Iby’ingenzi wamenya ku kirunga, umusozi -buhumekero bw’Isi

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Abatari bake bashoboye gutemberera mu burengerazuba bw’ U Rwanda bibonera uruhererakane rw’ibirunga  rufite uburebure bugera ku bilometero 80c. Byinshi kandi  abanyarwanda bazi ku birunga harimo n’iiruka ry’ ikirunga cya Nyiragongo na Nyamuragira byo muri Congo , amashyuza aherereye ku kiyaga cya Kivu ndetse n’amazuku babwiwe yo mu baturanyi bo mu gihugu cya Congo ahitana abadashishoza igihe batembera mu bice bivugwamo amazuku.

Virunga Today yifuje kubagezaho iby’ingenzi mwamenya kuri ibi iyi misozi duturiye, bityo amatsiko kuri iy’iyi misozi ifatwa nk’ubuhumekero bw’Isi akarangira burundu.

I.Ikirunga ni iki?

Ikirunga ni ahantu harangaye ku gice cy’inyuma cy’Isi ( Croute Terrestre) aho magma ( urusukume rw’ibitare rushonga mu nda y’isi),  gaz n’ivu byo mu nda y’isi bihingukira hanze.

II.Ikirunga kivuka gite?

Mu gice giherereye mu nda y’Isi cyitwa manteau na rimwe na rimwe mu gice cy’inyuma cy’Isi ( croute Terrestre), ibitare ( roche) birimo,  bigenda bibira, bishonga mu bice bimwe.   Ibisukika bita magma,   byikora igihe haba uku gushonga, iyi magma ikaba ifite  ireme rito ugereranije n’ibitare bitarashonga, ihita izamuka igana mu gice cyo hejuru werekeza ku butaka, ku Isi,  binyuze muri ibi bitare bitarashonga.

Muri iryo zamuka, iyi magma ishobora kwireka ahantu igakora icyo bita chambre magmatique: icyumba cya magma, ikaba yahamara ibisekuru n’ibisekuruza. Kugira ngo magma isohoke hanze ku butaka, nuko iyi magma isandarira ( fissure) mu bice bya  muri cya gipande cy’inyuma cy’isi , maze ikerekeza ku butaka inyuze mu muyoboro bita cheminee volcanique.

Ku Isi, iyi magma yigaragaza mu bisukika ( lave) no  ibice bikomeye ( bombes, scories, cendres, blocs).

Hanyuma ibi byakomotse kw’iruka, byirunda hamwe bigakora umusozi w’ikirunga.

III.Ibice bigize ikirunga

1. Chambre magmatique: Ni igice cyihindiramo, cyuzuramo magma giherereye mu ndiba y’ikirunga.
2. Cheminnee volcanique: Ni umuyoboro unyuramo magma yerekeza ku isi.
3. Cratere: Umunwa uherereye ku gasongero k’ikirunga aho magma, gaz n’ivu bisohokera.

IV.Ubwoko bw’iruka ry’ibirunga

Iruka-bucece (Eruption effusive): Isohoka ry’amahindure rikorwa buhoro buhoro ku buryo buhoraho kubera ko amahindure aba asukuma cyane ( tres fluides), agashobora no gutemba ku bice binini. Bene ubu bwoko bw’iruka bubyara ibirunga bigufi, bikozwe nk’ingabo kandi bifite ubutumburuke buto.

Iruka-riturika (eruption explosive) : Magma ijugunywa mu kirere n’imbaraga nyinshi, buri kanya, hakanyanyagizwa ivu n’ibindi bishingwe hirya no hino.

Magma aha ngaha iba ifashe cyane ( tres visqueux), bigatuma  iba icyibitsemo gaz nyinshi, ari nayo mpamvu iruka riherekezwa n’iturika rikomeye.

Iri ruka ribyara ubwoko bw’ibirunga byitwa strato-volcan

V.Ikirunga kikiruka, ikirunga gisinziriye, ikirunga cyazimye

Ikirunga kikiruka ( volcan actif)

Ni ikirunga kiruka cyangwa kikigaragaza ibimenyetso birimo  imitingito cyangwa isohoka rya za gaz. Ibi birunga bicyungirwa hafi n’abahanga muby’ibirunga kuko isaha n’isaha biba bishobora kuruka.

Abahanga mu by’ibirunga bemeza ko bavuga ko ikirunga kikruka iyo nibura cyigeze kuruka incuro 1 mu myaka ibihumbi icumi ishize.

Ikirunga gisinziriye

Ni ikirunga kitaruka ariko gishobora kuzaruka mu bihe biri imbere. Ibi birunga biba bikigaragaza ibimenyetso birimo imitingito y’Isi yoroheje  n’ibindi birimo nk’amazi ashyushye.

Ikirunga cyazimye

Nta bimenyetso kigaragaza by’iruka kandi haba hashyize imyaka myinshi kitaruka. Muri rusange ikirunga kirengeje imyaka ibihumbi 11 y’ubuvuke, ntigishobora kongera kuruka.

VI.Ese birashoboka kumenya ko ikirunga kigiye kuruka

Ikirunga kigiye kuruka kigaragaza ibimenyetso harimo:

1.Imitingito y’isi: Haba ubwiyongere mu bwinshi no mu bukana bw’imitingito y’isi hafi y’ibice byegereye ikirunga, ikimenyetso ko magma irimo izamuka yerekeza ku Isi.

2. Guhinduka ku butaka: Ubutaka bwegereye ikirunga bushobora guhinduka mu miterere bugakunjama ( se deformer) cyangwa bugatumba kubera imbaraga za magma izamuka. Iyi mihindagurikire ishobora kumenyekana hifashishijwe ibikoresho birimo GPS.

3.Izamuka n’ikwirakwira rya za gaz: Mu gace kegereye ikirunga haba ubwiyongere bw’imyuka irimo  nka dioxyde de soufre ( SO2, dioxyde de carbone ( CO2) ndetse na Sulfure d’hydrogene ( H2S). Ubu bwiyongere bukaba bugaragaza ko magma iri hafi kugera ku Isi.

4.Ukwiyongera k’ubushyuhe

Haba ubwiyongere bw’ubushyuhe kubutaka  bwegereye ikirunga, ikigaragaza ko magma irimo gushyushya no gushongesha ibitare byegereye ikirunga.

5.Ihinduka mu masoko ashyushye ari hafi y’ibirunga

Aya masoko ( eau chaude) azamura ikigero cy’ubushyuhe.

6.Urusaku rudasanzwe:

Ni urusaku rudasanzwe rwumvikana mu bisa a n’ibiturika cyangwa ibyiyasa nk’inkuba cyangwa ibisa n’ibivugiriza, byumvikana hafi y’ikirunga

VII.Aho ibirunga biboneka ku Isi

Ibirunga biboneka mu bice bitandukanye by’Isi, ariko aho biboneka cyane ni aho ibipande bigize isi bita plaques tectoniques bihurira. Dore bimwe mu bice bizwi kugira ibirunga byinshi

3. Ceinture de feu du Pacifique: Niko gace kabonekamo ibirunga byinshi ku Isi. Harimo ibirunga byo muri Andes , Japon, Filipine , Nouvele Zelande n’iigice cy’iburengerazuba bw’Amarika y’Amajyaruguru.
4. Méditerranée : Aka gace kagizwe n’ibirunga birimo icyitwa Vesuve cyo mu Butaiyani n’icyitwa Santorin cyo mu Bugereke.
5. Afrique de l’Est: La vallée du Rift, ni igice kiva mu ihembe ry’Afrika kikagera muri Mozambike, hakaboneka ibirunga birimi Kilimandjaro na Nyiragongo, Kalisimbi, Muhabura,…

VIII.Uturere tw’ibirunga

Uturere twegereye ibirunga tugira imiterere yihariye y’imisozi, ibibaya bihegereye bikadutandukanya  n’utundi duce.

Ikirunga: Ni umusozi uba warabyawe no kwirunda hamwe k’amahindure n’ivu biba byarutswe.

Ubutaka bw’amakoro: Ni imirima y’amahindure aba yarahindutse itaka ryiza riberanye n’ubuhinzi, iboneka hafi y’ikirunga.

Caldeira

Igice cyo hejuru cy’ikirunga gishobora gutengukira , gusenyukira mu kirunga rwagati ( effondrement) habaye iruka rikomeye maze kikarema ahantu hagari. Ibi bibaho iyo cya cyumba cya magma gisigayemo ubusa, umwanya iyi magma yari ririmo ugasenyukiramo cya gice cyo hejuru cy’ikirunga.

Caldeira ishobora kugira ubuso bunini, ikaba yagira umurambararo w’ibinyacumi by’ibilometero, kuri ubu buso hakaba hashobora kuba ibiyaga, amashyamba cyangwa umujyi nya mujyi.

Cratere

Igira ubagri buto ugereranije na caldeira ni ukuuga  ibinyajana bya metero z’umurambararo. ZIboneka ku gasongero k’ibirunga kandi zishobora kubamo ibiyaga bito igihe amazi abyihindiyemo. abyihindiyemo

 

Cratere secondaire

Iboneka hafi ya cratere nkuru cyangwa ikaboneka kure ku mabanga y’ikirunga. Ibaho kubera iruka riherekeza iruka nyirizina ( eruption secondaire) cyangwa irindi turika ryabera mu bindi bice by’ikirunga. Magma kandi sihobora gushaka ahandi yasohokera mu bindi bice by’ikirunga.

Fumerolles

Ni ahantu hasohoka gaz na vapeur d’eau bisohoka mu butaka, hafi ya cratere  cyangwa se hafi ya caldeira

Geysers, amashyuza

Geysers zohereza mu kirere amazi ashyushye na vapeur d’eau naho amashyuza ni ibidendezi  by’amazi ashyushye biboneka mu turere twegereye ibirunga

Ubuvumo

Ni ibinogo bikorwa n’amahindure atemba,  uko aya mahindure  agenda akomera ( se solidifier) mu gice cyo hejuru, ari nako akomeza gutemba mu gice cyo hasi, asiga imyanya irimo ubusa

IX.Ibyiza ku turere tubonekamo ibirunga

1. Ubutaka burumbuka buberanye n’ubuhinzi: Ivu rikomoka ku iruka ry’ibirunga rikize ku myunyu y’ingenzi ku buhinzi, igituma ubutaka bw’amakoro burumbuka bukaba buberanye n’ibikorwa by’ubuhinzi.

2. Géothermie : Ubushyuhe bukomoka ku iruka ry’ibirunga,  bushobora kubyazwa ingufu, ingufu zo mu bwoko bwisubira ( enerrgie renouveable) zitangiza ibidukikije.

3. Ubukerarugendo : Uturere tw’ibirunga , ku bw’iyo misozi y’ibirunga, za geysers, amashyuza,…. bikurura ba mukerarugendo, ibyatuma ubukungu bw’ibihugu bibarizwamo ibirunga buzamuka.

4. Amabuye y’agaciro : Mu turere twegereye ibirunga hashobora kuboneka ibirombe by’amabuye y’agaciro nka zahabu, argent, , ubutare…
5. Urusobe rw’ibinyabuzima :  Mu nkengero z’ibirunga no ku birunga haboneka ibimera n’inyamaswa byihariye ibituma habaho urusobe rw’ibinyabuzima.

X.Ibyago byaterwa no guturana n’ibirunga

Ibirunga bishobora gukurira ibyago ababituriye cyane cyane mu gihe cy’iruka ryabyo aho bishobora kwangiza byinshi kandi mu gihe gito. Dore ibyago by’ingezni ibirunga bishobora gukururira ababituriye:

1. Iruka riturika (Éruptions explosives) : Isandara, iturika ry’ikirunga ryohereza ibirimo ivu, ibitare  na za gaz kure mu biometero n’ibilometero uvuye ahi iruka ryakorewe. Iryo turika rishobora kwangiza bikomeye uduce twegereye ikirunga hakaba hagira n’abahatakariza ubuzima.

2.Umuvu w’amahindure ( Coulées de lave) : Amahindure ava mu kirunga yangiza ibyo ahuye nabyo byose , harimo inyubako zituwemo, ibikorwaremezo n’ibihingwa by’ubwoko bwose.

3. Umuvu w’inkekwe wa gaz,ivu n’ibitare (Coulées pyroclastiques) : Ni uruvange rugurumana  rwa gaz , ivu n’ibitare bunyura mu mabanga y’ikirunga ku muvuduko wo hejuru igihe kiruka. Ibi bishobora kwangiza byinshi kubera ubushyuhe n’umuvuduko wo hejuru biba bifite.

5. Lahars : Uruvange rw’ivu n’ibindi byarutswe n’ikirunga bikora icyondo igihe haguye imvura . Ibi bishobora gusenya uduce twegereye ibirunga ndeste n’ibikorwaremezo byinshi bikahangirikira.

6. Gaz volcaniques : Ni gaz z’uburozi nka  dioxyde de soufre na  dioxyde de carbone  zishobora gusohoka mu kirunga  zikaba zakwica abantu cyangwa inyamaswa ( amazuku).

Twifashishije: www.nationalgeographic.fr

Umwanditsi: Musengimana Emmanuel