Earth's mantle transition zone (MTZ) is a possible global water reservoir and may be responsible for long-term (∼100 Ma) ocean-mass regulation. Estimates of water capacities in MTZ minerals are ∼1 wt%, far greater than that of rocks of the surrounding mantle. When water-rich material is displaced from the MTZ, partial melting occurs, generating a sharp reduction in seismic velocities detectable with seismic receiver functions (RFs). We estimated RFs for the MTZ beneath the Yellowstone region using earthquakes recorded by ∼200 stations of the Earthscope Transportable Array. We found many LVZs both above and below the MTZ, consistent with water release upon phase transformation of hydrated MTZ rock into upper- and lower-mantle mineral assemblages with low water capacities. The locations of LVZs are consistent with mid-mantle flow induced by descent of a Farallon-slab fragment and ascent of the deeply rooted Yellowstone plume as imaged by seismic tomography.

中文翻译：

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黄石地区下地幔中地幔水运移的地震证据

地幔过渡带（MTZ）是一个可能的全球水库，可能负责长期（~100 Ma）海洋质量调节。MTZ 矿物中的水容量估计约为 1 wt%，远大于周围地幔岩石的水容量。当富含水的物质从 MTZ 移出时，会发生部分熔化，从而使地震接收器功能 (RF) 可检测到的地震速度急剧下降。我们使用 Earthscope 可移动阵列的 200 个台站记录的地震估计了黄石地区下方 MTZ 的 RF。我们在 MTZ 上方和下方发现了许多 LVZ，这与水合 MTZ 岩石相转变为具有低水容量的上地幔和下地幔矿物组合时释放的水一致。