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The hydrosphere (frae Greek ὕδωρ - hudōr, "watter"[1] an σφαῖρα - sphaira, "sphere"[2]) in pheesical geografie describes the combined mass o watter foond on, unner, an ower the surface o a planet.

Igor Shiklomanov, the man selectit bi the Unitit Naitions tae dae its warld inventory o watter resoorces, [3] estimatit that there are 1386 million cubic kilometres o watter on yird.[4] This includes watter in liquid an frozen furms in grundwatters, glaciers, oceans, lochs an streams. Saline watter accoont for 97.5% o this amoont. Fresh watter acoonts for anly 2.5%. O this fresh watter 68.7% is in the "furm o ice an permanent snow cover in the Arctic, the Antarctic, an in the muntainous regions. Next, 29.9% exists as fresh grundwatters. Anly 0.26% o the tot amount o fresh watters on the Yird are concentrated in lochs, reservoirs an river seestems whaur thay are maist easily accessible for oor economic needs an absolutely vital for watter ecoseestems."[4] The tot mass o the Yird's hydrosphere is aboot 1.4 × 1018 tonnes, which is aboot 0.023% o the Yird's tot mass. Aboot 20 × 1012 tonnes o this is in the Yird's atmosphere (the volume o ane tonne o watter is approximately 1 cubic metre). Approximately 75% o the Yird's surface, an aurie o some 361 million square kilometers (139.5 million square miles), is covered bi ocean. The average salinity o the Yird's oceans is aboot 35 grams o saut per kilogram o sea watter (3.5%) [5]

References[eedit | eedit soorce]

  1. ὕδωρ, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
  2. σφαῖρα, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
  3. Marq de Villiers (2003). Water: The Fate of Our Most Precious Resource (2 ed.). Toronto, Ontario: McClelland & Stewart. p. 453. ISBN 978-0-7710-2641-6. OCLC 43365804. , revised 2003|Governor General's Award (1999)
  4. 4.0 4.1 World Water Resources: A New Appraisal and Assessment for the 21st Century (Report). UNESCO. 1998. http://webworld.unesco.org/water/ihp/publications/waterway/webpc/world_water_resources.html. Retrieved 13 June 2013. 
  5. Kennish, Michael J. (2001). Practical handbook of marine science. Marine science series (3rd ed.). CRC Press. p. 35. ISBN 0-8493-2391-6.