Mauna Loa, ikirunga kitarazima kirusha ibindi ubunini ku isi cyatandiye kuruka uhereye mu mwala wa 1984.
Amahindure yacyo atemba hasi iruhande rw’ikirunga afite ubushyuhe bwa dogere selisiyusi 1000 oC gusa abahanga mu bumenyi bw’isi bavuga ko abagituriye nta bwoba ibi bibatera.
Ubugari bwa Mauna Loa bungana bute ?
Mauna Loa ubundi bisobanura ngo “umusozi muremure” mu rurimi rw’Igihawai, ni cyo kirunga kinini kuruta ibindi byose ku isi. Kiri ku buso bwa kilometero kare 5.271 kikaba kiri ku ruhererekane rw’ibirunga bitanu bigize ikirwa kigari cya Hawaii.
Ubutumburuke bwa Mauna Loa buri ku birometero 4.170 uvuye ku nyanja ariko umusingi wacyo uba mu nsi y’inyanja. Kuva aho kugeza hejuru hari metero 9.170, bituma kiri hejuru kurusha Umusozi wa Everest.
Kuki Mauna Loa iruka ?
Maguma cyangwa ibikoma biruka n’ikirunga zagiye zicucunyuma munsi ya Mauna Loa n’ibindi birunga bituranyi byayo ziva “ahantu hari umuriro” hasi cyane mu nda y’Isi. “Nta we uzi mu by’ukuri impamvu hari iki gice cy’ubushyuhe” nk’uko bivugwa na Carmen Solana, inzobere mu bumenyi bw’ibirunga muri Kaminuza ya Portsmouth mu Bwongereza.
“Icyakora,” nk’uko Solana akomeza abivuga “bishobora kuba biterwa no kubora kw’ibice bitanga amashanyarazi biba mu ntimatima y’isi.” Yongeraho ko “Izi nkingi za maguma zabumbiye hamwe uruhererakane rw’Ibirwa bya Jawaii.”
Nk’uko Solana abisobanura, Mauna Loa iyo irutse, maguma ziturikira kuri caldera, umwobo usa n’ibakuri uherereye hejuru y’ikirunga. Yitwa Mokuaweoweo, ikaba agace k’ibirometero kare 15 ndetse n’ubujyakuzimu bwa metero 180.
Hanyuma rero maguma zisohoka ku “myenge” ku rutare, iruhande rw’ikirunga ubundi zigatembera mu nsi y’umusozi nk’ibisukika bizwi mu Cyongereza nka lava. Izi lava zigira ubushyuhe bungana na 1000o C kandi butwika ikintu cyose bwazitambika.
Mu gihe ikirunga kiruka, gisohora ibintu bihora hanyuma bikabumba ibice by’ibirahuri byitwa “imisatsi ya Pele.” “Pele ryahoze ari izina ry’imana y’ingore byatekerezwaga ko atuye muri Mauna Loa. Ibyo bice bifite ibara rya zahabu,” nk’uko Solana abivuga. Yongeraho ko “[Pele] yari [imana] y’inyamujinya.”
Ni kuki iruka rya Mauna Loa ari ikintu gikwiye kwitabwaho ?
Mauna Loa imaze kuruka inshuro 33 kuva mu 1843, ikaba ari itariki y’iruka ryayo rya mbere ryamenyekanye bikandikwa.
Mu kigereranyo, ni iruka riba buri nyuma y’imyaka itanu n’igice. Icyakora, iruka rya Mauna Loa riheruka ryabaye mu myaka hafi 40 ishize.
“Hagiye haba bimwe mu bimenyetso byo guturika kwa maguma mu myaka 10 ishize,” nk’uko Andrew Hooper, Porofeseri wa Geophysique muri Kaminuza ya Leeds mu Bwongereza abivuga, gusa ngo “nta ruka ry’ikirunga iryo ari ryo ryose riraba kugeza ubu.”
Iruka ry’ubu rya Mauna Loa riha abahanga mu bumenyi bo mu gisekuru gishya uburyo bwo kwiga uko icyo kirunga gikora,” nk’uko Porofesa Hooper abivuga.
Bitandukanye n’ibirunga byinshi, Mauna Loa ubusanzwe ntabwo iturika ngo isandare, nkuko ubundi ibindi birunga bigira bikazamura za lava zitumbagirana ikirere n’ivu ryinshi.
Ahubwo, za lava za Mauna Loa zitemba buhoro buhoro. “Ugutemba kwa kwa lava nta kibazo bitera ubuzima,” nkuko Prof Hooper abivuga, ngo “kuko ushobore kuzihunga.” “Na none kandi lava ziva mu kirunga ntizigenda zigana mu burengerazuba ngo zisatire imijyi ya hafi aho ahubwo zitemba zijya
Izi lava zikora urugendo rurerure zerekera aho mbere yo kwangiza cyane umutungo,” nkuko Hooper abivuga. Icyakora nubwo bimeze bityo, abaturiye aka gace bashobora kugirwaho ingaruka n’ibyuka bisohorwa na Mauna Loa.
Solana, mu cyongereza asobanura ko “imyuka isohorwa n’ikirunga irimo diyogiside ya silifire na klorine isohoka ifite ubukonje mu kirere butanga ‘vog’ na yo ikaba ari ibicu by’ikirunga.
Akomeza asobanura ko “ibi bishobora guteza ikibazo cyo kuribwa amaso ndetse n’ingorane mu guhumeka.” Abategetsi bashinzwe ubuzima muri Hawaii bavuga ko umwuka aho uguma ari mwiza uretse ko igihe icyo ari cyo cyose ushobora kwandura.
Biramutse ari byo, abaturiye aha hantu bagirwa inama yo kureka ibikorwa bakorera hanze ndetse no kuba mu nzu amadirishya n’imiryango bakabifunga.
Iradukunda Fidele Samson
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