Izinhlobo Zokuqhuma Kwezintaba-mlilo Nezimpawu Zazo
Izintaba-mlilo zingenye yezinto zemvelo ezishintshashintshayo kakhulu eMhlabeni. Ngaphansi kwezinhlobo zazo ezinhle, izintaba-mlilo zigcina amandla amakhulu angakhishwa nganoma yisiphi isikhathi ngokuqhuma. Ukuqhuma kwenzeka lapho i-magma evela ngaphansi kobuso ikhuphuka ngenxa yokucindezela kwegesi kanye nokwehluka kobuningi, bese iqhuma njenge-lava, umlotha, idwala elikhanyayo, noma igesi yentaba-mlilo. Ngokuthakazelisayo, ukuqhuma kuyahlukahluka kakhulu. Ezinye "zithule" futhi zigeleza njenge-lava, kanti ezinye ziqhuma kakhulu, zikhipha izinsika zomlotha phezulu emoyeni. Lokhu kwehluka kudala ukuhlukaniswa kwezinhlobo zokuqhuma, ngayinye inezici zayo, izimbangela, kanye nezinsongo zayo.
Ngokuvamile, uhlobo lokuqhuma luthonywa ukujiya kwe-magma, okuqukethwe yigesi, ukwakheka kwamakhemikhali (isb., i-basaltic, i-andesitic, i-rhyolitic), kanye nesimo somsele we-magma. Uma i-magma ijiyile, kuba nzima kakhulu ukuthi igesi iphume, okuvumela ingcindezi ukuthi yakheke futhi ibangele ukuqhuma. Ngokuphambene nalokho, i-magma encane ivame ukuvumela igesi ukuthi iphume kalula, okwenza ukuqhuma kube lula (ukugeleza) kunokuqhumisa (ukuqhuma).
1. Ukuqhuma kwentaba-mlilo eHawaii
Ukuqhuma kohlobo lwaseHawaii kwaziwa ngokuthi ukuqhuma okuthule okune-effusive. I-magma ngokuvamile i-basaltic, igeleza amanzi, futhi iyashisa, okuvumela i-lava ukuthi igeleze amabanga amade kalula. Izici eziphawulekayo zifaka phakathi imithombo ye-lava kanye nokugeleza kwe-lava okwakha imifula ye-lava emithambekeni.
Izici eziyinhloko:
– I-lava ewuketshezi kakhulu, elawulwa ukugeleza kwe-lava ende.
– Ukuqhuma okuncane noma cishe akukho nhlobo.
– Izinto ezi-pyroclastic (umlotha, i-lapilli) ngokuvamile aziningi.
– Yakha intaba-mlilo yesivikelo enemithambeka ethambile.
Imiphumela kanye nezingozi:
Ingozi enkulu ukugeleza kwe-lava, okungalimaza izindawo zokuhlala, umhlaba kanye nengqalasizinda. Nakuba kuvame ukunikeza isikhathi eside sokuphuma kuneziqhumane eziqhumayo, ukugeleza kwe-lava kuhlala kuyingozi uma indlela yabo ivinjiwe izindawo zokuhlala.
2. Ukuqhuma kweStrombolian
Uhlobo lweStrombolian lubonakala ngokuqhuma okuvamile okukhipha amabhomu entaba-mlilo, i-lapilli, kanye nomlotha othile. Lokhu kuqhuma kwenzeka lapho amabhamuza amakhulu egesi (ama-gas slugs) ephakama futhi eqhuma ebusweni be-crater. Aqhuma kakhulu kunokuqhuma kwaseHawaii, kodwa ngokuvamile anamandla aphakathi nendawo.
Izici eziyinhloko:
– Ukuqhuma okuvamile, hhayi okuqhubekayo.
– Kukhiqiza ukuqhuma kwamabhomu entaba-mlilo ashisayo.
– Ikholomu yokuqhuma ngokuvamile ayiphakeme kakhulu.
– I-lava ingageleza, kodwa ayihlali inamandla.
Imiphumela kanye nezingozi:
Ingozi enkulu kakhulu ukukhishwa kwamatshe akhanyayo azungeze i-crater, okungabangela imililo nokulahlekelwa yimpilo kwabakhuphuka izintaba noma izakhamuzi eziseduze ne-crater. Umlotha ungaba khona, kodwa ngokuvamile awubi mkhulu njengalapho kuqhuma ukuqhuma okukhulu.
3. Ukuqhuma kweVulcanian
Ukuqhuma kweVulcanian kuqhuma kakhulu futhi kuvame ukwenzeka nge-magma ejiyile (i-andesitic kuya ku-dacitic). Umsele we-magma ungavinjelwa yi-lava eqinile, egobile, okuvumela umfutho wegesi ukuthi wakheke. Lapho ukuvimba kuqhuma, ukuqhuma okunamandla kukhipha amatshe, umlotha ojiyile, bese kwakha ikholomu yokuqhuma engaphakama amakhilomitha amaningana.
Izici eziyinhloko:
– Ukuqhuma okufushane kodwa okunamandla, kungaphindaphindwa.
– Ikholomu yomlotha omnyama, ojiyile.
– Izinto eziningi ezi-pyroclastic: umlotha, i-lapilli, amabhlogo.
– Ngezinye izikhathi kuhambisana namagagasi okushaqeka.
Imiphumela kanye nezingozi:
Ukuwa komlotha okukhulu kungabangela izinkinga zokuphefumula, kulimaze izitshalo, kuphazamise ukuhamba kwezindiza, futhi kubhidlize uphahla uma luqongelela. Ukuwa kwamatshe amakhulu nakho kuyingozi ngaphakathi kwebanga elingamakhilomitha amaningana.
4. Ukuqhuma kwePlinian (Plinian/Vesuvian)
Ukuqhuma kwePlinian kuphakathi kwezinto ezinamandla kakhulu neziqhumayo. Kuqanjwe ngoPliny Omncane, owaqopha ukuqhuma kweNtaba iVesuvius ngo-79 AD. Lokhu kuqhuma kuvame ukuhlotshaniswa ne-magma e-viscous, ecebile nge-silica (dacitic-rhyolitic) enokuqukethwe okuphezulu kwegesi. Ngenxa yalokho, izinsika zokuqhuma zingaphakama amashumi amakhilomitha, zize zifinyelele ngisho nase-stratosphere.
Izici eziyinhloko:
– Ikholomu yokuqhuma iphakeme kakhulu futhi iyaqhubeka.
– Umlotha usakazeka kabanzi ngumoya, ungadlula izifundazwe ngisho namazwe.
– Kungadala ukugeleza kwe-pyroclastic uma ikholomu iwa.
– Ngokuvamile kubangela i-lava uma ixubene nemvula noma amanzi omfula.
Imiphumela kanye nezingozi:
Izingozi ziningi: ukuwa komlotha wesifunda, ukuphazamiseka kwezindiza, umonakalo kwezolimo, kanye nosongo lokugeleza kwe-pyroclastic okusheshayo nokushisayo kakhulu. Ukuqhuma kwe-Plinian kuvame ukubangela izinkinga zobuntu ngenxa yomthelela wazo omkhulu.
5. Ukuqhuma kwePelean (Pelean)
Uhlobo lwePelean lubhekisela ekuqhumeni okuhlanganisa ukwakheka kwe-lava dome evela ku-magma egobile kakhulu. Le dome ingawa nganoma yisiphi isikhathi, ikhiqize ukugeleza kwe-pyroclastic noma ifu elishisayo elihla ngokushesha esigodini. Igama elithi "Pelean" livela eNtabeni iPelée eMartinique, eyaqhuma ngo-1902.
Izici eziyinhloko:
– Idome elikhulu le-lava lakhiwa esicongweni/emgodini.
– Ukuwa kwedome kwabangela ifu elishisayo elibusayo.
– Amakholomu omlotha angenzeka, kodwa ngokuvamile awaphakeme njengalawo asePlinian.
– Imisebenzi ingahlala isikhathi eside (amasonto kuya ezinyangeni).
Imiphumela kanye nezingozi:
Amafu ashisayo ayisongo esikhulu: amazinga okushisa awo angafinyelela amakhulu ama-degree Celsius futhi isivinini sawo siphezulu kakhulu, okudinga ukususwa kusenesikhathi. Ngaphezu kwalokho, ukukhukhuleka kweqhwa kwezinto kungavimba imifula futhi kubangele ama-lahar.
6. Ukuqhuma kweSurtseyan (Surtseyan)
Ukuqhuma kwe-Surtseyan kwenzeka lapho i-magma ihlangana namanzi olwandle noma amanzi angajulile, okuholela ekuqhumeni kwe-phreatomagmatic (umphumela wokuxhumana kwe-magma namanzi). Lolu hlobo luqanjwe ngesiqhingi sase-Iceland i-Surtsey, esavela ekuqhumeni kwamanzi ngawo-1960.
Izici eziyinhloko:
– Ukuqhuma okubangelwa ukuthintana kwe-magma namanzi.
– Ikhiqiza umhwamuko wamanzi, umlotha omncane, kanye “nokuqhuma kwesisekelo” (ukuvunguza eceleni).
– Kungakha iziqhingi ezintsha noma ama-tuff rings.
– Umlotha uvame ukuba muhle ngoba i-magma ihlukene kakhulu.
Imiphumela kanye nezingozi:
Izingozi ezinkulu zifaka phakathi izinto ezikhishwayo, amagagasi okuqhuma kwemikhumbi eceleni, kanye nokuphazamiseka kwemikhumbi kanye nezindiza endaweni. Uma kwenzeka eduze nogu, imiphumela ingafinyelela ezindaweni zokuhlala ezisogwini.
7. Ukuqhuma Okushisayo
Ukuqhuma kwe-phreatic ukuqhuma okuqhutshwa umhwamuko wamanzi, kunokuba kukhishwe ngqo i-magma entsha. Amanzi angaphansi komhlaba noma amanzi angaphezulu ashiswa yidwala elishisayo aphenduka umusi ocindezelayo bese eqhuma, ekhipha umlotha, udaka, kanye nedwala elidala emngxunyeni womoya.
Izici eziyinhloko:
– Akuhlali kuhambisana ne-lava entsha noma i-magma.
– Ukuqhuma kungaba ngokuzumayo futhi kube nzima ukukubikezela.
– Izinto eziphumayo zivame ukuba sezingcezu zamatshe amadala.
– Izinsika zomusi nomlotha zingavela ngokuzumayo.
Imiphumela kanye nezingozi:
Ukuqhuma okukhulu kuyingozi ngoba kuvame ukwenzeka ngaphandle kwezimpawu ezisobala zentaba-mlilo futhi kungabangela ukulimala eduze kwentaba-mlilo. Ukuwa kwamatshe endawo kanye nokuwa komlotha kuyisongo esikhulu, ikakhulukazi kubavakashi kanye nabasebenzi endaweni ephezu kwentaba-mlilo.
Ukuqonda Izinhlobo Zokuqhekeka Kwezikhukhula Zokunciphisa Umonakalo
Ukuqaphela izinhlobo zokuqhuma kwezintaba-mlilo kungaphezu nje kolwazi lwezemfundo. Lolu lwazi lubalulekile ekunciphiseni izinhlekelele: ukunquma izindawo eziyingozi, izindlela zokuphuma kwabantu, kanye nokulungela umphakathi. Ukuqhuma kwezintaba-mlilo okufana nokwaseHawaii kudinga ukuqapha ukugeleza kwe-lava nokuvikela ingqalasizinda, kuyilapho ukuqhuma kwezintaba-mlilo okufana nePlinian noma iPelean kudinga ukususwa kwabantu ngokushesha ngenxa yosongo lokugeleza kwe-pyroclastic kanye nokuwa komlotha okusabalele. E-Indonesia, etholakala ePacific Ring of Fire, ukuqonda izici zokuqhuma kwezintaba-mlilo kubalulekile ekunciphiseni ingozi yokulahlekelwa ukuphila.
Ekugcineni, intaba-mlilo ngayinye inendlela yayo yokuqhuma, engashintsha ngokuhamba kwesikhathi, kuye ngezimo ze-magma yayo kanye nesimiso sentaba-mlilo. Ngakho-ke, ukuqapha yizikhungo zentaba-mlilo, ukunamathela ezincomweni zezindawo eziyingozi, kanye nemfundo yomphakathi kuyinhlanganisela engcono kakhulu yabantu yokuphila ngokuphepha nezintaba-mlilo.
