Do plumes exist? If so, do plume tails connect hotspots to the core-mantle boundary (CMB), or only to the 660-km discontinuity (between the upper and the lower mantle)? Are they continuous or fragmented? Here, we demonstrate quantitatively that the Hawaiian plume distorts 24-h-period magnetovariational data by providing a continuous electrical connection between the Earth's surface (via the ocean) and the 660-km mid-mantle discontinuity. We extend our analysis to predict how a plume ascending from the CMB should distort magnetic secular variation observed locally at the surface. Hence, the Hawaiian plume is demonstrated to be a continuous feature with a deep-seated (at least mid-mantle) source. Our analysis provides a novel technique for determining whether the Hawaiian plume originates at the mid-mantle transition zone or CMB subject to magnetic secular variation data being acquired locally, as well as allowing the depth of genesis of other mantle plumes to be constrained should further geomagnetic data become available in their vicinity.

羽流存在吗？如果是这样，羽状尾部是将热点连接到核心-幔幔边界（CMB），还是仅连接到660公里的不连续性（上下幔之间）？它们是连续的还是零散的？在这里，我们定量地证明了夏威夷羽流通过在地球表面（通过海洋）与地幔中部不连续660公里之间提供连续的电连接而扭曲了24小时周期的磁变化数据。我们扩展我们的分析，以预测从CMB上升的羽流将如何扭曲在表面局部观察到的磁长期变化。因此，夏威夷羽被证明是具有深层（至少是中地幔）源的连续特征。