The Indian Ocean Geoid Low (IOGL) is the most prominent geoid anomaly (−106 m) on the globe, whose origin remains elusive. In the present study, we investigate the mantle transition zone (MTZ) structure beneath the region using P  receiver functions (PRFs), to examine its role in the genesis of this feature. Results from 3‐D time to depth migration of PRFs reveal a thin MTZ primarily due to an elevation of the 660 km discontinuity. This is suggestive of anomalously hot temperatures in the mid mantle beneath the IOGL region, possibly sourced from the African Large Low Shear Velocity Province (LLSVP). The combined effect of the hot (low‐density) material in the MTZ proposed in this study and the (high‐density) cold slab graves atop the core‐mantle boundary inferred from previous studies can possibly explain this geoid low.

中文翻译：

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印度洋大地水准面以下热幔过渡区的地震证据

印度洋大地水准面低位（IOGL）是地球上最突出的大地水准面异常（−106 m），其起源仍然难以捉摸。在本研究中，我们使用P调查该区域下方的地幔过渡带（MTZ）结构 接收器功能（PRF），以检查其在此功能的产生中的作用。PRF从3D时间到深度偏移的结果表明，由于660 km不连续面的升高，MTZ较薄。这表明IOGL区域下方的中地幔温度异常高，可能来自非洲大低剪切速度省（LLSVP）。这项研究中提出的MTZ中的热（低密度）材料与岩心边界上的（高密度）冷板坯坟墓（根据先前研究推断）的综合作用可能解释了这一大地水准面低。