mouth_of_the_watercourse south rukuru river
A ___MASK93___ is a large body of salt water that is surrounded in whole or in part by land . More broadly , " the ___MASK93___ " is the interconnected system of Earth ' s salty , oceanic waters  considered as one global ocean or as several principal oceanic divisions . The ___MASK93___ moderates Earth ' s climate and has important roles in the water cycle , carbon cycle , and nitrogen cycle . Although the ___MASK93___ has been traveled and explored since prehistory , the modern scientific study of the ___MASK93___  oceanography  dates broadly to the British " Challenger " expedition of the 1870s . The ___MASK93___ 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 ___MASK61___ ; smaller , second - order sections , such as the Mediterranean , are known as " seas ". A river is a natural flowing watercourse , usually freshwater , flowing towards an ocean , ___MASK93___ , 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 . Tanzania , officially the United Republic of Tanzania , is a country in Eastern Africa within the African Great Lakes region . Parts of the country are in Southern Africa . It is bordered by Kenya and Uganda to the north ; Rwanda , Burundi , and the Democratic Republic of the Congo to the west ; Zambia , Malawi , and Mozambique to the south ; and by the ___MASK26___ to the east . Mount Kilimanjaro , Africa ' s highest mountain , is in northeastern Tanzania . The Nyika Plateau lies in northern Malawi , with a small portion in north eastern Zambia . Most of it lies at elevations of between , the highest point being at Nganda Peak . It is roughly a diamond in shape , with a long north  south axis of about , and an east  west axis of about . It towers above ___MASK95___ ( elevation ), and the towns of Livingstonia and Chilumba . Its well - defined north - west escarpment rises about above the north - eastern extremity of the Luangwa Valley , and its similarly prominent south - east escarpment rises about above the South Rukuru River valley . It is very different in scenery from other parts of Malawi , consisting of rolling hills with little streams in broad valleys , and rough grassland with clumps of pine trees . The South Rukuru River is a river of northern Malawi . It flows through the Nyika Plateau . The Department of Irrigation in currently developing a large irrigation scheme which will cover an area of 4000 hectares in the Rumphi district on the left bank of the South Rukuru River . The project is supported by the European Union and will benefit almost 2300 farmers in the region . An ocean ( the ___MASK93___ 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 " ___MASK93___ " is often used interchangeably with " ocean " in American English but , strictly speaking , a ___MASK93___ is a body of saline water ( generally a division of the world ocean ) partly or fully enclosed by land . ___MASK95___ , also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique , is an African Great Lake and the southernmost lake in the East African Rift system , located between Malawi , Mozambique and Tanzania . It is the ninth largest lake in the world and the third largest and second deepest lake in Africa . It is home to more species of fish than any other lake , including about 1000 species of cichlids . The Mozambique portion of the lake was officially declared a reserve by the Government of Mozambique on June 10 , 2011 , while in Malawi a portion of the lake is included in ___MASK95___ National Park . ___MASK95___ is a meromictic lake , meaning that its water layers do not mix . The permanent stratification of ___MASK95___ ' s water and the oxic - anoxic boundary ( relating to oxygen in the water ) are maintained by moderately small chemical and thermal gradients . Mozambique ( or ), officially the Republic of Mozambique ( or "") is a country in Southeast Africa bordered by the ___MASK26___ to the east , Tanzania to the north , Malawi and Zambia to the northwest , Zimbabwe to the west , and Swaziland and South Africa to the southwest . It is separated from Madagascar by the ___MASK53___ to the east . The capital and largest city is Maputo ( known as " Lourenço Marques " before independence ). Malawi ( or ; or [ maláwi ]), officially the Republic of Malawi , is a landlocked country in southeast Africa that was formerly known as Nyasaland . It is bordered by Zambia to the northwest , Tanzania to the northeast , and Mozambique on the east , south and west . The country is separated from Tanzania and Mozambique by ___MASK95___ . Malawi is over with an estimated population of 16 , 777 , 547 ( July 2013 est .). Its capital is Lilongwe , which is also Malawi ' s largest city ; the second largest is Blantyre , the third is Mzuzu and the fourth largest is its old capital Zomba . The name Malawi comes from the Maravi , an old name of the Nyanja people that inhabit the area . The country is also nicknamed " The Warm Heart of Africa ".