mouth_of_the_watercourse purus river
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it , and with a free connection to the open ___MASK6___ . Pucallpa ( Quechua : puka allpa , " red earth ") is a city in eastern Peru located on the banks of the ___MASK33___ , a major tributary of the ___MASK76___ River . It is the capital of the Ucayali region , the Coronel Portillo Province and the Calleria District . Southern Cone is a geographic region composed of the southernmost areas of South America , south of and around the Tropic of Capricorn . Traditionally , it covers Argentina , Chile and Uruguay , bounded on the west by the ___MASK62___ , and south to the junction between the Pacific and Atlantic Oceans , which is the closest continental area of Antarctica ( 1000 km ). In terms of social and political geography , the Southern Cone comprises Argentina , Chile , Uruguay , Southern Brazil and sometimes Paraguay . The ___MASK94___ is the chief river of the largest drainage system on the North American continent . Flowing entirely in the United States ( although its drainage basin reaches into Canada ), it rises in northern Minnesota and meanders slowly southwards for to the ___MASK94___ Delta at the ___MASK68___ . With its many tributaries , the Mississippi ' s watershed drains all or parts of 31 U . S . states and 2 Canadian provinces between the Rocky and Appalachian Mountains . The Mississippi ranks as the fourth longest and fifteenth largest river in the world by discharge . The river either borders or passes through the states of Minnesota , Wisconsin , Iowa , Illinois , Missouri , Kentucky , Tennessee , Arkansas , Mississippi , and Louisiana . Purús District is the only district of the Purús Province located in the Ucayali Region in Peru . The ___MASK98___ runs through it . The ___MASK73___ is a long river running through the central region of Peru . Its Quechua name means " great river ". The word " Mantaro " may be a word originally from the Ashaninka language , who live downstream along the ___MASK28___ . The Mantaro , along with the Apurimac River , holds the distinction of being the source of the ___MASK76___ River , depending on the criteria used for definition . An ocean ( the ___MASK6___ of classical antiquity ) is a body of saline water that composes much of a planet ' s hydrosphere . On Earth , an ocean is one of the major conventional divisions of the World Ocean , which covers almost 71 % of its surface . These are , in descending order by area , the Pacific , Atlantic , Indian , Southern ( Antarctic ), and Arctic Oceans . The word " ___MASK6___ " is often used interchangeably with " ocean " in American English but , strictly speaking , a ___MASK6___ is a body of saline water ( generally a division of the world ocean ) partly or fully enclosed by land . Manaus or Manaós before 1939 or ( formerly ) Barra do ___MASK5___ , is the capital city of the state of Amazonas in the North Region of Brazil . It is situated at the confluence of the Negro and ___MASK39___ rivers . With a population of more than 2 million , it is the most populous city of both the Brazilian state of Amazonas and the Amazon rainforest . The ___MASK76___ River ( or ; Spanish and ) in South America is the largest river by discharge of water in the world , and according to some experts , the longest in length . The headwaters of the Apurímac River on Nevado Mismi had been considered for nearly a century as the ___MASK76___  s most distant source , until a 2014 study found it to be the Cordillera Rumi Cruz at the headwaters of the Mantaro River in Peru . The Mantaro and Apurímac confluence , and with other tributaries form the Ucayali River , which in turn confluences with the Marañón River upstream of Iquitos , Peru , to form what countries other than Brazil consider to be the main stem of the ___MASK76___ . Brazilians call this section the ___MASK39___ River above its confluence with the Rio Negro to form what Brazilians call the ___MASK76___ at the Meeting of Waters at Manaus , the river ' s largest city . A tributary or affluent is a stream or river that flows into a larger stream or ___MASK93___ stem ( or parent ) river or a lake . A tributary does not flow directly into a ___MASK6___ or ocean . Tributaries and the ___MASK93___ stem river drain the surrounding drainage basin of its surface water and groundwater , leading the water out into an ocean . A ___MASK6___ is a large body of salt water that is surrounded in whole or in part by land . More broadly , " the ___MASK6___ " is the interconnected system of Earth ' s salty , oceanic waters  considered as one global ocean or as several principal oceanic divisions . The ___MASK6___ moderates Earth ' s climate and has important roles in the water cycle , carbon cycle , and nitrogen cycle . Although the ___MASK6___ has been traveled and explored since prehistory , the modern scientific study of the ___MASK6___  oceanography  dates broadly to the British " Challenger " expedition of the 1870s . The ___MASK6___ is conventionally divided into up to five large oceanic sections  including the International Hydrographic Organization ' s four named oceans ( the Atlantic , Pacific , Indian , and Arctic ) and the Southern Ocean ; smaller , second - order sections , such as the Mediterranean , are known as " seas ". Peru , officially the Republic of Peru , is a country in western South America . It is bordered in the north by Ecuador and Colombia , in the east by Brazil , in the southeast by Bolivia , in the south by Chile , and in the west by the ___MASK62___ . Peru is an extremely biodiverse country with habitats ranging from the arid plains of the Pacific coastal region in the west to the peaks of the Andes mountains vertically extending from the north to the southeast of the country to the tropical Amazon Basin rainforest in the east with the Amazon river . The ___MASK76___ rainforest ( Portuguese : ' or ' ' or usually '; ), also known in English as Amazonia or the ___MASK76___ Jungle , is a moist broadleaf forest that covers most of the ___MASK76___ basin of South America . This basin encompasses , of which are covered by the rainforest . This region includes territory belonging to nine nations . The majority of the forest is contained within Brazil , with 60 % of the rainforest , followed by Peru with 13 %, Colombia with 10 %, and with minor amounts in Venezuela , Ecuador , Bolivia , Guyana , Suriname and French Guiana . States or departments in four nations contain " Amazonas " in their names . The ___MASK76___ represents over half of the planet ' s remaining rainforests , and comprises the largest and most biodiverse tract of tropical rainforest in the world , with an estimated 390 billion individual trees divided into 16 , 000 species . Iquitos , also known as Iquitos City , is the capital city of Peru ' s Maynas Province and Loreto Region . The largest metropolis in the Peruvian ___MASK76___ , east of the Andes , it is the sixth most populous city of Peru . South America is a continent located in the western hemisphere , mostly in the southern hemisphere , with a relatively small portion in the northern hemisphere . It is also considered a subcontinent of the Americas , which is the model used in nations that speak Romance languages . The reference to South America instead of other regions ( like Latin America or the Southern Cone ) has increased in the last decades due to changing geopolitical dynamics ( in particular , the rise of Brazil ). Purús Province is one of four provinces in the Ucayali Region , in the central ___MASK76___ rainforest of Peru . The Purus River runs through it . ___MASK39___ is the name often given to upper stretches of the Amazon River in Brazil from its confluence with the Rio Negro upstream to the border of Peru . The ___MASK39___ portion of the Amazon river lies entirely in the State of Amazonas , Brazil , and some portion of the state is often referred to as the " ___MASK39___ region ". The ecoregion of the ___MASK39___ river drainage basin is entirely tropical rainforest . A drainage basin or catchment basin is an extent or an area of land where all surface water from rain , melting snow , or ice converges to a single point at a lower elevation , usually the exit of the basin , where the waters join another body of water , such as a river , lake , reservoir , estuary , wetland , ___MASK6___ , or ocean . Thus if a tributary stream joins a brook that in turn joins a small river which is a tributary of a larger river , there is a series of successively larger ( and lower elevation ) drainage basins . For instance , the Missouri and Ohio rivers are within their own drainage basins and also within the drainage basin of the Mississippi River . Mismi is a mountain peak of volcanic origin located in the Ch ' ila mountain range in the Andes of Peru . A glacial stream on the Mismi was firmly identified as the most distant source of the ___MASK76___ River in 1996 ; this finding was confirmed in 2001 and again in 2007 . The waters from Mismi flow into the streams Qarwasanta and Apachita , which flow into the Apurímac River . It is a tributary of the Ucayali which later joins the Marañón to form the ___MASK76___ proper . " ___MASK93___ Stem " is 1942 instrumental by Duke Ellington and His Famous Orchestra . Although recorded in 1942 , the single would not be released until 1944 where it was Duke Ellington ' s last of four number one ' s on the Harlem Hit Parade . " ___MASK93___ Stem " also peaked at number twenty on the pop chart . The ___MASK98___ or Rio Purús is a tributary of the ___MASK76___ River in South America . Its drainage basin is 63 , 166 km2 ( 24 , 389 sq mi ) , and the mean discharge is 8 , 400 m³ / s . The river shares its name with the Alto Purús National Park as well as the Purús Province ( and its conformed Purús District ) , one of the four provinces of Peru in the Ucayali Region . The Meeting of Waters is the confluence between the dark ( blackwater ) ___MASK5___ and the pale sandy - colored ( whitewater ) Amazon River or Rio ___MASK39___ , as the upper section of the Amazon is known in Brazil upriver of this confluence . For the two rivers ' waters run side by side without mixing . It is one of the main tourist attractions of Manaus , Brazil . The same also happens near Santarém , Pará with the Amazon and Tapajós rivers . This phenomenon occurs in other regions of the world with differing characters of rivers . The ___MASK33___ arises about north of Lake Titicaca , in the Arequipa region of Peru . The ___MASK76___ River takes its name close to Nauta city ( 100 km upstream / south of Iquitos ), at the confluence of the Marañón and Ucayali rivers . The Ucayali becomes a major tributary of the ___MASK76___ River . Navigation was blocked by lengthy sections of rapids . The city of Pucallpa is located on the banks of the Ucayali . Tin is a chemical element with the symbol Sn ( for ) and atomic number 50 , is a post - transition metal in group 14 of the periodic table . It is obtained chiefly from the mineral cassiterite , which contains tin dioxide , SnO . Tin shows a chemical similarity to both of its neighbors in group 14 , germanium and lead , and has two ___MASK93___ oxidation states , + 2 and the slightly more stable + 4 . Tin is the 49th most abundant element and has , with 10 stable isotopes , the largest number of stable isotopes in the periodic table , thanks to its magic number of protons . It has two ___MASK93___ allotropes : at room temperature , the stable allotrope is  - tin , a silvery - white , malleable metal , but at low temperatures it transforms into the less dense grey  - tin , which has the diamond cubic structure . Metallic tin is not easily oxidized in air . Ucayali is an inland region in Peru . Located in the ___MASK76___ rainforest , its name is derived from the Ucayali River . The regional capital is the city of Pucallpa . A river is a natural flowing watercourse , usually freshwater , flowing towards an ocean , ___MASK6___ , lake or another river . In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water . Small rivers can be referred to using names such as stream , creek , brook , rivulet , and rill . There are no official definitions for the generic term river as applied to geographic features , although in some countries or communities a stream is defined by its size . Many names for small rivers are specific to geographic location ; examples are " run " in some parts of the United States , " burn " in Scotland and northeast England , and " beck " in northern England . Sometimes a river is defined as being larger than a creek , but not always : the language is vague . The ___MASK40___ is the principal or mainstem source of the ___MASK76___ River , arising about 160 km to the northeast of Lima , Peru , and flowing through a deeply eroded Andean valley in a northwesterly direction , along the eastern base of the Cordillera of the Andes , as far as 5 degrees 36 ' southern latitude ; from where it makes a great bend to the northeast , and cuts through the jungle Andes , until at the Pongo de Manseriche it flows into the flat ___MASK76___ basin . Although historically , the term " Marañon River " often was applied to the river all the way to the ___MASK23___ , nowadays the Marañon River is generally thought to end at the confluence with the Ucayali River , after which most cartographers label the ensuing waterway the ___MASK76___ River . Alto Purús National Park is a national park in the ___MASK76___ rainforest area of Peru , created on November 18 , 2004 . It contains some of the most rugged , treacherous , remote and unexplored territory in the ___MASK76___ . It is also home to a number of indigenous tribes , including some that have avoided contact with the outside world . Situated on the Purús River , it is the largest protected area in Peru , covering . Brazil , officially the Federative Republic of Brazil , is the largest country in both South America and Latin America . As the world ' s fifth - largest country by both area and population , it is the largest country to have Portuguese as an official language and the only one in the Americas . Bounded by the ___MASK23___ on the east , Brazil has a coastline of . It borders all other South American countries except Ecuador and Chile and covers 47 . 3 % of the continent ' s land area . Its Amazon River basin includes a vast tropical forest , home to diverse wildlife , a variety of ecological systems , and extensive natural resources spanning numerous protected habitats . This unique environmental heritage makes Brazil one of 17 megadiverse countries , and is the subject of significant global interest and debate regarding deforestation and environmental protection .