Kunezindawo ezinjalo kwiplanethi yethu enhle, esondela okuyingozi kakhulu empilweni. Enye yalezi zindawo yiLake Nyos eCameroon (kwesinye isikhathi kutholakala igama elithi Nyos). Akugcwali ndawo, akunaziphepho noma izishingishane, abantu abaminzi kuwo, akukho nhlanzi enkulu noma izilwane ezingaziwa ezihlangatshezwe lapha. Kwenzenjani? Kungani leli chibi lifanelwe isihloko sechibi eliyingozi kakhulu?
Incazelo yeLake Nyos
Ngokuya ngezici zangaphandle, azikho izehlakalo ezibulalayo ezishayayo. ILake Nyos incane uma kuqhathaniswa, ineminyaka engamakhulu amane kuphela ubudala. Kuqhamuke lapho imar, intaba-mlilo wentaba-mlilo eyisicaba, yagcwala amanzi, endaweni ephakeme ngamamitha ayi-1090 ngaphezu kogu lolwandle. Ichibi lincane, indawo engaphansi ingaphansi kuka-1.6 km2, ubukhulu obumaphakathi bungu-1.4x0.9 km. Usayizi ongabalulekile wenziwa ukujula okumangalisayo kwedamu - kuze kufike ku-209 m. Ngendlela, egqumeni elifanayo lentaba-mlilo, kodwa ngakolunye uhlangothi, kunelinye ichibi eliyingozi iManun, elinokujula kwamamitha angama-95.
Esikhathini esingengakanani esidlule, amanzi asemachibini ayesobala, enombala omuhle oluhlaza okwesibhakabhaka. Umhlaba osezigodini eziphakeme zezintaba nasemagqumeni aluhlaza uvundile kakhulu, okuhehe abantu abatshala imikhiqizo yezolimo futhi bafuye imfuyo.
Umsebenzi wentaba-mlilo usaqhubeka ekwakhekeni kwedwala lapho kukhona amachibi womabili. I-Carbon dioxide, etholakala ngaphansi kwe-magma plug, ibheka indlela yokuphuma, ithola imifantu ezinsikeni ezingezansi zamachibi, ingena emanzini ngayo bese incibilika emkhathini ngaphandle kokulimaza. Lokhu kwaqhubeka kwaze kwaba ngama-80s wekhulu lama-XX.
Inkathazo ye-limnological echibini
Igama elingenakuqondakala kwabaningi, ososayensi babiza into eyenzeka lapho kukhishwa umthamo omkhulu wegesi echibini elivulekile, eliholela ekulahlekelweni okukhulu phakathi kwabantu nezilwane. Lokhu kwenzeka ngenxa yokuvuza kwegesi kusuka ezingxenyeni ezijulile zomhlaba ngaphansi kwezansi kwechibi. Ukuze kwenzeke inhlekelele yemvelo, kudingeka izimo eziningana:
- Ukufakwa kwe- "trigger". Umfutho wokuqala kwesimo esiyingozi kungaba ukuqhuma kwentaba-mlilo ngaphansi kwamanzi, udaka olungena emanzini, ukudilika komhlaba echibini, ukuzamazama komhlaba, imimoya enamandla, imvula nezinye izenzakalo.
- Ukuba khona kwevolumu enkulu yesikhutha phakathi kwamanzi noma ukukhululwa kwayo okucijile kusuka ngaphansi kwezidumbu ezingezansi.
Sikukwazisa ukuthi ubheke echibini iBaikal.
Kwenzeka ukuthi ngo-Agasti 21, 1986, "i-trigger" efanayo yasebenza. Yini eyayinomfutho kuye akwaziwa ngokuqinisekile. Akukho mkhondo wokuqhuma, ukuzamazama komhlaba noma ukudilika komhlaba okutholakele, futhi abukho ubufakazi bokuthi kunemimoya enamandla noma imvula etholakele. Cishe kukhona ukuxhumana nenani eliphansi lemvula endaweni kusukela ngo-1983, okwaholela ekutheni kube negesi ephezulu emanzini echibi.
Noma kungaba njani, ngalolo suku, kwaqhuma isamba esikhulu segesi kukholamu lamanzi emthonjeni ophakeme, sasakazeka njengefu phezu kwendawo ezungezile. Igesi esindayo efwini le-erosol esakazekayo laqala ukuhlala phansi futhi laminza yonke impilo. Ensimini efinyelela kumakhilomitha angama-27 ukusuka echibini ngalolo suku, abantu abangaphezu kwe-1700 nazo zonke izilwane bavalelisa izimpilo zabo. Amanzi echibi aba nodaka futhi aba nodaka.
Ngemuva kwalesi sehlakalo esikhulu, kwenzeka into ebulalayo eLake Manun, eyenzeka ngo-Agasti 15, 1984 ngaphansi kwezimo ezifanayo. Bese kuthi abantu abangama-37 balahlekelwe yizimpilo zabo.
Izinyathelo zokuvimbela
Ngemuva kwale micimbi eLake Nyos eCameroon, iziphathimandla zabona isidingo sokuqapha njalo isimo samanzi kanye nentaba-mlilo endaweni ukuze u-1986 ungaziphindi. Ngezindlela eziningi zokuvimbela lezi zimo (ukukhuphula noma ukwehlisa izinga lamanzi echibini, ukuqinisa amabhange noma inhlabathi engezansi, i-degassing) esimweni samachibi iNios neManun, kukhethwe i-degassing. Isetshenziswe kusukela ngo-2001 nango-2003, ngokulandelana. Izakhamizi ezisusiwe manje zibuyela emakhaya kancane kancane.
