In Northeast Japan and Izu‐Bonin, arc volcanoes form in clusters or as cross‐arc chains. Their occurrence emphasizes the non‐uniform distributions of sub‐arc temperature and fluids that control the spacing of arc volcanoes. Here, using 3‐D numerical models, we show that the cessation of back‐arc spreading promotes volcano clustering by triggering the formation of nascent lithospheric drips – downward protrusions of cold and dense lithosphere‐adjacent to the thinned back‐arc lithosphere. The nascent drips interfere with the flow of the hot asthenospheric mantle from the back‐arc toward the arc, leading to gradual development of alternating hot and cold regions beneath the arc. The results indicate that along‐arc variation in the sub‐arc mantle temperature is largest not during back‐arc spreading but after its cessation, explaining the time offset by several million years between back‐arc spreading and volcano clustering in Northeast Japan and Izu‐Bonin.

中文翻译：

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停止弧散布和随之而来的新生岩石圈滴水的推动促进了火山成簇

在日本东北部和伊豆邦宁，弧形火山形成簇状或跨弧链。它们的出现强调了控制弧形火山间距的亚弧温度和流体的非均匀分布。在这里，我们使用3D数值模型显示，弧后扩散的停止通过触发新生岩石圈滴水的形成而促进了火山聚集，液滴的形成是寒冷而稠密的岩石圈的向下凸起，与变薄的弧后岩石圈相邻。初生的滴水干扰了热软流圈地幔从后弧向弧的流动，从而导致弧下交替出现的热区和冷区逐渐发展。结果表明，弧下地幔温度的沿弧变化最大，不是在弧后扩散过程中，而是在其停止后，