Umehluko phakathi koLwandle noLwandle
Amanzi omhlaba amboza izindawo ezinkulu futhi eza ngezimo nobukhulu obuhlukahlukene. Amagama amabili avame ukusetshenziswa ukuchaza amanzi amakhulu “ulwandle” kanye “nolwandle.” Nakuba lawa amabili evame ukubonakala efana futhi exhumene, anomehluko omkhulu obalulekile. Kulesi sihloko, sizohlola umehluko phakathi kolwandle nolwandle ngezindlela ezahlukene, okuhlanganisa izincazelo zazo, ubukhulu, ukujula, izindima zemvelo, nokuningi.
1. Incazelo
Izilwandle ziyizindikimba ezinkulu zamanzi anosawoti amboza izindawo ezinkulu zobuso boMhlaba. Kunezilwandle ezinhlanu ezinkulu emhlabeni: uLwandlekazi iPacific, uLwandlekazi i-Atlantic, uLwandlekazi i-Indian , uLwandlekazi iSouthern, kanye noLwandlekazi i-Arctic. Izilwandle zimboza cishe u-71% wobuso boMhlaba futhi zibamba cishe u-97% wawo wonke amanzi eplanethi.
Ulwandle luyindilinga yamanzi encane kunolwandle futhi ngokuvamile luxhunywe kolunye ulwandle. Ulwandle luvame ukutholakala onqenqemeni lwezwekazi futhi luzungezwe umhlaba. Izibonelo zolwandle zifaka phakathi uLwandle iMedithera, uLwandle iCaspian, kanye noLwandle iCaribbean. Ulwandle lungahlukaniswa njengengxenye yolwandle, kodwa ngokwendawo, luncane.
2. Usayizi
Ubukhulu bungomunye wemimehluko ephawulekayo phakathi kolwandle nolwandle. Izilwandle zikhulu kakhulu kunolwandle. Isibonelo, uLwandlekazi iPacific lulwandle olukhulu kunawo wonke emhlabeni, oluhlanganisa cishe amakhilomitha-skwele ayi-168.723.000, kanti uLwandlekazi iMedithera luhlanganisa cishe amakhilomitha-skwele ayi-2.500.000. Ngakho-ke, izilwandle zivame ukuba zincane futhi zivaleleke kakhulu kunolwandle.
3. Ukujula
Ukujula kungenye into ebalulekile ehlukanisayo. Izilwandle ngokuvamile zijule kakhulu kunolwandle. Ukujula okujwayelekile kolwandle kungamamitha angu-3.688, kanti indawo ejulile kakhulu, iMariana Trench ePacific Ocean, ifinyelela ekujuleni okungamamitha angaba ngu-10.994. Izilwandle, ngakolunye uhlangothi, zivame ukuba zincane kakhulu. Isibonelo, ukujula okujwayelekile koLwandle iMedithera kungamamitha angaba ngu-1.500.
4. Imvelo kanye nokuhlukahluka kwezinto eziphilayo
Izilwandle nezilwandle zisekela izinhlobo ezahlukene zokuphila. Ngobubanzi nokujula kwazo okukhulu, izilwandle zinikeza izindawo ezahlukahlukene, kusukela ebusweni obukhanyiswe yilanga kuya ekujuleni okumnyama kakhulu nokucindezelwe. Izinhlobonhlobo zezinto eziphilayo zaselwandle zicebile kakhulu, kufaka phakathi izinhlobo eziningi zezinhlanzi, izilwane ezincelisayo zasolwandle, i-plankton, kanye nezinto eziphilayo ezincane kakhulu.
Ulwandle luphinde lusekele izinhlobo eziningi zezinto eziphilayo, kodwa izindawo zalo zemvelo zivame ukuba zicebile emanzini angajulile eduze nogu. Lokhu kungenxa yokuthi ukukhanya kwelanga kungangena kalula emanzini angajulile, kusekela inqubo ye-photosynthesis ebalulekile ezitshalweni zasolwandle kanye ne-plankton. Ama-coral reef , avame ukutholakala olwandle, aphakathi kwezindawo zemvelo ezihlukahlukene kakhulu eMhlabeni.
5. Izinga Lokushisa Nosawoti
Izinga lokushisa lamanzi kanye nosawoti nakho kuyahlukahluka phakathi kolwandle nolwandle. Izilwandle zinokuhlukahluka okukhulu kwezinga lokushisa kuye ngokuthi zikuphi. Amanzi aseduze nenkabazwe afudumele, kanti amanzi aseduze nezindawo eziphansi abandayo kakhulu. Usawoti wolwandle nawo uyahlukahluka kodwa ngokuvamile ulinganiselwa kuzingxenye ezingu-35 ngenkulungwane (ppt).
Izilwandle, ngenxa yokuba seduze nomhlaba kanye nokugeleza kwemifula, zingase zibe nokushintshashintsha okukhulu kwezinga lokushisa kanye nosawoti. Isibonelo, uLwandle iBaltic lunosawoti ophansi kakhulu kunolwandle olujwayelekile ngenxa yenani elikhulu lamanzi ahlanzekile ageleza kulo.
6. Ukusakaza kanye Nokugeleza Kwamanje
Imisinga yolwandle iyizindikimba ezinkulu zamanzi ezihamba ngamaphethini azinzile futhi zithonya isimo sezulu somhlaba wonke. Isibonelo esaziwayo yiGulf Stream eNyakatho ye-Atlantic, ethwala amanzi afudumele esuka ezindaweni ezishisayo iye enyakatho, ithonya isimo sezulu saseNtshonalanga Yurophu. Izilwandle nazo zinomsinga ojulile owaziwa ngokuthi ukujikeleza kwe-thermohaline, okuyi-"global conveyor belt" futhi obalulekile ekujikelezeni kokushisa komhlaba wonke.
Izilwandle nazo zinemisinga, kodwa ngokuvamile zincane futhi azivamile njengalezo zasezilwandle. Imisinga olwandle ivame ukuthonywa umoya, ukuma komhlaba ngaphansi kwamanzi, kanye nemisinga yolwandle . Amaphethini amanje olwandle avame ukuba sendaweni ethile futhi angahluka kakhulu kuye ngokuthi indawo injani.
7. Ithonya Labantu
Izilwandle nezilwandle zombili zithintwa yimisebenzi yabantu, yize ngezindlela ezahlukene. Izilwandle zivame ukubhekwa “njengamaphaphu eplanethi” ngenxa yekhono lazo lokumunca i-carbon dioxide futhi zikhiqize umoya-mpilo nge-photosynthesis yi-phytoplankton. Kodwa-ke, izinkinga ezifana nokungcoliswa kwepulasitiki , ukufudumala komhlaba, kanye nokudoba ngokweqile kuthinta kakhulu impilo yolwandle.
Izilwandle, ngenxa yokuba seduze kwabantu, zivame ukuthintwa kakhulu ukungcola okuqondile, njengokugeleza kwamanzi kwezolimo, ukungcola kwezimboni, kanye nemfucuza yasemadolobheni. Izilwandle eziseduze nezindawo zokuhlala zabantu nazo zinamathuba amaningi okuthintwa yimisebenzi yezentengiselwano efana nokudoba, ezokuvakasha, kanye nentuthuko yogu lolwandle.
8. Indima Emnothweni
Izilwandle nezilwandle zibalulekile emnothweni womhlaba kanye nowendawo. Izilwandle zihlinzeka ngemizila ebalulekile yokuhwebelana kwamazwe ngamazwe, kanti iningi lezimpahla zomhlaba lithuthwa olwandle. Imithombo yemvelo efana namafutha negesi nayo ikhishwa olwandle olujulile. Ngaphezu kwalokho, izilwandle zibalulekile ezimbonini ezinkulu zokudoba kanye nezokuvakasha olwandle emhlabeni jikelele.
Ulwandle, nakuba luncane, ludlala indima ebalulekile emnothweni wendawo. Ukudoba, ezokuvakasha, kanye nokuzilibazisa olwandle kuyizibonelo ezimbalwa nje zendlela ulwandle olusekela ngayo umnotho ezindaweni ezahlukene. Izimboni ezifana nokufuywa kwezinhlanzi nazo zithembele olwandle ukuze zihlinzeke ngemikhiqizo yokudla kwasolwandle.
9. I-Geology kanye Nezindawo
Umehluko wejiyoloji uphinde uhlukanise ulwandle nolwandle. Iphansi lolwandle livame ukuba nemisele yolwandle olujulile, izintaba eziphakathi kolwandle, kanye namathafa amakhulu angaphansi komhlaba. Ukwandiswa kwephansi lolwandle kanye nomsebenzi wezintaba-mlilo ngaphansi kwamanzi kungenye yezinqubo zejiyoloji ezihlotshaniswa nolwandle.
Ngakolunye uhlangothi, izilwandle zivame ukuba nezici zejiyoloji ezifana nama-bay, amabhishi, kanye nolwandle olungajulile. Zivame futhi ukuthintwa ukuguguleka komhlabathi kanye nokuchitheka komhlabathi okubangelwa ukugeleza kwemifula kanye nemisebenzi yabantu ezungezile. Ngakho-ke, izici zejiyoloji yolwandle zihlobene kakhulu nemisebenzi yomhlaba ozungezile.
10. Umthelela Wesimo Sezulu
Okokugcina, izilwandle nezilwandle zithonya isimo sezulu soMhlaba ngezindlela ezahlukene. Izilwandle zisebenza njengendawo enkulu yokucwila ukushisa kanye ne-carbon dioxide emkhathini, zithonya izinga lokushisa, amaphethini esimo sezulu, kanye nesimo sezulu somhlaba wonke. Izinqubo ezinjengokukhuphuka kanye nokuwa phansi kwezilwandle zithonya ukusatshalaliswa kwezakhamzimba kanye nokukhiqiza kwezinto eziphilayo kuzo zonke izifunda.
Ulwandle luphinde luthinte isimo sezulu sendawo nesesifunda. Isibonelo, ulwandle lunganciphisa amazinga okushisa asogwini ngethonya lomoya wasolwandle, okuholela ezimweni zezulu ezipholile nezimanzi ehlobo kanye nezifudumele ebusika.
Sekukonke, yize izilwandle nolwandle kuxhumene futhi kunezimpawu eziningi, umehluko ongenhla ubonisa ukuthi kubaluleke kangakanani ukuqonda kokubili ukuphatha nokuvikela imithombo yamanzi yoMhlaba wethu . Ukujula, ubukhulu, indima yemvelo, ithonya lomuntu, kanye nokusebenzisana nesimo sezulu ngezinye zezinto ezibalulekile ezihlukanisa izilwandle nolwandle.
