The tempo of subduction-related magmatic activity over geological time is episodic. Despite intense study and its importance to crustal growth, the fundamental drivers of this episodicity remains unclear. We demonstrate quantitatively a first order relationship between arc flare-up events and high subduction flux. The volume of oceanic lithosphere entering the mantle is the key parameter that regulates the proportion and rate of HO entering the sub-arc. New estimates of subduction zone HO flux over the last 150 million-years indicate a three- to five-fold increase in the proportion of HO entering the sub-arc during the most recent global pulse of magmatism. Step changes in HO flux enable proportionally greater partial melting in the sub-arc mantle leading to a flare-up episode. Similar magmatic flare-ups in the ancient Earth could be related to variability in slab flux associated with supercontinent cycles.

中文翻译：

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俯冲水通量波动控制弧中的岩浆爆发


地质时期与俯冲相关的岩浆活动的节奏是间歇性的。尽管进行了大量研究及其对地壳生长的重要性，但这种偶发性的根本驱动因素仍不清楚。我们定量地证明了电弧爆发事件与高俯冲通量之间的一阶关系。进入地幔的大洋岩石圈体积是调节H2O进入弧下的比例和速率的关键参数。对过去 1.5 亿年俯冲带 H2O 通量的新估计表明，在最近的全球岩浆作用脉冲期间，进入亚弧的 H2O 比例增加了三到五倍。 H2O 通量的阶跃变化使得弧下地幔中的部分熔化成比例地更大，从而导致爆发事件。古代地球中类似的岩浆爆发可能与超大陆循环相关的板片通量的变化有关。