YADDA TEKUN MAGMA ZAI IYA MAYAR DA HYDROGEN ZUWA RUWA
Ka yi tunanin Duniya a ƙuruciyarta bayan wani babban karo: tekun duniya baki ɗaya na narkakken dutse — tekun magma (magma ocean) — ƙarƙashin yanayi mai kauri da aka yi galibi da hydrogen. Ka haɗa hydrogen da ƙarfe oxide da ke ɗauke da ƙarin oxygen, sai hydrogen ya ɗauki oxygen ɗin ya zama ruwa. Shin hakan zai iya faruwa a ma’aunin duniya baki ɗaya, kuma da wane sauri? Tatsuya Yoshida, na Cibiyar Kimiyyar Duniya da Rayuwa (Earth-Life Science Institute) a Cibiyar Kimiyya ta Tokyo, da abokan aiki a Jami’ar Hokkaido, Jami’ar Tohoku da Cibiyar Ƙasa ta Fasahar Bayanai da Sadarwa ta Japan sun gina samfurin lissafi don su gano.
Ƙarfe da aka raba biyu a zurfi
A cikin tekun magma mai zurfi, a matsin ƙasan mantle, ƙarfe ferrous (FeO, atom ɗin oxygen ɗaya ga kowane atom ɗin ƙarfe) zai iya rarrabewa (disproportionate): yana rabuwa zuwa ƙarfe na ƙarfe da ƙarfe ferric (FeO₁.₅, atom ɗin oxygen ɗaya da rabi ga kowane atom ɗin ƙarfe), bisa ga 3 FeO → 2 FeO₁.₅ + Fe. Ƙarfen ƙarfe yana nutsewa zuwa tsakiya kuma juyawar zafi (convection) tana yaɗa ƙarfe ferric, tana barin narkakken dutsen, a cewar nazarce-nazarcen baya, kusan da haɗuwa da oxygen kamar mantle na yau. Da wane sauri zai yi aiki da hydrogen da ke sama, kuma me yanayin zai yi wa magma a martani? Samfuran lissafi da yawa na baya sun ɗauki mantle da magma a matsayin tushen oxygen mara ƙarewa.
Fata da ke ci gaba da nutsewa
Samfurin yana haɗa shigar hydrogen cikin narkakken dutsen, aikinsa da ƙarfe ferric (H₂ + 2 FeO₁.₅ → H₂O + 2 FeO), raba ruwa da oxide tsakanin iska, magma da mantle mai ƙarfi da ke daskarewa a ƙasa, da sanyayar duniyar. Iskar tana farawa da kusan ƙwayoyin hydrogen goma ga kowace ƙwayar ruwa. Ana ƙirga adadi da N_TO: N_TO ɗaya daidai yake da adadin ƙwayoyin hydrogen da ya yi daidai da yawan ƙwayoyin ruwa a tekuna na yau. Ba a san yadda magma da mantle mai ƙarfi ke haɗuwa ba, don haka ƙungiyar ta gudanar da iyakoki biyu: musaya ba tare da shamaki ba (Case 1), ko narkakken dutse da aka kama cikin mantle yayin da yake daskarewa (Case 2).
Matsewar tana saman magma. Hydrogen yana yaɗuwa ta cikin narkakken dutse a hankali ƙwarai, don haka dole ya tsallaka siririn layin iyaka (boundary layer) a saman. Wannan layin ba ya tsayawa wuri ɗaya: idan aka sanyaya shi daga sama, yana ƙara nauyi har sai ya nutse kuma sabon narkakken dutse ya maye gurbinsa. Ga tekun magma mai zafi da zurfi — zafin saman kelvin 2,400, matsin gigapascal 50 a ƙasansa, watt 400 na zafi da ke fita ta kowane murabba’in mita — hakan yana faruwa kusan kowane daƙiƙa 70.
A wannan lokacin, hydrogen yana kai ƙasa da milimita ɗaya cikin layi mai kaurin milimita 19. Amma sabuntawa ba tare da tsayawa ba yana sa gangaren hydrogen ya kasance mai tsauri, don haka shigarsa tana kasancewa mai yawa: sama da N_TO 0.1 a kowace shekara dubu, 0.35 a matsakaici.
Samfurin: hydrogen yana yaɗuwa daga yanayi zuwa cikin siririn layin iyaka, yana aiki da ƙarfe ferric don samar da ruwa, kuma layin yana juyewa cikin tekun magma. A can ƙasa, ƙarfe yana rabuwa zuwa ƙarfe ferric da ƙarfe na ƙarfe. Case 1 da Case 2 sun bambanta a yadda magma ke musayar abu da mantle mai ƙarfi. — Hoto na 1, Yoshida et al. (2026), arXiv:2610.38503.
Kusan shekaru dubu goma
A babban misalin — N_TO 10 na hydrogen da ruwa gaba ɗaya, magma da ta kai har gigapascal 50 — ana cinye ƙarfe ferric, amma ƙarfe yana ci gaba da rabuwa a ƙasan tekun magma kuma yana maye gurbinsa, don haka narkakken dutsen yana kasancewa kusan da haɗuwa da oxygen iri ɗaya. Saman yana kaiwa ga daidaiton sinadarai da iska da zarar iskar ta ɗauki tururin ruwa kusan daidai da hydrogen: bayan kusan shekaru miliyan 0.01, wato shekaru 10,000. A lokacin, hydrogen, idan aka haɗa na iska da na magma, ya sauka daga kusan N_TO 5 zuwa ƙasa da 1, kuma ruwa, wanda galibinsa ke narke a cikin narkakken dutsen, ya kusan ninku biyu. Marubutan suna samun wannan sauri idan tekun magma yana da zurfi da zafi har ya kai cikin ƙasan mantle.
Daga nan tekun magma yana daskarewa cikin kusan shekaru miliyan 2 a Case 1, ƙarƙashin yanayin da ke aiki kamar bargo. Ruwa yana fita daga narkakken dutsen yayin da yake daskarewa zuwa lu’ulu’u: a Case 1, fiye da kashi 80% daga ciki yana ƙarewa a cikin iska.
Sama: matsin hydrogen (kore) da tururin ruwa (shuɗi) a cikin yanayi. Ƙasa: jimillar adadi, a N_TO. Hagu, Case 1; dama, Case 2. Kusa da shekaru miliyan 10⁻², hydrogen yana rugujewa kuma ruwa yana hawa. — Hoto na 6 (sassa a–d), Yoshida et al. (2026), arXiv:2610.38503.
Iska tana mayar da martani
Yayin da lu’ulu’u ke samuwa, suna ɗaukar ƙarfe ferric ba daidai ba. A Case 1, yana fifita mantle mai ƙarfi kuma narkakken dutsen zai karkata zuwa rage oxygen (reducing); ruwan da ke barin magma sai ya yi aiki da ƙarfe ferrous, kuma iskar tana ƙara wa magma oxygen. A Case 2, ƙarfe ferric yana taruwa a cikin narkakken dutsen da zarar saman mantle, wato sashensa mafi ƙarancin zurfi, ya daskare; daga nan hydrogen yana rage shi. Yanayin yana aiki a matsayin mai daidaitawa (buffer), kuma dukan yanayin biyu suna ƙarewa da iska mai kama da juna gaba ɗaya. Idan aka kashe wannan lissafin oxygen, kamar yadda samfuran baya suka yi, sai su rabu sosai.
Tekuna masu zurfi, ƙarin ruwa
A dukan gudanarwar, zurfin tekun magma, yawan ruwan da yake samarwa: matsi mafi girma yana fifita rabuwar ƙarfe. Ga zurfafan da ke cikin zangon da aka fahimta daga yadda abubuwan da ke son ƙarfe suka rabu tsakanin ƙarfe da dutse — gigapascal 28 zuwa 53 a ƙasa — fiye da kashi 70% na hydrogen yana ƙarewa a matsayin ruwa. Idan Duniya a ƙuruciyarta ta tara hydrogen daidai da ruwan da dukan Duniya a wajen tsakiyarta ke riƙe da shi a yau, N_TO 1 zuwa 10, wannan ilimin sinadarai zai iya bayyana adadin ruwan Duniya, marubutan sun rubuta.
Mars ta dace da wannan yanayi. Tekun magma na Mars, idan akwai shi, ba zai iya zurfafa fiye da tsakiyar duniyar ba, a gigapascal 18 zuwa 19, kuma samfurin sai ya ba da mantle da ba shi da haɗuwa da oxygen sosai kamar na Duniya — wanda ya dace da duwatsun sararin samaniya (meteorites) na Mars, waɗanda ilimin sinadaransu ke kusa da wurin da ƙarfe na ƙarfe da ƙarfe oxide ke zama tare.
Abin da zai iya canza hoton
Samfurin yana ɗaukar cewa ɗigon ƙarfe suna faɗawa tsakiya nan take; idan juyawar zafi ta riƙe su a rataye, za su iya barin saman yana rage oxygen kuma su iyakance samar da ruwa. Gwaje-gwajen matsi mai yawa ba su yarda kan yawan ƙarfe ferric da ke samuwa ba. Bayanan yaɗuwa suna tsayawa kusa da kelvin 1,700 kuma saurin aikin sinadarai ya fito ne daga ƙarfe oxide masu ƙarfi, don haka mai yiwuwa an raina shan hydrogen. Kuma samfurin yana barin mantle da rabon ƙarfe ferric zuwa ferrous na 0.06 zuwa 0.15, sama da 0.02 zuwa 0.06 na yau: hanyoyin daga baya, kamar zuwan abu mai yawan ƙarfe a makare, dole su saukar da shi.
Sararin da ya ci gaba da cika da hydrogen
Da zarar tekun magma ya daskare, tururin ruwan ya kamata ya taru ya zama teku a saman. Ragowar hydrogen zai ci gaba da kasancewa a cikin iska tare da gas na carbon da nitrogen; marubutan suna ba da shawarar cewa zai iya taimakawa wajen samar da methane, ammonia, sannan sinadarai na halitta (organic compounds) da wataƙila suka taru a cikin wannan teku na farko. Babban ɓangaren ruwan wannan teku, a cikin wannan hoto, ya fara ne a matsayin hydrogen a sararin sama, da aka jawo cikin magma ta wata fata da ke nutsewa tana sabunta kanta kusan kowane minti ɗaya.