Ososayensi baye bathola indawo enkulukazi, engahloliwe yamagquma nezigodi ezakhiwe imifula yasendulo ngaphansi kweqhwa lase-Antarctic, iqhwa izigidi zeminyaka. Lo mkhathi ofihliwe, omkhulu kune Belgium, ibilokhu ingaphazanyiswa iminyaka engaphezu kwezigidi ezingu-34 kodwa ibhekene nengozi yokuchayeka ngenxa ukufudumala komhlaba okubangelwa abantu, ngokusho kwabacwaningi baseBrithani nabaseMelika.
Stewart Jamieson, isazi seqhwa saseDurham University, wagcizelela ukuthi lena indawo engakatholwa muntu ongakaze ayibone ngaphambili.
“Okujabulisayo ukuthi ibicashe lapho obala,” kwengeza uJamieson, egcizelela ukuthi abacwaningi bebengasebenzisanga idatha entsha, bebesebenzisa indlela entsha kuphela. Umhlaba ongaphansi kwe-East Antarctic Ice Sheet waziwa kancane kune-Mars, kusho u-Jamieson.
Ukuze uhlole indawo efihlekile ngaphansi kweqhwa lase-Antarctic izigidi zeminyaka, ososayensi ngokuvamile basebenzisa i-radio-echo sounding, lapho izindiza zithumela amaza omsakazo eqhweni futhi zihlaziye ama-echoes. Nokho, ukumboza udedangendlale we-Antarctica ngale ndlela kuyinselele enkulu. Kunalokho, abacwaningi basebenzisa izithombe zesathelayithi ukuze babone izigodi namagquma asendaweni engaphezu kwamakhilomitha amabili ngaphansi kweqhwa. Indawo yeqhwa “eguquguqukayo” isebenza “njengesithombe sesipoki” esifihla lezi zici ezihlukile ngaphansi kwalo.
Ngokuhlanganisa izithombe zesathelayithi nedatha yomsindo we-radio-echo, ososayensi baveze indawo enezigodi ezijulile ezakheke emifuleni namagquma aqinile, afana namanye asemhlabeni.
UStewart Jamieson ufanise indawo esanda kutholwa ngaphansi kweqhwa lase-Antarctic nokubuka ngefasitela lendiza endaweni enezintaba, efana nenyakatho yeWales yaseSnowdonia. Le ndawo enkulukazi engamakhilomitha-skwele angu-32,000 ngaphambili yayihlalwa izihlahla, amahlathi, futhi cishe nezilwane ezihlukahlukene.
'Kodwa kwabe sekufika iqhwa, futhi kwaba"iqhwa ngesikhathi"', kusho uJamieson.
Isikhathi esiqondile selokhu ukukhanya kwelanga kufinyelele kule ndawo efihliwe kuyinselele ukusiqinisekisa, kodwa ososayensi banesiqinisekiso sokuthi sekuyiminyaka okungenani eyizigidi ezingu-14. Ukuqagela okufundile kukaStewart Jamieson ukuthi kwagcina ukudalulwa eminyakeni engaphezu kwezigidi ezingu-34 edlule lapho i-Antarctica iqala ukuba yiqhwa.
Ngaphezu kwalokhu kutholakala, abanye abacwaningi ngaphambili babethole ichibi elilingana nedolobha elingaphansi kweqhwa lase-Antarctic. Bakholelwa ukuthi kungase kube nezindawo eziningi zasendulo ezilindele ukwembulwa.
Ababhali balolu cwaningo bazwakalise ukukhathazeka ngokuthi ukufudumala komhlaba kungase kubeke engcupheni le ndawo esanda kuvezwa, njengoba izimo zamanje zithambekela kulezo ezazikhona eminyakeni eyizigidi ezingu-14 kuya ku-34 edlule lapho amazinga okushisa ayefudumala kathathu kuya kwayisikhombisa kunanamuhla. Kodwa-ke, kubalulekile ukuqaphela ukuthi le ndawo itholakala emakhulwini amakhilomitha phakathi nezwe ukusuka onqenqemeni lweqhwa, ngakho-ke noma yikuphi ukuchayeka okungenzeka kuyinto ekude.
Indawo esanda kutholwa isendaweni engamakhulu amakhilomitha phakathi nezwe ukusuka onqenqemeni lweqhwa, okusho ukuthi ukuchayeka okungaba khona kukude. Naphezu kwezenzakalo ezidlule zokufudumala, njengenkathi ye-Pliocene eminyakeni eyizigidi ezi-3 kuya kwezingu-4.5 edlule, zingabangeli ukuchayeka, likhona ithemba. Kodwa-ke, akuqiniseki ukuthi "ukusabela kokubaleka" kokuncibilika, uma kukhona, kungenzeka, ngokusho kuka-Jamieson.
Lolu cwaningo lushicilelwe ngemuva nje kokuthi ososayensi bekhiphe isexwayiso sokuthi ukuncibilika kwe-Ice Sheet eseduze ne-West Antarctic kulindeleke ukuthi kusheshe kakhulu emashumini eminyaka azayo, noma ngabe imizamo yomhlaba wonke yokunciphisa ukufudumala komhlaba iphumelela.
I-West Antarctic Ice Sheet (WAIS) ingelinye lamashidi eqhwa amabili amakhulu e-Antarctica, elinye kuyi-East Antarctic Ice Sheet.
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