But what happens to the vast amount of water attached to a slab that descends to the Earth’s core? Yutaro Tsutsumi and colleagues have now answered that question. Their experimental results suggest that the water does not escape from the slabs at the base of the mantle, as commonly thought, even at high temperatures and pressures (Y. Tsutsumi et al. Nat. Geosci. https://doi.org/10.1038/s41561-024-01464-8; 2024).

It is commonly believed that at high temperature and pressures, water is released from the subducting slabs. This process could modify the chemistry of the lowest mantle by hydrating minerals or causing partial melting. However, Tsutsumi and colleagues’ finding challenges this prevailing view. Their results suggest that the subducted water has a minimal effect on the structure and composition of the core–mantle boundary region.

但是附着在一块下降到地心的板块上的大量水会发生什么情况呢？ Yutaro Tsutsumi 和同事现在已经回答了这个问题。他们的实验结果表明，即使在高温和高压下，水也不会像通常认为的那样从地幔底部的板块中逸出（Y. Tsutsumi 等人Nat. Geosci . https://doi.org/10.1038 /s41561-024-01464-8；2024）。

人们普遍认为，在高温高压下，水从俯冲板片中释放出来。这一过程可以通过水合矿物或引起部分熔化来改变最低地幔的化学成分。然而，Ttsutsumi 及其同事的发现挑战了这一普遍观点。他们的结果表明，俯冲水对核幔边界区域的结构和组成的影响很小。