Antarctica—Izwekazi Elisenkingeni

INCWADI ethi Antarctica: The Last Continent, ithi lapho osomkhathi bebuka umhlaba besemkhathini, isici esiphawuleka kakhulu kuyiplanethi yethu yiqhwa elimboze i-Antarctica. Osomkhathi babika ukuthi “likhanya kuhle kwesibani esikhulu sikaphalafini esikhanyisa kuyo yonke indawo yomhlaba eseningizimu.”

Njengoba ineqhwa elingaba ama-cubic khilomitha ayizigidi ezingu-30, i-Antarctica iyizwekazi elikhiqiza iqhwa. Iqhwa eliyinkephunkephu liyakhithika kuleli zwekazi futhi ligqisheke phansi lakhe iqhwa eliwugqinsi. Amandla adonsela phansi aphoqelela leli qhwa ukuba likhukhuleke kancane kancane lehlele ogwini, lingene olwandle lakhe izingqimba ezinkulu zeqhwa.—Bheka ibhokisi elisekhasini 18.

Izingqimba Zeqhwa Ezincibilikayo

Nokho, eminyakeni yamuva nje, ukuncibilika kweqhwa ngokushesha kuye kwanciphisa izingqimba zeqhwa eziningi, futhi ezinye ziye zanyamalala ngokuphelele. Umbiko othile uthi ngo-1995 ingxenye engamakhilomitha-skwele angu-1 300 yeLarsen Ice Shelf enobude obungamakhilomitha angu-1 000 yaqhephuka yaba izinkulungwane zezinguzunga zeqhwa.

Okwamanje iNhlonhlo ye-Antarctica iyona eye yathinteka kakhulu kulokhu kuncibilika kweqhwa. Le nhlonhlo emise okuka-S eyingxenye yentaba i-Andes yaseNingizimu Melika, iye yaba nokuphakama kwezinga lokushisa elingu-2,5° C. kule minyaka engu-50 edlule. Ngenxa yalokho, iJames Ross Island, eyayikade ivalwe yiqhwa, manje isingajikelezwa. Iqhwa elincibilikayo liye labangela nokwanda okukhulu kohlaza.

Ngenxa yokuthi ukuncibilika kweqhwa okukhulu kuye kwenzeka eNhlonhlweni Ye-Antarctica kuphela, izazi zesayensi ezithile azikholelwa ukuthi lokhu kuwuphawu lokufudumala kwembulunga. Nokho, ngokokucwaninga okwenziwa eNorway, iqhwa lase-Arctic nalo seliyancipha. (Ngenxa yokuthi iNorth Pole ayinayo inhlabathi, iqhwa eliningi lase-Arctic lakhiwa amanzi olwandle ayiqhwa.) Ngokwalokhu kucwaninga, lonke lolu shintsho lufana ncamashí nokwakubikezelwe ukuthi kuzokwenzeka uma imbulunga isifudumala.

Kodwa kunokuningi okuthinta i-Antarctica kunamazinga okushisa. Leli zwekazi liye lachazwa “njengesizinda esibalulekile esilawula amazinga okushisa ezindaweni eziningi embulungeni yethu.” Uma kunjalo, khona-ke isimo sezulu singase sithinteke esikhathini esizayo uma leli zwekazi liqhubeka nezinguquko.

Okwamanje, ngenhla kwe-Antarctica kuye kwavuleka imbobo enkulu ngokuphindwe kabili kunezwe laseYurophu ongqimbeni lwe-ozone olusemkhathini. I-ozone, ewuhlobo oluthile lomoya-mpilo, ivikela umhlaba emisebeni yelanga elimaza amehlo futhi eyimbangela yomdlavuza wesikhumba. Ngenxa yokwanda kwemisebe e-Antarctica, abacwaningi kumelwe bavikele isikhumba sabo elangeni futhi bagqoke izibuko zamehlo ezinengilazi ekhethekile ukuze bavikele amehlo abo. Kuyobonakala ngokuhamba kwesikhathi ukuthi zithinteka kanjani izilwane zasendle ezifika e-Antarctica ngezikhathi ezithile.

Izwekazi Elintekenteke—Nyathela Ngokucophelela

Isihloko esingenhla singaba indlela efanelekayo yokwamukela izivakashi e-Antarctica. Kungani kunjalo? Kungenxa yezizathu eziningi, ngokusho kwe-Australian Antarctic Division. Okokuqala, ngenxa yesimo esingokwemvelo esintekenteke sase-Antarctica, indawo ezungezile iyashesha ukuzwela uma iphazamiseka. Okwesibili, kuthatha isikhathi eside ukuba izitshalo zikhule kangangokuba isinyathelo esishiywa unyawo otshanini singalokhu sibonakala nangemva kweminyaka eyishumi. Izitshalo ezilimele noma ezibuthakathaka zingaqothulwa yizivunguvungu ezinkulu, ezingabhubhisa zonke izitshalo. Okwesithathu, ukubanda okwedlulele kusho ukuthi kungathatha amashumi eminyaka ukuba imfucumfucu ibole. Okwesine, abantu bangase balethe izinhlobo zokuphila ezincane ezingajwayelekile kuleli zwekazi elingalodwa nelibuthakathaka bengaqondile. Okokugcina, izivakashi nezazi zesayensi zivame ukuvakashela izindawo ezingasogwini—izindawo ezithandwa kakhulu izilwane zasendle nohlaza. Ngenxa yokuthi lezi zindawo zakha amaphesenti amabili nje kuphela alo lonke leli zwekazi, kulula ukubona ukuthi kungenzeka i-Antarctica iminyane ngokushesha. Lokhu kuphakamisa umbuzo othi, Ubani oqaphe leli zwekazi elikhulu?

Ubani Obusa I-Antarctica?

Nakuba amazwe angu-7 ephethe izingxenye ezithile ze-Antarctica, lilonke leli zwekazi liyingqayizivele ngoba alinawo umbuso olibusayo futhi alinazo nezakhamuzi. I-Australian Antarctic Division iyabika: “I-Antarctica iwukuphela kwezwekazi emhlabeni elibuswa isivumelwano samazwe ngamazwe.”

Isivumelwano esasayinwa ohulumeni abangu-12 esibizwa ngokuthi i-Antarctic Treaty, saqala ukusebenza ngo-June 23, 1961. Kusukela ngaleso sikhathi, inani lamazwe aye ahlanganyela kuso liye landa laba amazwe angaphezu kuka-40. Injongo yalesi sivumelwano “ukuqinisekisa, ngokwenzuzo yaso sonke isintu, ukuthi i-Antarctica iyoqhubeka njalo isetshenziselwa kuphela izinjongo zokuthula futhi ingabi isisusa sokungezwani kwamazwe omhlaba.”

Ngo-January 1998 i-Environmental Protection Protocol enezela kuyi-Antarctic Treaty yaqala ukusebenza. Lesi sivumelwano senqabela zonke izinhlobo zezimayini nokumbiwa kwamaminerali e-Antarctica iminyaka engengaphansi kwengu-50. Futhi sibheka leli zwekazi nesimiso salo sezinto eziphila olwandle “njengendawo yokulondoloza imvelo ethuthukisa ukuthula nesayensi.” Yenqatshelwe imisebenzi yezempi, ukuhlola izikhali nokulahla imfucumfucu yenuzi. Ngisho nezinja ezidonsa izihlibhi zenqatshelwe.

I-Antarctic Treaty iye yanconywa “njengesibonelo esingenakuqhathaniswa sokubambisana kwamazwe omhlaba.” Nokho, kusenezinkinga eziningi okumelwe zixazululwe, ezihlanganisa nobubusi. Ngokwesibonelo, ubani oyoqinisekisa ukuthi lesi sivumelwano siyalandelwa, futhi uyokwenza kanjani lokho? Futhi izizwe ezingamalungu ziyobhekana kanjani nokwanda okusheshayo kwenani lezivakashi—okungase kube usongo esimisweni semvelo esintekenteke sase-Antarctica? Eminyakeni yamuva izivakashi ezihamba ngomkhumbi ezingaphezu kuka-7 000 zivakashela e-Antarctica minyaka yonke, futhi kulindeleke ukuba leli nani liphindeke kabili maduze nje.

Kungase kuphakame ezinye izinselele esikhathini esizayo. Ngokwesibonelo, kuthiwani uma ososayensi bethola amaminerali ayigugu noma uwoyela? Ingabe lesi sivumelwano siyokuvimbela ukuxhaphaza kwezentengiselwano nokungcola okuvame ukuba umphumela? Izivumelwano zingashintshwa, futhi kunjalo nangeSivumelwano Sase-Antarctica. Empeleni, iSiphakamiso 12 sinelungiselelo lokuba lesi sivumelwano “sichitshiyelwe noma sishintshwe nganoma yisiphi isikhathi uma nje bevumelana Labo Abasenzile.”

Yiqiniso, asikho isivumelwano esingakwazi ukuvikela i-Antarctica ekungcoleni okubangelwa amazwe esimanje athuthukile. Kuyoba into edabukisayo uma “isibani esikhulu” esihle esiseningizimu nembulunga besingangcoliswa imiphumela enamandla yobugovu nokunganaki kwesintu! Ukona i-Antarctica kuwukulimaza uhlanga lwesintu. Uma kukhona esikufundayo kuyi-Antarctica, kuwukuthi umhlaba wonke—njengomzimba womuntu—uyisimiso esihlobene, esihlelwe uMdali ngendlela ephelele ukuze silondoloze ukuphila futhi sisenze sijabule.

[Ibhokisi/Isithombe ekhasini 18]

IYINI I-ICE SHELF?

Phezulu enkabeni ye-Antarctica, imifula yeqhwa elikhithikayo elinqwabelene yehlela ogwini—eminye igeleza ibanga elingangekhilomitha ngonyaka, ngokwemifanekiso yamuva ethathwe ngesiphuphutheki. Eminingi kule mifula yeqhwa ihlangana njengemingenela, yakhe imifula yeqhwa emikhulu. Lapho isifike olwandle, la makhekheba ayiqhwa antanta emanzini akhe ungqimba lweqhwa, olukhulu ukuzedlula zonke, iRoss Ice Shelf (eboniswe lapha). Njengoba yakhiwa izingqimba noma izinguzunga zeqhwa ezingaba ngu-7, ilingana nezwe laseFrance ngobukhulu futhi iwungqimba oluwugqinsi olungaba ikhilomitha kwezinye izindawo.a

Ezimweni ezivamile, izingqimba zeqhwa azincibiliki. Njengoba izinguzunga zeqhwa zinqwabelanisa iqhwa kulolu ngqimba, ingxenye engaphandle yongqimba iyaqhubeka ingenele olwandle, njengomuthi wokuxubha oputshuka eshubhwini. Ekugcineni lezi zigaxa ezinkulu ziyahlephuka (inqubo ebizwa ngokuthi i-caling), bese ziba izintaba zeqhwa. I-World Book Encyclopedia ithi ezinye izintaba zeqhwa “zinobukhulu obungangamakhilomitha-skwele angu-13 000.” Nokho, eminyakeni yamuva inqubo ye-calving iya yanda futhi izingqimba zeqhwa ziye zancibilika, ezinye zaze zanyamalala zaphela. Noma kunjalo, lokhu akuwandisi umthamo wolwandle. Ngani? Ngoba kakade izingqimba zeqhwa ziyantanta, futhi isisindo sazo sithwalwa amanzi. Kodwa uma iqhwa elisezwekazini lase-Antarctica belingancibilika, bekuyofana nokuthela olwandle amanzi asedanyini elingama-cubic khilomitha angu-30 000 000! Umthamo wolwandle ubungaphakama ngamamitha angu-65!

[Umbhalo waphansi]

[Isithombe]

Izigaxa ezinkulu zeqhwa ziyahlephuka kuyi-Ross Ice Shelf. Lapha, le nguzunga yeqhwa iphakeme ngamamitha angu-65 ngaphezu kogu lolwandle

[Umthombo]

Tui De Roy

[Isithombe ekhasini 20]

Izinyane lemvu yamanzi i-“Weddell”

[Umthombo]

Photo: Commander John Bortniak, NOAA Corps