AmaRoma asendulo abiza intabamlilo ngokuthi unkulunkulu womlilo nobuciko bensimbi. Isiqhingi esincane esisoLwandle lwaseTyrrhenian saqanjwa ngegama lakhe, phezulu kwakhipha umlilo namafu omusi omnyama. Kamuva, zonke izintaba eziphefumula umlilo zaqanjwa ngalo nkulunkulu.
Isibalo esiqondile sezintaba-mlilo asaziwa. Kuya futhi encazelweni ye- "volcano": ngokwesibonelo, kukhona "izinkambu zentaba-mlilo" ezakha amakhulu ezikhungo ezihlukene zokuqhuma, zonke ezihambisana negumbi elifanayo le-magma, futhi okungathathwa noma kungabhekwa njenge "volcano" kuphela. Cishe kunezigidi zezintaba-mlilo ebezilokhu zisebenza kuyo yonke impilo yomhlaba. Phakathi neminyaka eyizi-10 000 edlule emhlabeni, ngokweSmithsonian Institute of Volcanology, kunezintaba-mlilo ezilinganiselwa ku-1 500 ezaziwa ukuthi bezikade zisebenza, futhi izintaba-mlilo eziningi ezingaphansi kolwandle azaziwa. Kukhona cishe ama-craters asebenzayo angama-600, awo ama-50-70 aqhuma njalo ngonyaka. Okunye kubizwa ngokuthi kuphelile.
Izintaba-mlilo ngokuvamile zihonjiswa phansi okungajulile. Kwakhiwa ukwakheka kwamaphutha noma ukufuduka koqweqwe lomhlaba. Lapho ingxenye yengubo engenhla yomhlaba noma uqweqwe oluphansi kuncibilika, kukhiwa i-magma. Intaba-mlilo empeleni iyindawo yokuvula noma yokungena lapho le magma kanye namagesi ancibilikisiwe equkethe ukuphuma kwayo. Yize kunezici eziningana ezibangela ukuqhuma kwentaba-mlilo, ezintathu zihamba phambili:
- ukuvuthwa kwe-magma;
- ingcindezi evela kumagesi ancibilikile ku-magma;
- ukujova iqoqo elisha le-magma egumbini le-magma eselivele ligcwele.
Izinqubo eziyisisekelo
Ake sixoxe kafushane ngencazelo yalezi zinqubo.
Lapho itshe ngaphakathi koMhlaba liyancibilika, ubukhulu balo buhlala bungashintshi. Umthamo owandayo udala ingxubevange enesibalo esiphansi kunaleso semvelo. Bese kuthi, ngenxa yokuthamba kwayo, le magma ekhanyayo inyukela phezulu. Uma ubukhulu be-magma phakathi kwendawo yesizukulwane sayo nobuso bungaphansi kobuncane bamadwala azungezile naphezulu, i-magma ifinyelela ngaphezulu bese iqhuma.
IMagmas yezingoma ezibizwa nge-andesitic kanye ne-rhyolite iqukethe nokuqothuka okuqhekekile njengamanzi, i-sulfur dioxide ne-carbon dioxide. Ucwaningo lukhombisile ukuthi inani legesi elichithwe ku-magma (ukuncibilika kwalo) ekucindezelekeni komkhathi kungu-zero, kepha liyanda ngokunyuka kwengcindezi.
Ku-andesite magma egcwele amanzi, etholakala ngamakhilomitha ayisithupha ukusuka ebusweni, cishe i-5% yesisindo sayo ichitheka emanzini. Njengoba lolu daka ludlulela ngaphezulu, ukuncibilika kwamanzi okukulo kuyehla, ngakho-ke umswakama oweqile wehlukaniswa ngendlela yamabhamuza. Njengoba isondela ngaphezulu, kukhishwa uketshezi oluthe xaxa, ngaleyo ndlela kwandise isilinganiso segesi-magma esiteshini. Lapho umthamo wamabhamuza ufinyelela emaphesentini angama-75, udaka luhlehla lube ama-pyroclast (izingcezu ezincibilikisiwe kancane futhi eziqinile) bese liqhuma.
Inqubo yesithathu ebangela ukuqhuma kwentaba-mlilo ukuvela kwe-magma entsha egumbini esivele ligcwele udaka lwento efanayo noma ehlukile. Lokhu kuhlangana kubangela ukuthi amanye amadaka asekamelweni anyuse ishaneli aqhume phezulu.
Yize izazi zentaba-mlilo zizazi kahle lezi zinqubo ezintathu, azikakwazi ukubikezela ukuqhuma kwentaba-mlilo. Kepha benze inqubekela phambili ebonakalayo ekubikezeleni. Iphakamisa isimo kanye nesikhathi sokuqhuma kwentaba-mlilo elawulwayo. Uhlobo lokugeleza kwelava lususelwa ekuhlaziyweni kwangaphambi komlando nomlando wentaba-mlilo ebhekwayo nemikhiqizo yayo. Isibonelo, intaba-mlilo ekhipha umlotha ngobudlova nodaka lwentaba-mlilo (noma ama-lahar) kungenzeka ukuthi yenze okufanayo ngokuzayo.
Ukunquma isikhathi sokuqhuma
Isikhathi sokuqhuma kwentaba-mlilo elawulwayo sincike esilinganisweni semingcele ethile, kufaka phakathi, kepha kungagcini lapho:
- umsebenzi wokuzamazama komhlaba entabeni (ikakhulukazi ukujula nokuvama kokuzamazama komhlaba kwentaba-mlilo);
- ukukhubazeka kwenhlabathi (kunqunywa kusetshenziswa ukuthambeka kanye / noma i-GPS kanye ne-interferometry yesathelayithi);
- ukukhishwa kwegesi (isampuli yenani legesi yesulfure dioxide ekhishwa yi-spectrometer yokuhlanganisa noma i-COSPEC).
Isibonelo esihle kakhulu sokubikezela ngempumelelo senzeka ngo-1991. Izazi zentaba-mlilo ezivela e-US Geological Survey zabikezela ngokunembile ukuqhuma kweMount Pinatubo ngoJuni 15 ePhilippines, okwakuvumela ukukhishwa ngesikhathi esifanele kweClark AFB futhi kwasindisa izinkulungwane zabantu.
