Izazinzulu ziye zafumanisa indawo enkulu, engaphononongwayo yeenduli kunye neentlambo ezimile yimilambo yamandulo phantsi komkhenkce we-Antarctic, umkhenkce kwizigidi zeminyaka. Esi sibhakabhaka sifihliweyo, sikhulu kune Bheljiyam, ibingaphazanyiswa iminyaka engaphezu kwezigidi ezingama-34 kodwa ijongene nomngcipheko wokuvezwa ngenxa ukufudumala kwehlabathi okubangelwa ngabantu, ngokutsho kwabaphandi baseBrithani nabaseMelika.
Stewart Jamieson, ingcali yomkhenkce evela kwiYunivesithi yaseDurham, yabethelela ukuba lo ngumhlaba ongafunyaniswanga ngokupheleleyo ekungazange kubonwe mntu ngaphambili.
“Into eyonwabisayo kukuba ibizifihle apho phambi kwamehlo,” wongeze watsho uJamieson, egxininisa ukuba abaphandi abakhange basebenzise idatha entsha, yindlela entsha kuphela. Umhlaba ongaphantsi koMkhenkce oseMpuma we-Antarctic awaziwa kangako kunomphezulu weMars, utshilo uJamieson.
Ukuphonononga indawo efihlakeleyo phantsi komkhenkce we-Antarctic kwizigidi zeminyaka, izazinzulu zisebenzisa isandi serediyo-echo, apho iinqwelomoya zithumela amaza onomathotholo emkhenkceni kwaye zihlalutye i-echoes. Nangona kunjalo, ukugubungela ummandla omkhulu we-Antarctica ngale ndlela ngumngeni omkhulu. Kunoko, abaphandi basebenzisa imifanekiso yesathelayithi ukuze bachonge iintlambo neenduli ezikumgama ongaphezu kweekhilomitha ezimbini ngaphantsi komkhenkce. Umphezulu womkhenkce “ongaguquguqukiyo” usebenza “njengomfanekiso wesiporho” ofihla ezi mpawu zahlukileyo ngaphantsi kwawo.
Ngokudibanisa imifanekiso yesathelayithi kunye nedatha yokuvakala kwerediyo-echo, izazinzulu ziveze imbonakalo yomhlaba enentlambo ezinzulu ezenziwe ngumlambo kunye neenduli ezimagqagala, ezifana nezinye ezisemhlabeni.
UStewart Jamieson wafanisa umhlaba osandul’ ukufunyanwa ngaphantsi komkhenkce weAntarctic nokujonga ngefestile yenqwelo-moya kummandla osezintabeni, ofana nommandla waseSnowdonia osemantla weWales. Lo mmandla mkhulu oziikhilomitha ezingama-32,000 ngaphambili wawumiwe yimithi, amahlathi, mhlawumbi nezilwanyana ezahlukahlukeneyo.
'Kodwa emva koko kwafika umkhenkce, kwaye kwaba"engumkhenkce ngexesha"', utshilo uJamieson.
Ixesha elichanekileyo kususela ekufikeni kokukhanya kwelanga kulo mhlaba ufihliweyo kulucelomngeni ukuliqinisekisa, kodwa izazinzulu ziqinisekile ukuba sele yiminyaka eyi-14 lezigidi ubuncinane. Uqikelelo olufundileyo lukaStewart Jamieson lwelokuba lwagqityelwa ukuvezwa kwiminyaka engaphezu kwama-34 ezigidi eyadlulayo xa i-Antarctica yaqala ukukhenkceza.
Ukongeza koku kufunyaniswayo, abanye abaphandi babekhe bafumana ichibi elilingana nesixeko esingaphantsi komkhenkce weAntarctic. Bakholelwa ukuba kusenokubakho imimandla emininzi yamandulo elindele ukutyhilwa.
Ababhali bolu phononongo bavakalise inkxalabo yokuba ubushushu behlabathi bunokubeka esichengeni lo mhlaba usandula ukutyhilwa, njengoko iimeko zangoku zithe gqolo ukuya kwezo zazikho kwi-14 ukuya kwi-34 yezigidi zeminyaka eyadlulayo xa amaqondo obushushu ayengamaqondo amathathu ukuya kwasixhenxe ngokufudumala ngokukaCelsius kunanamhlanje. Nangona kunjalo, kubalulekile ukuqaphela ukuba le mbonakalo yomhlaba ibekwe kumakhulu eekhilomitha phakathi kwelizwe ukusuka kwincam yomkhenkce, ngoko ke nakuphi na ukuvezwa okunokwenzeka yinto enokwenzeka ekude.
Imbonakalo-mhlaba esandula ukufunyanwa imi kumakhulu eekhilomitha phakathi emhlabeni ukusuka kwincam yomkhenkce, okuthetha ukuba nakuphi na ukuvezwa okunokubakho kukude. Ngaphandle kweziganeko ezidlulileyo zokufudumala, njengexesha lePliocene kwi-3 ukuya kwi-4.5 yezigidi zeminyaka eyadlulayo, engabangeli ukuvezwa, kukho ithemba. Nangona kunjalo, akuqinisekanga ukuba "impendulo ebalekayo" yokunyibilika, ukuba ikhona, inokwenzeka, ngokukaJamieson.
Uphononongo lwapapashwa kungekudala emva kokuba izazinzulu zikhuphe isilumkiso sokuba ukunyibilika kwe-Ice Sheet ekufuphi ne-West Antarctic kulindeleke ukuba kukhawuleze kakhulu kumashumi eminyaka ezayo, nokuba iinzame zehlabathi zokunciphisa ukufudumala kwehlabathi ziphumelele.
I-West Antarctic Ice Sheet (WAIS) lelinye lamaqhekeza amabini amakhulu omkhenkce e-Antarctica, elinye iliPhepha lomkhenkce eliseMpuma ye-Antarctic.
Funda "Indlela uTshintsho lweMozulu eYurophu luchaphazela ngayo uKhenketho kuMazwe aseMantla…"
Ukunyuka kwamaqondo obushushu ngaphakathi iYurophu zibangela ukuba abakhenkethi bacingele amazwe asemantla njenge Dominikha njengeendawo zokuphumla ezinokubakho. Nangona kunjalo, owona mbuzo ukhoyo ngowokuba- lulunge kangakanani ukhenketho olwandisiweyo ngenxa yokutshintsha kwemozulu luyinzuzo eDenmark?
Funda Okuninzi
