Ulwandle ngummandla omkhulu wamanzi anetyuwa phakathi kwamazwekazi. Iilwandle zinkulu kakhulu kwaye zidibana nezinye iilwandle ezincinci zitsho zimanyane. Xa zidibene zizonke, iilwandle zibangathi ‘’zilulwandle’’ olunye, kuba zonke iilwandle zimanyene. Iilwandle (okanye ii-marine biome) zithatha ama-70% zeli hlabathi siphila kulo. [1]

OLwandle lwase-Atlantic

Olona lwandle lude yi-Pacific Ocean. Lithatha umhlaba ongekuhamnjwa kuwo ongange-1/3 (yesiqingatha)somhlaba esiphila kuwo. Igama lolona lwandle luncinane kuthiwa yi-Arctic Ocean. Iindlela zeentshukumo zamanzi zizo ezahlula Ulwandle olusemaZantsi ehlabathi kwezinye iilwandle ezifana ne-Atlantic, i-Pacific and nolwase-India. Olu lwandle lukwaziya ngegama elithi yi-Antarctic, kuba kaloku igubungele yonke ingingqi ejikeleze i- Antarctica. Imephu ezindala zisenokungawsebenzisi amagama athi-ulwandle i-Arctic nelithi ulwandle UmZantsi lwandle. Olona lwandle lunzulu yi-Pacific. Esona siza sinzulu yi-Mariana Trench, ubunzulu baso buziimitha ezili-11,000 (36,200 beenyawo). Eyona nto bubonakala ngayo ubunzulu bolwandle yingqele eqhaqhazelisa amazinyo, ukunyuka koxinzelelo lomoya, nobumnyama obugqibeleleyo. Ezinye iintlobo zezilwanyana ezingaqhelelaka kwaphela ziphila kanye kule ndawo yolwandle. Aziphili ngamandla avela elangeni ukuze, kuba zisebenzisa iityuwa ezifumaneka ngaphantsi komhlaba.

Isimboli ecetywayo ye-Iilwandle ngu-🜨.

Nangona uninzi lwabantu lukholelwa ekubeni iilwandle ziluhlaza kuba isibhaka-bhaka sisiba sisipili kuzo, eneneni oku akusiyonyaniso. Amanzi anayo indawo yokubaluhlaza ngokombala kodwa ke lo mbala wamanzi ungabonakala kuphela xa kukho amanzi amaninzi. Kodwa ke esona sizathu sokuba iilwandle zibeluhlaza ngokwebala kukuba amanzi afunxa laandawo imbala ubomvu apha elangeni, kuze kubonakale le ndawo iluhlaza apha ekukhanyeni. Sitsho sikubone ke thina oku kukhanya kubonakalayo ngokungathi ngumbala wamanzi.

 
Umbala wamanzi oluhlaza

Izityalo nezilwanyana

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Izinto eziphila elwandle zinakho ukuphila kumanzi anetyuwa. Ziyaphazamiseka kukukhanya kwelanga, bubushushu, luxinzelelo lwasemanzini, yintshukumo yamanzi. Intlobo-ntlobo zezinto eziphila emanzini ziphila kakuhle xa zikufutshane nomphezulu wolwandle, kumanzi abanzi, nakumanzi anzulu. Ezo ziphila kufuphi nomphezulu wolwandle nezo zikwaxhomekeke kwimitha yelanga ukuze zikwazi ukuvelisa ukutya kuthiwa zii-phytoplankton. Phantse zonke izilwanyana zaselwandle zixhomekeke ngqo okanye (ngezinye iindlela) kwezi zityalo ukuze ziphile. Kumanzi abanzi, uyakufumana oorhexe kunye noononkala. Kumanzi anzulu, izilwanyana zolwandle ezikumila kuziindi-ngeendidi kwanobukhulu bazo ngkunjalo zidada ngokukhululekileyo elwandle. Ezi zibandakanya iintlobo-ntlobo zeentlanzi, ezifana nentlanzi yamanzanetyuwa i-tuna, udwayi olude lwentlanzi ethand'ukuhamba i-sword kunye nezilwanyana zamanzi ezincancisayo ezifana nee-dolphin kunye nee-whales. Kwisibhaka-bhaka phezu kolwandle olukhamisileyo likhaya leentaka ezinkulu zolwandle, ezifana nee-albatross.[1]

Ukuvunwa kolwandle

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Amazwe afana ne-Russia, kunyeneJapan, anenqwaba yeenqanawa ezinkulu ezihamba kumazwe athile angawona aneendawo kunokuthatyathwa iinyanga ezininzi kulotywa kuzo. Ezi nqanawakazi zinamathala eencwadi amakhulu, izibhedlele, izikolo.

Abantu abaninzi balubona ulwandle njengomthombo wokutya, izimbiwa namandla.

Abafoti elwandle (ii-Oceanographers) ziqikelela okokuba zingaphaya kwama-15, 300 iintlanzi eziphila elwandle, ezinye zazo ziyatyiwa .[2] Intlazi kukutya okungumthombo wee-proteni, baninzi kakhulu abantu abayityayo. Ushishino ngokuloba industries lubaluleke kakhulu kuba luza nemisebenzi, luncede nezigidi-ngezigidi zabantu ngokutya. Namhlanje, njengesiqhelo ngenxa yokuloba elwandle, ulwandle lusinika ii-calories ezifunwa ngabantu ezimalunga ne-2%.[2] I-tuna, ii-ankhovi, kunye ne-herring zivunwa kufuphi nomphezulu wolwandle. [2] Pollock, flounder kunye ne-cod zibanjwa kufuphi nalapho luphela khona ulwandle ngaphantsi, [2] Zingaphezulu kwesigidi ii-toni zee-herring ezibanjwa qho ngonyaka kumNtla we-Pacific, nakumNtla we-Atlantic, kwaye phantse zisibhozo kwezilishumi iintlanzi ezityiwayo ngabantu. Ezinye iintlanzi zisetyenziselwa njenge sichumisi, isincamathelitsi, kunye nokutya kweekati nezinye izilwanyana.[2]

Ubushushu bolwandle

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Maninzi amaqondo obushushu bolwandle kulwandle oluvulekileyo, (kwintlangothi zombini - ukusuka phezulu ukuya ezantsi)kwanokusuka kwelinye icala ukuya kwelinye. ii-Icebergs zenziwe zaqamela ngamanzi abanda kakhulu kuyo yomibini le mida, abe wona amanzi avela kumbindi i-equator eshushu noko. [2] Amanzi apholisa ekwafudumeza ngokuthe chu kunomhlaba, ke umhlaba onikwa ifuthe lulwandle uneezigaba eziza mva zamva nezinobushushwana kunomhlaba othe qelele elwandle.

Umphezulu wolwandle, nobizwa ngokuba ngu-mxube wenwebu, awubandi kangako nditsho sesidad'elenzulwini sisiy'ezantsi. [2] emazantsi olu lwandle kulapho kukho inwebu apho kwenzeka khona utshintsho lwangesaquphe ekuthiwa xa lubizwa yi- thermocline. Le ke yinwebu esembindini ebude bayo busuka kumphezulu wolwandle buhle bubheke ezantsi ngokomlinganiselo omalunga neenyawo ezinga-2,600 (800 eemitha). Ii-Thermoclines zingenzeka kuphela ngokwamaxesha onyaka okanye zibe sisigxina, kodwa ke kungatshintsa oku, kuxhomekeke ekubeni kuphi kwaye lunzulu kangakanani na ulwandle. Nje ngoko kusenzeka umphushu, luqala ke ngoku luphole, kodwa ukuba amanzi aphuma ngokomphushu ngendlela ekhawulwzileyo, amanzi aya ngokuya evakala ityuwa. Amanzi anetyuwa nabandayo ngumehlisi wezinga lomkhenkce nelobushushu emanzini olwandle, utsho azike aye ezantsi. Yhiyo le nto amanzi ashushu nabandayo engaxubeki lula. Inkoliso yezilwanyana nezityalo ziphila kule nwebu ishushu ingaphezulu. Ezantsi kwe-thermocline, izinga lokubanda libaphezulu kakhulu, kude ukubanda kwawo kubengaphezulu kokomkhenkce - kube phakathi kwama-32 – 37.4 °F (0 – 3 °C).[2]

Ulwandlekazi

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Imithombo

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  1. 1.0 1.1 English through Science (2010) Blue Planet North America: McGrawHill pp. 117 to 118 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Sherwin, Frank (2004) The Ocean Book P.O. Box 726, Green Forest, AR 72638: Master Books ISBN 0-89051-401-1