Izimangaliso Nezimfihlakalo Ezisekujuleni Kolwandle
BEGIBELE umkhumbi-ngwenya wabo omncane okuthiwa i-Alvin, ososayensi ababili nomshayeli wabo behlela ekujuleni kwePacific Ocean ngasogwini lwe-Ecuador. Babelibangisephi? Endaweni okuthiwa iGalápagos Rift. Uhlome ngezibani zokukhanyisa, ikhamera nedlanzana lamanye amathuluzi esayensi, umkhumbi-ngwenya i-Alvin wehlela endaweni emnyama ejule ngamamitha angu-2 800, engakaze ibonwe muntu ngamehlo.
Wake wazibuza ukuthi yini efihlwe yizintaba, imihosha nemifantu engaphansi kolwandle? Uma kunjalo, uyokujabulela ukufunda ngezinto eziye zatholakala kusukela ngo-1977 ohambweni lokuqala lwe-Alvin okukhulunywe ngalo ngenhla. Lokho okwabonwa abagibeli kungase kukumangalise; ngisho nososayensi abachwepheshile kwaba sengathi babona ukuphila kwenye iplanethi.
Inhloso yohambo lwe-Alvin kwakuwukuthola imithombo yamanzi ashisayo—imigodi engaphansi kolwandle ekhipha amanzi ashisayo. IGalápagos Rift kwakuyindawo efanelekayo ngoba iyingxenye yemihosha engaphansi kolwandle enezintaba-mlilo ezinamandla ezizungezwe ukhahlamba oluzungeza imbulunga yonke okuthiwa ukhahlamba lwasolwandle. Njengoba luyibanga elingamakhilomitha angaphezu kuka-65 000, lolu khahlamba olukhulu luzungeza imbulunga yonke njengomugqa omhlophe webhola lomphebezo. Uma bekungasuswa amanzi olwandle, beluyoba “yisici esivelele kunazo zonke ebusweni bomhlaba, luhlanganise indawo enkulu kuneyazo zonke izintaba zomhlaba zihlangene,” kubhala uJon Erickson encwadini yakhe ethi Marine Geology.
Isici esivelele kakhulu salolu khahlamba lwasolwandle ukuthi luhlukene kabili ngokuyisisekelo—luyizintaba ezimbili eziwukhahlamba eziqondene futhi ezingamamitha angu-3 000 ukuphakama kusuka ekujuleni kolwandle. Phakathi kwalezi zintaba kunamawa amakhulu kunawo wonke emhlabeni—imihosha engaba amakhilomitha angu-20 ububanzi namakhilomitha ayisithupha ukujula—ejule ngokuphindwe kane kuneGrand Canyon yaseNyakatho Melika! Phansi kula mawa kunezindawo ezinezigodi zezintaba-mlilo eziqhuma njalo. U-Erickson uthi lapho ososayensi beqala ukuhlola ingxenye yase-Atlantic yalolu khahlamba, ebizwa ngokuthi iMid-Atlantic Ridge, amathuluzi abo embula ukuthi kunezintaba-mlilo ezinamandla “kangangokuthi kwakubonakala sengathi amathumbu oMhlaba aphumela ngaphandle.”
Ngemva kokwehla imizuzu engu-90, umkhumbi-ngwenya i-Alvin wacishe wathi cababa phansi olwandle, la madoda abe esekhanyisa izibani zomkhumbi-ngwenya. Kuyaqondakala ukuthi kungani lab’ ososayensi babecabanga ukuthi bakwenye iplanethi. Izibani zabo zembula imithombo eminingana yamanzi ashisayo esekujuleni kolwandle, lapho amanzi ecishe abe yiqhwa khona. Eduze kwale migodi, kwavela okuthile okuyisimanga ngisho nakakhulu—inqwaba yezinto eziphilayo ezazingaziwa ngaphambili. Eminyakeni emibili kamuva, abacwaningi ababegibele i-Alvin bathola imigodi eshisayo ebizwa ngokuthi ama-smoker e-East Pacific Rise ngasogwini lweMexico. Idlanzana lale migodi lalime njengoshimula abayinqaba, abanye abangaba amamitha angu-9 ukuphakama. Izilwane eziningi ezabonwa eGalápagos Rift zatholakala kule ndawo. Esihlokweni esilandelayo, sizohlolisisa lezi zidalwa ezimangalisayo kanye nezwe eliyinqaba ezihlala kulo.
[Umthombo Wesithombe ekhasini 3]
COVER and page 3: OAR/National Undersea Research Program