Elona thambeka likhulu emhlabeni, elaziwa ngokuba yi-A23a, liphinde laba ngumlinganiswa ophambili emva kwamashumi eminyaka evaleleke kulwandle lwaseMazantsi.. Obu bunzima bukhulu bomkhenkce, onommandla omalunga nendawo Iikhilomitha ezi-3.600 ezikwere kunye nobunzima obuqikelelwayo malunga ibhiliyoni yeetoni, sele iqalisile ukutyibilika, iqalisa uhambo olunokuphawula ukunyamalala kwayo ngokupheleleyo. Ukususela ekuzalweni kwayo okokuqala ngo-1986, le iceberg iye yajongwa kwaye yaphononongwa luluntu lwezenzululwazi lwamazwe ngamazwe, olunomdla walo ugxile ekuqondeni indlela yokuziphatha kunye nefuthe layo kwi-ikhosistim yolwandle.
Ngaphezulu kwamashumi amathathu eminyaka, i-A23a yahlala ixinga kuLwandle lwaseWeddell, ibanjwe yinto eyaziwa ngokuba yi "Taylor's Column," i-vortex engaphantsi kwamanzi eyayiyigcina ijikeleza endaweni.. Nangona kunjalo, kwiminyaka yakutshanje, le ice colossus ikwazile ukuzikhulula kwaye iqalise ukutsalwa emantla yimisinga yolwandle. Izazinzulu eziphuma kwiBritish Antarctic Survey (BAS) ziqinisekisile intshukumo yayo ngemifanekiso yesathelayithi, ephawula ukuqala kwenqanaba elitsha kwimbali yayo ende yokwakheka komhlaba.
Kutheni iphumile ngoku?
Ibutho le-A23a libangelwa yindibaniselwano yezinto zendalo kwaye mhlawumbi nempembelelo yokutshintsha kwemozulu. Ukusukela oko yahlukanayo neFilchner Ice Shelf e-Antarctica ngo-1986, le ntaba yomkhenkce igcine uzinzo olukhulu ngenxa yobukhulu bayo kunye nokusebenzisana kwayo namazantsi olwandle. Nangona kunjalo, ukuguquguquka kweemeko zolwandle kunye nemozulu, kunye nemozulu yendalo emiphethweni yalo, kube nendima ebalulekileyo ekukhutshweni kwayo kutshanje.
Ukufudumala kwehlabathi bekunokukhawulezisa le nkqubo, ekubeni ukunyuka kwamaqondo okushisa kummandla we-Antarctic kuchaphazela zombini umoya kunye namanzi, kunciphisa ukwakheka komkhenkce. Nangona kunjalo, ezinye izazinzulu zicebisa ukuba indlela ye-A23a inokuba yinxalenye yomjikelo wendalo wee-icebergs, ezithanda ukuqhawuka, zihambe ziye kumanzi ashushu, ziqhawuke zize ziphele nya.
Indlela eya ekwahlukaneni kwayo
I-A23a ilandela indlela eyaziwa ngokuba yi-“iceberg alley,” eqhutywa yi-Antarctic Circumpolar Current.. Olu hambo luzakukusa eMazantsi eAtlantiki kwaye mhlawumbi luya kukusondeza kufutshane ne Isiqithi esisezantsi kweGeorgia. Apho, i-iceberg iya kujongana namanzi afudumeleyo, aya kukhawulezisa ukuqhekeka kwawo abe ngamaqhekeza amancinci aya kuthi ekugqibeleni anyibilike ngokupheleleyo.
Le ntshukumo ayiqhelekanga kwi-icebergs calving esuka e-Antarctica, kodwa into eyenza i-A23a ibe yokhethekileyo bubukhulu bayo kunye nobudala bayo, nto leyo eyenza ukuba ibe luphononongo olukhethekileyo kubaphandi. Nangona indawo ekuyiwa kuyo iqinisekisiwe ngokwenyani, izazinzulu ziyaqhubeka nokubeka esweni umkhondo wayo kunye nemeko yokuyifumana idatha exabisekileyo malunga neenkqubo zendalo ezinxulumene nomjikelo wobomi wee-icebergs.
Impembelelo kwi-ikhosistim yolwandle
Iintaba zomkhenkce ezinkulu ezifana ne-A23a zidlala indima ebalulekileyo kwizinto eziphilayo zaselwandle. Njengoko ziqhekeka, ziyakhulula izondlo ezibalulekileyo kumanzi ajikelezileyo, ukukhuthaza ukukhula kwezinto ezincinci ezifana ne-phytoplankton, ezisebenza njengesiseko samakhonkco okutya amakhulu. ULaura Taylor, i-biogeochemist yeprojekthi I-BIOPOLE, yachaza ukuba ezi zondlo zinokuguqula iindawo ezingavelisi mveliso zibe ziindawo zokwenyani zobomi baselwandle.
Ukongeza, i-A23a iyaphononongwa ukuze kuqondwe ukuba ii-icebergs ziyichaphazela njani na imijikelo yekhabhoni yehlabathi kunye nezondlo. Iingcali zenzululwazi ziqokelela iisampulu zamanzi malunga ne-iceberg ukuhlalutya impembelelo yayo kwi-carbon balance phakathi kolwandle kunye nomoya, umba obalulekileyo wokujongana nokutshintsha kwemozulu.
Umngeni wokutshintsha kwemozulu
Imeko ye-A23a iphinda ibonise imiphumo yokutshintsha kwemozulu kummandla we-polar. Ngokweengxelo zamva nje ezivela kwi Umbutho weMeteorological weHlabathi, ngaphezu kwe-90% yeelwandlekazi zehlabathi ziye zafumana amaza obushushu kwiminyaka yakutshanje, nto leyo ebangela utshintsho olukhulu e-Antarctica. Ezi meko zinciphisa umkhenkce wolwandle kwaye zikhawulezisa ukunyibilika komkhenkce.
Nangona kunjalo, kusekho okuninzi okungaziwayo malunga nokuba utshintsho lwemozulu luzichaphazela njani na ii-icebergs ezinkulu ezifana ne-A23a. Izifundo ezifana nezo zenziwa yi UPhando lwaseBritane lweAntarctic Zibalulekile ukuqonda ezi nkqubo kunye nokuphuhlisa izicwangciso zokunciphisa iimpembelelo zabo kwinkqubo yemozulu yehlabathi kunye ne-ecosystems yendawo.
Ukuhamba kwe-A23a kubonisa ubungangamsha kunye nobuthathaka bendalo. Uhambo lwayo oluya ngasentla alubonisi kuphela isiphelo sesiqhwaga somkhenkce, kodwa kwakhona sivula ifestile ukuze sihlolisise indlela iinkqubo zendalo kunye nemozulu ezidibana ngayo kwi-polar oceans. Iinyanga ezizayo ziya kuba yimfuneko ukuze siqonde ngcono ifuthe lalo mcimbi kwi-ecosystem yaselwandle kunye nokuba zeziphi izifundo esinokuzifumana ukuze sijongane nemingeni yokutshintsha kwemozulu.