Kubura k’ubwato bujya hasi mu nyanja bwitwa Titan bwari bugiye gutemberera ibisigazwa bya Titanic kwateye kwibaza ibibazo ku byago biba biri mu bushakashatsi nk’ubwo hasi kure mu nyanja.
Igihe kimwe mu mpera za 1911, ikimanyu rutura cy’urubura cyavuye ku rubura runini cyane mu majyepfo ashyira uburengerazuba bwa Greenland. Mu mezi yakurikiyeho, icyo kimanyu cyagiye cyerekeza mu majyepfo, gishonga buhoro buhoro uko gitwarwa n’ibyerekezo by’amazi y’inyanja n’umuyaga.
Nuko, mu ijoro rikonje, ritarimo n’ukwezi tariki 14 Mata (4) 1912, urubura (iceberg) rw’uburebure bwa 125m nirwo rwari rusigaye ku rureshya na 500m rwamanyutse muri Greenland igizwe ahanini n’urubura rugongana n’ubwato bw’abagenzi bwa RMS Titanic bwari buvuye i Southampton mu Bwongereza bugiye i New York muri Amerika.
Mu masaha atageze kuri atatu, ubu bwato bwahise burohama, abantu 1,500 mu bari baburimo baratikira. Ibisigazwa by’ubu bwato ubu biryamye hasi mu ntera ya 3.8km mu gace kari muri 640km mu majyepfo ashyira uburasirazuba bw’umwaro wa Newfoundland wa Canada.
Icebergs, n’ubu ziracyateje akaga amato – mu 2019 izigera ku 1,515 zamanyutse mu gice cy’urubura cy’inyanja y’amajyaruguru ziramanuka zigera mu nzira z’amato hagati ya Werurwe (3) na Kanama (8). Gusa aho Titanic ishyinguye ho hafite ibyago byihariye, bivuze ko gusura ahari ibisigazwa bizwi cyane kurusha ibindi by’ubwato bisanzwe biteje akaga.
Muri uku kubura k’ubwato bwarimo abantu batanu b’abakerarugendo kandi bishyuye akayabo ngo bajye gusura ibisigazwa bya Titanic, BBC irareba aka karere k’inyanja uko kameze.
Kugendagenda ku ndiba y’inyanja
Hasi kure mu nyanja harijimye. Imirasire y’izuba vuba vuba imirwa n’amazi ntishobore kumanuka ngo irenge 1,000m uvuye hejuru ku buso. Urenze icyo gice, inyanja iba yijimye bikabije. Kubera iyo mpamvu Titanic iri mu gace kazwi nka “midnight zone” – ‘agace ka saa sita z’ijoro’ ugenekereje mu Kinyarwanda.
Ingendo zabanje zijya kuri ibyo bisigazwa zivuga ko kumanuka bimara amasaha arenga atatu mu mwijima ukabije mbere yo gutungurwa ukabona indiba y’inyanja imuritswe n’amatara y’ubwato buba buje gusura.
Mu kubona muri metero nkeya kubera urumuri rw’ubu bwato, kugenda ukagera muri ubwo bujyakuzimu ni umurimo ugoye, biba byoroshye cyane gutakarira aho ku ndiba y’inyanja.
Amashusho agaragara neza y’ibisigazwa bya Titanic yashyizwe hamwe nyuma y’ubushakashatsi bwo gukora scan bwamaze imyaka myinshi, agerageza gutanga ibimenyetso by’inzira ibigeraho. Ubuhanga bwo gukoresha amajwi buzwi nka ‘Sonar’ nabwo bufasha abari mu bwato kumva ibintu biri hasi byatuma bamenya aho berekeza hejuru y’urumuri ruto rutangwa n’amatara y’ubwato.
Abapilote b’ubwato bujya hasi nabo bagendera kuri tekinike izwi nka ‘inertial navigation’ ikoresha ubuhanga bwo kumenya aho bari n’aho berekeje bashingiye ku hantu bavuye.
Ikigo OceanGate nyiri ubu bwato Titan gifite ubu buhanga bwa ‘inertial navigation’ gifatanya n’ubwa Sonar mu kumenya ubujyakuzimu n’umuvuduko bagomba kugendaho ugereranyije n’aho indiba y’inyanja iri.
Nubwo hari ibi byose, abagenzi bagiye mbere gusura Titanic bajyanye n’amato ya OceanGate bagiye bavuga uburyo byabagoye kubona inzira mbere yo kugera ku ndiba y’inyanja.
Mike Reiss, wasuye ibisigazwa bya Titanic umwaka ushize mu bwato bwa OceanGate, yabwiye BBC ati: “Iyo mugeze hasi, ntimumenya mu by’ukuri aho muri. Twabanje kugendagenda aho hasi buhumyi tuzi gusa ko Titanic iri hafi aho, ariko ni mu mwijima ukabije kuburyo icyo kintu kinini cyane kiri aho hasi mu nyanja cyari muri 400m z’aho turi byadufashe iminota 90 tugishakisha.”
Microbes zirya ibyuma bya Titanic zirimo kwihutisha kwangirika kw’ibisigazwa byayo
Uko ikintu kimanuka hasi mu nyanja, niko ingufu (pressure) z’amazi agikikije ziyongera. Hasi ku ndiba y’inyanja muri 3,800m, Titanic n’ibindi biri hafi yayo byihanganira ingufu zikabakaba 40MPa (megapascal), izo ni inshuro 390 kurusha ingufu ziba ziri hejuru ku buso.
Robert Blasiak, umushakashatsi mu by’inyanja mu kigo Stockholm Resilience Centre cya Stockholm University yabwiye BBC ati: “Kugira ngo ubyumve neza, izo ni inshuro 200 z’ingufu z’umwuka uba uri mu ipine y’imodoka. Niyo mpamvu buriya bwato bujya hasi mu nyanja buba bufite inkuta nini z’ibyuma bikomeye cyane”.
Inkuta z’ubwato Titan zikoze mu byuma bya carbon-fibre na titanium zakozwe mu buryo nta kibazo zagira hasi muri 4,000m mu nyanja.
Imihengeri hasi mu nyanja
Dushobora kuba tumenyereye imihengeri ikomeye yo hejuru ishobora gutwara ubwato n’abantu boga bagata inzira, ariko hasi cyane mu nyanja naho haba bene iyo. Nubwo ubusanzwe iba idakomeye cyane nk’iyo tubona hejuru ku nyanja, iyo nayo ishobora gutuma ingano nini y’amazi igenda. Ishobora kuva ku miyaga yo hejuru ku buso igahungabanya amazi yo hasi bitewe n’ubushyuhe n’urwunyunyu rw’amazi ari hano cyangwa hariya, iyo mihengeri igera hasi izwi nka thermohaline.
Ibidasanzwe bizwi nk’inkubi za Benthic byo bishobora gutera imihengeri minini y’ingufu zikomeye ishobora gukubura ibintu biri hasi ku ndiba y’inyanja.
Abahanga bavuga ko bene iyi mihengeri yo hasi kure mu nyanja ishobora gusobanura impamvu mu gihe Titanic yacitsemo kabiri, hagati y’ibisigazwa byayo byombi hari intera irenga metero 500.
Igice kimwe cya Titanic bizwi ko kiryamye hafi y’ahantu hari ubukonje bukabije mu nyanja, hazwi nka Western Boundary. Imihengeri y’aho ituma haba imigina n’amabimba y’ibyondo aho hasi yatumye abahanga muri siyanse babona ingufu z’iyo mihengeri. Gusa byinshi babonye byagiye byirema aho hasi ku ndiba y’inyanja byakozwe n’imihengeri ifite imbaraga zigereranyije.
Gerhard Seiffert, inzobere mu bisigaratongo byo hasi mu nyanja wayoboye ubushakashatsi bwo gufotora (scan) Titanic mu mashusho aboneka neza (high resolution images), yabwiye BBC ko atabona ko imihengeri iri muri ako gace ishobora kugira icyo itwara bene buriya bwato bujyayo kubera ingufu nabwo buba bufite.
Yagize ati: “Ntabwo nzi imihengeri yateza ikibazo na bumwe muri ubu bwato bujya hasi mu nyanja aho Titanic iri. Iyo mihengeri […] nko mu bijyanye n’umushinga wacu twakoraga, yari ikibazo mu gukora ‘precision mapping’, ntiyari ikibazo ku mutekano”.
Ibisigazwa ubwabyo
Nyuma y’imyaka irenga 100 hasi mu nyanja, Titanic yagiye yangirika. Ubu bwato bukigonga Iceberg bugacikamo kabiri bwaramanutse bwihonda hasi ku ndiba y’inyanja, bihombanya ibice byabwo. Uko igihe gishira, za microbes zirya ibyuma zagiye zibumbira ku byuma bigize ubu bwato byihutisha kwangirika kwabwo.
Abahanga mu by’ukuri bavuga ko uko kwangirika kuvuye kuri za microbes na bacteria biri gutuma ubu bwato buri kwangirika vuba vuba ho imyaka 40 ku gihe cyari giteganyijwe.
Gerhard Seiffert ati: “Igisigazwa kigenda gishwanyuka buri gihe kubera ibyo byose. Buri mwaka utwara agace kawo gato. Gusa [iyo uhageze] iyo ugumye ahitaruye ntubukoreho, ntiwinjiremo ntacyo waba.”
Inkangu z’ibyondo
Nubwo hari ibyago bicye ko ibi bishoboka, inkangu n’ibirundo by’itaka bimeze nk’isuri itewe n’imihengeri bizwi ko bijya byangiza ibintu biri hasi ku nyanja, ndetse bizwi ko bijya bibamo ibintu bimwe byakozwe n’abantu biba byarajugunywe mu nyanja.
Ubu abahanga bamwe baribaza niba ibi ari kimwe mu byatuma ubu bwato kugeza ubu bwarabuze nubwo kugeza ubu nta kimenyetso ko ikintu nk’iki ari cyo cyatumye Titan ibura.
Uko imyaka yagiye ishira, abashakashatsi babonye ibimenyetso iruhande rw’aho Titanic iryamye ko yibasiwe n’inkangu nini cyane z’ibyondo zo hasi mu nyanja.
David Piper umuhanga n’umushakashatsi mu miterere y’ubutaka bwo hasi mu nyanja mu kigo Geological Survey of Canada wamaze imyaka myinshi yiga imiterere y’ubutaka iruhande rwa Titanic, avuga ko inkangu nini nk’izo zibaho rimwe mu myaka ibihumbi n’ibihumbi ariko ziba zikomeye.
Yaba Seiffert ndetse Piper bombi bavuga ko bisa n’ibidashoboka ko ibintu nk’ibi hari uruhare bifite mu kubura k’ubwato Titan.
Urebye kandi nta gace kari iruhande rwa Titanic katarigwaho n’abashakashatsi ku buryo hashobora kuba ibintu bitazwi n’abahanga.
Mu gusura Titanic mu minsi yashize ari mu bwato bwa OceanGate, Paul-Henry Nargeolet – umufaransa wahoze ari umuhanga mu gucubira no gutwara amato ajya hasi mu nyanja – yasuye agace kari amayobera yari yamenye akoresheje ubuhanga bwa Sonar mu 1996. Yaje gusanga aho hantu ari urutare rwuzuyeho ibimera byo mu nyanja.
Mu gihe gushakisha ubu bwato bwabuze bikomeje, hari ibimenyetso bicye cyane by’igishobora kuba mu by’ukuri cyarabubayeho bwo n’ababurimo. Gusa, ahantu nka hariya hagoye kandi hadatanga ikaze ibyago byo kuhasura ngo urebe ibisigazwa bya Titanic ni byinshi n’uyu munsi nk’uko byari bimeze mu 1986 ubwo abantu ba mbere bagezaga imboni yabo kuri ubu bwato kuva burohamye.
Gusa amatsiko ya muntu no gushaka kumenya atuma iteka hari abagerageza ingendo nk’izi nubwo bwose zaba ziteje akaga nk’aka aba bakererugendo babuze barimo.
@BBC
