δD and δ18O variations of the magmatic system beneath Deception Island volcano (Antarctica): Implications for magma ascent and eruption forecasting
δD and δ18O variations of the magmatic system beneath Deception Island volcano (Antarctica): Implications for magma ascent and eruption forecasting
复制标题
欺骗岛火山（南极洲）下方岩浆系统的 δD 和 δ18O 变化：对岩浆上升和喷发预测的影响
DOI：
10.1016/j.chemgeo.2020.119595
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发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
Borrajo J.
中科院分区：
文献类型：
--
作者：
Alvarez-Valero A.M.;Gisbert G.;Aulinas M.;Geyer A.;Kereszturi G.;Polo-Sanchez A.;Nunez-Guerrero E.;Sumino H.;Borrajo J.
活火山挥发分的地球化学研究有助于深入了解岩浆演化和脱气等岩浆过程和演化，并可用于火山灾害评估。欺骗岛是南极洲最活跃的火山之一，在过去的两个世纪里记录了20多次爆炸性喷发。被困在欺骗岛岩石（玻璃和熔体夹杂物斑晶）的挥发物中的氢和氧同位素的变化提供了重要的信息，在这个火山套房的喷发历史的控制机制。因此，了解岩石学和相关的同位素变化，有可能预测未来喷发的可能发生及其主要喷发特征。本研究的新同位素结果结合详尽的岩石学知识揭示了欺骗岛（i）大多数岩浆快速上升和淬火，保留了喷发前岩浆的水含量和同位素比值信号，由于玻璃暴露于海水，以及大气和火山沃茨，再水化造成局部变化;（ii）随时间变化的管道系统，目前由封闭系统脱气主导，导致爆炸性喷发;（三）控制上升的岩浆与地表沃茨的相互作用，在欺骗岛和不同的岩浆停滞深度在进一步研究火山监测时可以考虑这些结果，以提高解释火山动荡期间记录的地球物理数据和信号的能力，从而预测火山爆发和有关灾害。
Geochemistry of volatiles in active volcanoes provides insights into the magmatic processes and evolution at depth, such as magma evolution and degassing, which can be implemented into volcanic hazards assessment. Deception Island is one of the most active volcanoes in Antarctica, with more than twenty explosive eruptions documented over the past two centuries. Hydrogen and oxygen isotopic variations in the volatiles trapped in the Deception Island rocks (glass and melt inclusions in phenocrysts) provide essential information on the mechanisms controlling the eruptive history in this volcanic suite. Thus, understanding the petrological and related isotopic variations in the island, has the potential to foresee the possible occurrence and its main eruptive features of a future eruption.The new isotopic results of this study combined with exhaustive petrologic knowledge reveal in Deception Island (i) fast ascent and quenching of most magmas, preserving pre-eruptive magmatic signal of water contents and isotopic ratios, with local modification by rehydration due to glass exposition to seawater, and by meteoric and fumarolic waters; (ii) a plumbing system(s) variable with time and currently dominated by closed-system degassing leading to explosive eruptions; (iii) control on the interactions of ascending magmas with the surface waters producing hydrovolcanic activity throughout the two main fault systems in Deception Island and at different magma stagnation depths. These results can be considered in further studies of volcanic monitoring to improve the capability to interpret geophysical data and signals recorded during volcanic unrest episodes, and hence, forecast volcanic eruptions and related hazards.