and linked to Mirim Lagoon by the São Gonçalo Channel.
Payne
Payne: chiefly a northern Canadian toponym. Payne Lake (Lac Payne, Inuit Tasirruaq), 513 km2 Quebec lake draining via the Arnaud River to Payne Bay, named 1945 for meteorologist Frank F. Payne; also lakes in Alberta, Ontario, and the US.
Peace River
The Peace River in western Canada flows from the Rocky Mountains in British Columbia through Alberta to the Peace-Athabasca Delta. It is named for a Beaver-Cree peace settlement and hosts three hydroelectric dams including Site C (1,100 MW).
Pearl (landform)
Pearl (landform): chiefly the Pearl River of Mississippi and Louisiana, a 400+ mile Gulf-draining river named for 1698 pearl finds, and China's Pearl River (Zhu Jiang), formed by the West, North, and East Rivers.
Pearl Harbor
Pearl Harbor (Pu'uloa, Wai Momi) is a sheltered estuary on O'ahu, Hawai'i, home to Joint Base Pearl Harbor-Hickam; developed as a US naval base from 1902 and attacked by Japan on December 7, 1941.
Peat swamp forest
Peat swamp forest: tropical forest on waterlogged peat, best developed in Southeast Asia (Borneo, Sumatra, Peninsular Malaysia). Stores ~105 GtC in tropical peat; drained and burned for oil palm and acacia plantations, emitting ~692 Tg CO2e yearly; restored by canal blocking.
Peatland
Peatland: waterlogged wetland ecosystem (bogs, fens, mires, swamps) with surface peat from partly decomposed plants; covers ~3% of land, stores ~20% of soil carbon (238–612 Gt C), and emits ~5% of GHGs when drained.
Peatland drainage impact
Peatland drainage impact covers the environmental consequences of draining peatlands: drained peat becomes a carbon source, causing emissions, subsidence of 1 to 8 meters, and water degradation.