Exceptional eruptive CO2 emissions from intra-plate alkaline magmatism in the Canary volcanic archipelago
2023
Mike Burton | Alessandro Aiuppa | Patrick Allard | María Asensio-Ramos | Ana Pardo Cofrades | Alessandro La Spina | Emma J. Nicholson | Vittorio Zanon | José Barrancos | Marcello Bitetto | Margaret Hartley | Jorge E. Romero | Emma Waters | Alex Stewart | Pedro A. Hernández | João Pedro Lages | Eleazar Padrón | Kieran Wood | Benjamin Esse | Catherine Hayer | Klaudia Cyrzan | Estelle F. Rose-Koga | Federica Schiavi | Luca D’Auria | Nemesio M. Pérez
Abstract Alkaline mafic magmas forming intra-plate oceanic islands are believed to be strongly enriched in CO2 due to low-degree partial melting of enriched mantle sources. However, until now, such CO2 enhancement has not been verified by measuring CO2 degassing during a subaerial eruption. Here, we provide evidence of highly CO2-rich gas emissions during the 86-day 2021 Tajogaite eruption of Cumbre Vieja volcano on La Palma Island, in the Canary archipelago. Our results reveal sustained high plume CO2/SO2 ratios, which, when combined with SO2 fluxes, melt inclusion volatile contents and magma production rates at explosive and effusive vents, imply a magmatic CO2 content of 4.5 ± 1.5 wt%. The amount of CO2 released during the 2021 eruptive activity was 28 ± 14 Mt CO2. Extrapolating to the volume of alkaline mafic magmas forming La Palma alone (estimated as 4000 km3 erupted over 11 Ma), we infer a maximum CO2 emission into the ocean and atmosphere of 1016 moles of CO2, equivalent to 20% of the eruptive CO2 emissions from a large igneous province eruption, suggesting that the formation of the Canary volcanic archipelago produced a CO2 emission of similar magnitude as a large igneous province.
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