iBolide Eyakhe Yankulu
Kwiminyaka eyi 2 bhiliyoni eyadlulayo, kwakungekho kwasityalo kule planethi, ubomi obabukhona ngeloxesha yayizintsholongwane kuphela. Kodwa nangona kwakunjalo, izinto zaba mbi mpela. iBolide eyakhe yankulu yabizeleka eMhlabeni. Kwaye yeza imbonzeleka. Ukuba ezintsholongwane zazineenyawo ngezacela kwabanentsente!Asiqinisekanga nokuba le bolide yayiluhlobo lwe asteroid (isiqhushumbisi esiqingqekileyo esililitye) okanye icomet (enomphakathi owenziwe ngamatye kutye nomkhenkce, olandelelwa ngumsila wegesi). Kwaye asiqinisekanga nangesantya eyayihamba ngaso, nangona kuqikelelwa ukuba yayihamba ngesantya esimalunga nama 20 ekhilomitha ngomzuzwana. Xa kujongwa ubungakhulu be crater eyathi yayidala, uqikelelo lomlinganiselo wayo uphakathi kwekhilomitha ezi 5 kunye ne 15 ububanzi. Konke oku kuxhomekeka kwisantya, ubunzima kunye necala eyathi yantlitheka ngalo. Oku kuthetha ukuba yayinkulu ukodlula iTable Mountain.
Yabetheka Ngamandla!
Njengokuba le bolide isondela, umhlaba wabamba umphefumlo…emva koko yabetheka ngamandla! Incam yoluntlitheko yayikufuphi nedolophi esele ibizwa nge Vredefort kulemihla, malunga ne 120 khilomitha ukuya kumzantsi-ntshona we Johannesburg. Iziphumo zaba ngumtyobo wengozi eyakhe yankulu.Yathi xa ibetheka, yakhupha amandla ombane alinganiswa ne megatons zesiqhushumbisi ezilinganiswa ne 100 yezigidi- Zi toni ezili 100 triliyoni lamandla ebhombo. Xa kuthelekiswa, eyona bhombo inamandla ye nuclear neyakhe yaqhushumbiswa yayinama 50 emegatons. Kwimizuzu nje embalwa, isibalo esingama 70 000 ecubic khilomitha soMhlaba safunquka sabhabha emoyeni, kwaqhuma uthuli olwafikelela kwi atmosphere lwathintela ukukhanya kwelanga.
Kwanetha imvuthuluka yamatye neyanwenwela kumakhulu-khulu ekhilomitha kunye nomoya owabhudla yonke indawo, uhamba ngezantya ezingama waka-waka ekhilomitha ngeyure. Icrater engaphezulu kwama 50 eekhilomita ubunzulu, yagrumbeka emhlabeni, umhlaba waphenduleleka.
Ngaphezu kwalo dulubhentsu, oluntlitheko lwabanga nokukekela kwemihlaba, iinyikima, ukuqhekeka kwamathumbu omhlaba kunye nezinye iingozi zendalo ezathwaxa iplanethi yonke.
iVredefort Dome
Amadonga omqengqelezi we crater yokuqala akhawuleza awa, kodwa endaweni yawo ke kwenzeka icrater engenzulu kuyaphi enobubanzi obumalunga nama 300 eekhilomitha. Amatye asesiphakathini aphakama ngethuba umhlaba ubuphantsi koxinzelelo uphinda ubuyela ngaphezulu. Wenza iqhuma elibukufana ne dome, nkqwa kanye naxa uxhumela epulini. I-Vredefort Dome yabe iyadaleka kanjalo. Iqela lemisele ejikelezileyo nayo yombeka.Akukholeleki ukuba zonke ezi ziganeko ziyimbali engalibalekiyo zenzeka kwimizuzu eli 15 emva kontlitheko lokuqala! Ukuba babukhona obunye ubomi eMhlabeni, ngaphandle kwee ntsholongwane, esi siganeko ngesaye senza ubhubhane wee ndidi ezininzi zendalo. Lilonke, kwaba kokona kuhlaselwa yi meteorite kwakhe kwabaku khulu – nesona siganeko senzeka kuqala sontlitheko. Akukabikho siganeko sele sibhaqiwe ukuzothi gaa ngoku.
Translated by Zizipho Silwana