Abstract 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.

中文翻译：

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欺骗岛火山（南极洲）下岩浆系统的 δD 和 δ18O 变化：对岩浆上升和喷发预测的影响

摘要 活火山中挥发物的地球化学有助于深入了解岩浆演化和脱气等深部岩浆过程和演化，可用于火山灾害评估。欺骗岛是南极洲最活跃的火山之一，在过去的两个世纪中记录了 20 多次爆发性喷发。被困在欺骗岛岩石中的挥发物（斑晶中的玻璃和熔体包裹体）中的氢和氧同位素变化提供了有关控制该火山套件喷发历史的机制的重要信息。因此，了解岛上的岩石学和相关同位素变化，有可能预见未来喷发的可能发生及其主要喷发特征。这项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) 大多数岩浆的快速上升和淬灭，保留了含水量和同位素比率的喷发前岩浆信号，由于玻璃暴露而通过再水化进行局部修改海水，以及大气和喷气水；(ii) 管道系统随时间变化，目前以封闭系统脱气为主，导致爆发性喷发；(iii) 控制上升的岩浆与地表水的相互作用，在欺骗岛的两个主要断层系统和不同的岩浆停滞深度产生水火山活动。