Kudera lakutali, kusakanikirana kwa njira za geophysical kumazindikiritsa kusamutsidwa kwa magma pansi pa nyanja ngati chifukwa.
Ngakhale m'mphepete mwa nyanja ya Antarctica, mapiri amatha kupezeka. Kutsatizana kwa zivomezi zopitilira 85,000 kudalembedwa mu 2020 paphiri lamadzi la Orca, lomwe lakhala likulephera kwa nthawi yayitali, chivomezi chomwe chidafika pamlingo womwe sunawonekere m'derali. Mfundo yakuti zochitika zoterezi zikhoza kuwerengedwa ndikufotokozedwa mwatsatanetsatane ngakhale m'madera akutali, choncho madera osagwiritsidwa ntchito bwino, tsopano akuwonetsedwa ndi kafukufuku wa gulu lapadziko lonse lofalitsidwa m'magaziniyi. Communications Earth ndi chilengedwe.
Ofufuza ochokera ku Germany, Italy, Poland, ndi United States adachita nawo kafukufukuyu, yemwe adatsogoleredwa ndi Simone Cesca wa German Research Center for Geosciences (GFZ) Potsdam. Iwo adatha kuphatikizira njira za seismological, geodetic, ndi zowonera zakutali kuti adziwe momwe kusamutsidwa mwachangu kwa magma kuchokera pachovala cha Dziko Lapansi pafupi ndi malire a kutumphuka mpaka kumtunda komwe kunayambitsa chivomezicho.
Kuphulika kwa Orca pakati pa nsonga ya South America ndi Antarctica
Zivomezi zambiri zimachitika makamaka m'madera omwe kuphulika kuphulika. Chifukwa chake, kusuntha kwamadzi m'nthaka ya Dziko lapansi ndiko kukukayikira. Orca Seamount ndi chiwombankhanga chachikulu chotchinga pansi pamadzi chokhala ndi kutalika pafupifupi 900 metres kuchokera pansi panyanja komanso m'munsi mwake pafupifupi makilomita 11. Ili ku Bransfield Strait, njira yanyanja pakati pa Antarctic Peninsula ndi South Shetland Islands, kumwera chakumadzulo chakumwera chakumwera kwa Argentina.
“M’mbuyomu, zivomezi m’derali zinali zochepa. Komabe, mu Ogasiti 2020, zivomezi zamphamvu zidayamba kumeneko, ndipo zivomezi zopitilira 85,000 mkati mwa theka la chaka. Izi zikuimira chipwirikiti chachikulu kwambiri cha zivomezi chomwe chinalembedwapo,” anatero Simone Cesca, wasayansi mu Gawo 2.1 la Earthquake ndi Volcano Physics la GFZ komanso wolemba wamkulu wa kafukufuku wofalitsidwa tsopano. Panthawi imodzimodziyo, kusuntha kwapansi pamtunda wopitirira masentimita khumi ndi kukweza pang'ono kwa pafupifupi centimita imodzi kunalembedwa pa King George Island yoyandikana nayo.
Zovuta za kafukufuku kudera lakutali
Cesca anaphunzira zochitikazi ndi anzake ochokera ku National Institute of Oceanography ndi Applied Geophysics - OGS ndi University of Bologna (Italy), Polish Academy of Sciences, Leibniz University Hannover, German Aerospace Center (DLR) ndi University of Potsdam. Vuto linali loti kudera lakutali kuli zida zochepa za seismological, zomwe ndi masiteshoni awiri okha a seismic ndi awiri a GNSS (masiteshoni apansi a Gonyansa Nkuvomereza Satellite System yomwe imayesa kusamuka kwapansi). Pofuna kukonzanso nthawi ndi chitukuko cha chipwirikiticho komanso kuti adziwe chomwe chinayambitsa, gululo lidasanthulanso zambiri kuchokera kumalo otalikirapo a seismic ndi deta kuchokera ku ma satelayiti a InSAR, omwe amagwiritsa ntchito radar interferometry kuyesa kusuntha kwapansi. Chinthu chofunika kwambiri chinali kufotokozera zochitikazo ndi njira zingapo za geophysical kuti athe kutanthauzira deta molondola.
Kukonzanso zochitika za seismic
Ofufuzawa adawonetsa kuyambika kwa zipolowezo mpaka pa 10 Ogasiti 2020 ndikuwonjezera mndandanda woyambirira wa zivomezi zapadziko lonse lapansi, zomwe zili ndi zivomezi 128 zokha, kuzinthu zopitilira 85,000. Gululi lidachita zivomezi ziwiri zazikulu pa 2 Okutobala (Mw 5.9) ndi 6 Novembara (Mw 6.0) 2020 zisanathe. Pofika mu February 2021, zochitika za zivomezi zidatsika kwambiri.
Asayansi amazindikira kulowerera kwa magma, kusamuka kwa magma okulirapo, chifukwa chachikulu cha chivomezicho, chifukwa njira za zivomezi zokha sizingathe kufotokozera kusinthika kwamphamvu kwapadziko lapansi pa King George Island. Kukhalapo kwa kulowetsedwa kwa volumetric magma kungatsimikizidwe paokha pamaziko a deta ya geodetic.
Kuyambira pomwe adayambira, zivomezi zidayamba kusamukira m'mwamba kenako motsatana: zivomezi zakuya, zosanjikana zimatanthauzidwa ngati kuyankha kwa kufalikira kwa magma kuchokera pachitsime chakumtunda kapena kumalire a chobvala, pomwe zivomezi zosazama, zokulirakulira zimakulitsa NE-SW. idayambika pamwamba pa magma dike omwe amakula mozungulira, omwe amafika kutalika pafupifupi makilomita 20.
Chivomezicho chinachepa mwadzidzidzi pakati pa mwezi wa November, patatha pafupifupi miyezi itatu ya ntchito yokhazikika, polemberana ndi zochitika za zivomezi zazikulu kwambiri za mndandanda, ndi kukula kwa Mw 6.0. Mapeto a chiwombankhanga amatha kufotokozedwa ndi kutayika kwa kupanikizika mu magma dike, kutsagana ndi kutsetsereka kwa vuto lalikulu, ndipo kukhoza kuwonetsa nthawi ya kuphulika kwa nyanja yomwe, komabe, sikunatsimikizidwebe ndi deta ina.
Potengera deta ya GNSS ndi InSAR, asayansi adayerekeza kuti voliyumu ya Bransfield magmatic intrusion ili pamtunda wa 0.26-0.56 km³. Izi zimapangitsa kuti gawoli likhalenso chipwirikiti chachikulu kwambiri chomwe chinayang'aniridwa mu Antarctica.
Kutsiliza
Simone Cesca anamaliza ndi kunena kuti: “Kafukufuku wathu akuimira kufufuza kwatsopano kopambana kwa chipwirikiti cha zivomezi ndi chiphala chamoto kudera lakutali pa Dziko Lapansi, kumene kugwiritsiridwa ntchito pamodzi kwa zivomezi, geodesy, ndi njira zozindikira zakutali zimagwiritsiridwa ntchito kumvetsetsa mmene zivomezi zimayendera ndi kayendedwe ka magma popanda zida. madera. Ichi ndi chimodzi mwazinthu zochepa zomwe titha kugwiritsa ntchito zida za geophysical kuona kulowerera kwa magma kuchokera kumtunda wapamwamba kapena malire a kutumphuka kupita kumtunda wosaya - kusuntha mwachangu kwa magma kuchokera pachovala kupita kumtunda komwe kumatenga masiku ochepa. .”
Tanthauzo: "Chivomezi chachikulu choyendetsedwa ndi kulowerera kwamphamvu ku Bransfield Strait, Antarctica" ndi Simone Cesca, Monica Sugan, Łukasz Rudzinski, Sanaz Vajedian, Peter Niemz, Simon Plank, Gesa Petersen, Zhiguo Deng, Eleonora Rivalta, Alessandro Vuan, Plasencia Linares, Sebastian Heimann ndi Torsten Dahm, 11 April 2022, Communications Earth & Environment.
DOI: 10.1038/s43247-022-00418-5
